ALBERT

Description: This list includes age measurements carried out from December 1968 to October 1969. Archaeologic samples are from Italian and Swat (W Pakistan) territories. All geologic samples come from Italian territory. Chemical techniques remain the same (Bella and Cortesi, 1960; Alessio, Bella, and Cortesi, 1964).

Description: Radiocarbon dates obtained since August 1969 are included in this report. The procedures followed and equipment used have been described previously (Radiocarbon, 1966, v. 8, p. 522-533).

Description: The C14 dates given below are a continuation of the work presented in our previous list (Radiocarbon, 1969, v. 11, p. 451-462), and results obtained mainly during 1969 are described. A new 3.3 L copper counter was put into routine operation besides the 2.7 L stainless steel counter employed heretofore, yielding background counting rates of 8.5 and 5.5 cpm, respectively, when filled with dead CO2 at ca. 1.8 atm.

Description: The following list comprises measurements made since those reported in Radiocarbon, 1969, v. 11, p. 130–136. No changes have been made in measurement technique or in the method of calculating the results described in Radiocarbon, 1965, v. 7, p. 156–161. It was necessary during 1968 to replace all the geiger counters used in the anti-coincidence rings, but the long term stability of background and standard count rates implicit in the use of a 20-week rolling mean has been maintained.

Description: This list contains the results of measurements made during 1967 and 1968. Samples are counted in the form of acetylene gas, as previously, and ages computed on the basis of the Libby half-life, 5568 ± 30 yr. The error listed, always larger than the one-sigma statistical counting error commonly used, takes into account variable laboratory factors, but does not include external (field or atmospheric) variations.

Description: This list includes selected dates of archaeologic samples from DDR, Czechoslovakia, Hungary and the Soviet Union made between 1966 and 1969. As in previous lists the major portion of dates are concerned with Neolithic and Early Bronze age period in Middle and SE Europe.

Description: The C14 measurements reported here were made in this laboratory between October 1968 and October 1969.

Description: The following list presents results obtained during 1968-69 on a series of samples chosen to investigate temporal variations of C14 concentrations in the atmosphere during the past century. Together with data presented previously (Radiocarbon, 1969, v. 11, p. 45-52) they constitute a study of annual variations of C14 activities at N temperate latitudes.

Description: The following list covers samples measured since the last list of atmospheric samples (Radiocarbon, 1967, v. 9, p. 471–476) was written, to determine the increase of the C14/C12 ratio due to explosion of nuclear devices.

Description: The laboratory has been operating more than five years, supported entirely from Venezuelan government funds. Approximately 530 samples have been dated to the end of 1969. Of these, 40% are archaeologic specimens, the majority (141 samples) from Venezuela. Materials from most other countries of Latin America have been processed. The rest of the samples are from research programs of the Radiocarbon Laboratory itself. Thirty per cent of the total are measurements on carbonate species extracted from Venezuelan ground water aquifers.

Description: The present date list covers mainly the datings done from 1964 to 1968. Each sample is measured in one of the two counting units described earlier (Nydal, 1965). The background of the counters has been somewhat reduced during the past few years. Counter 2 with an effective volume of 1.5 L (1.9 L total volume), has a background of 0.9 counts/min, and a recent standard net count of 19.2 counts/min. Counter 3, with an effective volume of 1.1 L (1.3 L total volume), has a background of 2.4 counts/min and a recent standard net count of 14.2 counts/min.

Description: This date list includes those series of samples completed in this laboratory as of November 1969. The b.p. ages are based upon a.d. 1950, and are calculated with a half-life value of 5568 yr. All samples were counted at least twice for periods of not less than 1000 minutes each. Errors quoted are derived from measurement of samples, background, and modern-age calibration, but do not include any half-life error. All samples were pretreated with 3N HCl, and some, where noted, were given additional pretreatment with 2% NaOH for the removal of possible humic contaminants.

Description: The C14 dates given below have been obtained by counting CH4 at 3 atm pressure in a 0.6 L stainless steel counter. Details of procedure are given in the previous lists. Dates are reported in terms of the Libby half-life, 5570 ± 30 years; the errors quoted are based on the standard deviations in counting rate of samples and standards.

Description: The list given below contains the C14 dates obtained for only archaeologic samples, during 1966 and 1967; for the study of the geologic samples dated during the same period, cf. our previous list Gif-III (Radiocarbon, 1969, v. 11, p. 327-344). The same instruments and techniques have been employed.

Description: A third radiocarbon counting system has been established in the Chemistry Department, University of Glasgow, since April, 1968. Operating conditions for the previous systems have remained essentially as described by Baxter et al. (1969).

Description: This list contains mainly radiocarbon dates for Africa. Some results for samples from the ocean floor and from islands in the Atlantic and Indian oceans, as well as a few series of geophysical samples have also been included. The results are grouped into three categories: geologic, archaeologic, and geophysical, and arranged according to the country of provenance, passing roughly from N to S. Descriptions and comments are based on information supplied by the collectors and submitters and on the publications cited. In several cases insufficient information was available, but since it is improbable that it will be forthcoming, the dates have been included.

Description: The following date list includes samples processed by the Illinois State Geological Survey Radiocarbon Dating Laboratory from September 1968 through November 1969. Detailed descriptions of sample methods are published elsewhere (Kim and Ruch, 1969; Kim, Ruch, and Kempton, 1969).

Description: The radiocarbon dates obtained since August, 1968, are reported here. Wood, charcoal, and peat samples are pretreated with dilute NaOH and dilute H3PO4 before conversion to the methane used as counting gas; marls and lake cores are treated with acid only. The reported dates have been calculated using 5568 years as the half-life of C14, 1950 as the reference year. Samples are run at least once in each of two 0.5 liter counters at 3 atm pressure for a minimum total of 15,000 counts. The standard deviation quoted includes only the 1σ of the counting statistics of background, sample, and standard counts.

Description: This list contains a selection of dates from analyses carried out during the past few years. Samples are grouped in geologic-palynologic, and archaeologic sections according to main problem. When influence of human activity on pollen diagrams has been observed it has been explicitly indicated. The descriptions and comments have been written in collaboration with collectors and submitters. For the samples from Switzerland, general reference has also been made to Welten (1958a) and to sections on palynology, geology, and archaeology in work edited by the Schweizerische Gesellschaft für Ur- und Frühgeschichte (1968-1970).

Description: Measurements have continued with both the 1 L and 6 L counters. Results are not corrected for C13 fractionation. Errors quoted refer only to the standard deviation calculated from a statistical analysis of sample and background count rates and the Libby half-life of 5570 ± 30 yr. Pretreatment has been continued as described previously (Shotton, Blundell, and Williams, 1969).

Description: The measurements reported in this list were made in the Louvain C14 Dating Laboratory in 1968 with the 0.6L CH4 proportional counter. The counter generally operates at 3 atm pressure. Samples too poor to provide 2 L methane are measured at 1000 mm Hg pressure. Ages are calculated on the basis of a C14 half life of 5570 yr and are quoted with 1σ counting error. The description of each sample is based on information provided by the submitters.

Description: This date list presents results of samples measured at ISOTOPES during 1968 and 1969 and several measurements made previously for which complete sample data has recently been received.

Description: Both the 2-L counter, described in GSC I (Radiocarbon, 1962, v. 4, p. 13–26), and the 5-L counter (GSC IV, Radiocarbon, 1965, v. 7, p. 24–46) were operated routinely during the past year. Approximately half the determinations reported were obtained from each counter. The 2-L counter was operated at 2 atm except for August and September, 1968, when it was operated for the first time at 1 atm. This allowed for the counting of most small samples without the necessity of mixing with dead gas. The 5-L counter was operated at 1 atm, except for the same period when it was operated at 4 atm. Carbon dioxide is used as the counting gas, and both counters are of the proportional type.

Description: The present list covers samples measured between 1963 and July, 1967. Three previous lists have been published in Leningrad I (Sovetskaya arkheologiya, 1961, p. 3); Leningrad II (The Absolute Geochronology of the Quaternary Period, 1963); and Leningrad III (New Methods in Archaeological Investigations, 1963, p. 9–56). The samples measured include charcoal from cultural layers and hearths, wood from barrows [kurgans] and cemeteries, wooden tools from peat deposits, and mounds, as well as peat and animal tissue.

Description: This list reports the first age determinations carried out by the Freiberg Radiocarbon Dating Laboratory. The preparation of samples and radiocarbon dates were done by the first two authors, who constructed the apparatus; sample descriptions and interpretations of dates were made by the third author.

Description: The laboratory has continued to concentrate on soil and water dating, using the benzene method as outlined in Scharpenseel and Pietig (1969a).

Description: The present date list describes the first stage of a co-operative study on the validity of dating secondary soil carbonates in arid and semi-arid environments of Australia. Because of the complex nature of the physical and chemical variables in a soil environment, many additional samples are being dated from stratigraphically controlled sites before final evaluation of carbonate reliability is possible.

Description: This radiocarbon dating laboratory was established to complement the research activities in the field of archaeology and geology in Korea. The benzene liquid scintillation counting method (Noakes, Kim, and Stipp, 1965; Noakes, Kim, and Akers, 1967) is employed in this laboratory because of its compatibility with other dating methods and future possibility in application of this procedure to the biomedical research field. The chemical process for converting carbon from a sample to benzene used by this laboratory is briefly outlined below.

Description: The dating equipment in the Palaeoecology Laboratory has remained essentially as described in Belfast I (this volume). Rewiring of the counter has increased the detection efficiency slightly. Background count corrected to 1606 mb is now 11.0 counts/min and the net count rate for 95% of the NBS oxalic acid standard is 56.0 counts/min. All charcoal samples have been pretreated in accordance with the schedule given in Belfast I.

Description: The dating equipment in the Queen's University Palaeoecology Laboratory was installed to provide data for research projects, initially dealing with the development of agriculture, in the departments of Botany and Archaeology.

Description: The following list shows the age measurements made at Algiers by the Service des Applications Nucléaires using the C14 method. The laboratory was created in 1965 to answer the increasing demand of the archaeologic research in N Africa, and made its first measurements in 1967. The electronic apparatus employed was completed and calibrated in 1968 and the first tests were performed during the same year. Regular dating-test samples started in June, 1968. The electronic circuits are of commercial origin or made in the C14 Laboratory.

Description: The following list includes C14 dates and deals with the results of the methodological investigations carried out at the Geobiochemical Laboratory of the Institute of Zoology and Botany of the Academy of Sciences of the Estonian SSR in 1967–1968.

Description: A dating system consisting of gas sample counter with internal anticoincidence counter ring, transistorized electronic equipment, and chemical apparatus was developed in the Institute (Felber and Vychytil, 1962; Felber, 1965). A high voltage supply Fluke Model 408B is used. For routine dating, begun in 1965, an improved 2.4 L counter with Teflon insulators is used, shielded on all sides by 20 cm of iron. The counter is run with methane at 760 torr/15°C. Spurious counts are carefully eliminated by a systematic procedure (Felber, 1966). Stability of electronics and counter is checked once a day by taking the topmost part of the peak of Mnα-X-rays following electron capture in Fe-55, radiated through a beryllium window. Checking is done with the same single channel analyzer (switched over to operation with small window) used for energy discrimination (switched over to two discriminator operation) during measurement. If any change should be observed, discriminator settings are corrected. Energy discrimination is not optimized (Felber, 1962) because a neutron generator using (d,t) reaction is run in the same building in which the samples are prepared: the lower discriminator is set above tritium maximum energy at 22 keV, the upper one at 120 keV, the highest possible energy absorption of C14β particles in the special counter. The background is 1.58 cpm, the net contemporary value (95% of NBS oxalic acid standard activity) is ca. 8.8 cpm.

Description: This list includes those analyses completed December, 1968, with equipment and procedures previously employed here.

Description: Natural C14 measurements have been performed at the Dept. of Physics, National Taiwan University since 1965, using a cylindrical proportional counter of 1000 ml (Hsu et al., 1965). The proportional counter is operated with CO2 as the filling gas at a pressure of 1216 mm Hg at room temperature of 20°C. Working voltage is 4.7 Kv, with a plateau length of more than 700 v and a plateau slope of ca. 1% per 100 v. Background is reduced to 5.1 counts/min and the counting rate of the NBS oxalic acid standard is 9.4 counts/min at the normal counting pressure of 1216 mm Hg.

Description: Measurements reported in this paper were obtained with the 4.5 L and 3 L CO2 counters, details of which were given earlier (Radiocarbon, v. 11, p. 423). The automatic data recording system built in 1968 (Hänsel, 1968) is now operating for both counting apparatus. For each one the counts of the guard counters ring (A counts), the total counts of the C14 counter (B counts), the coincidences of central and guard ring counter (AB counts), and the anticoincidences (ĀB counts) are tape punched every 100th minute. By an ALGOL program, all counts are checked first for large disturbances. Secondly, equation B = AB + ĀB must hold (as an integral check for proper operation of logical circuitry and the data recording system) and finally statistical compatibility is examined before age and other data for the actual counting apparatus are computed. This detailed check of counting rates by computer has proved to be very efficient to yield reliable long-term measurements.

Description: The University of Cambridge Radiocarbon Dating Laboratory has been completely rebuilt and modernized, incorporating new techniques developed here for the various stages of measurements. Sample radioactivity is measured in gas proportional counters after conversion to highly purified CO2. Four counters are mounted within a single anticoincidence shield consisting of plastic scintillation material. This is surrounded by a graded cosmic ray shield of low radioactive steel, boron loaded wax, and finally, about 16 tons of ancient low radioactive lead blocks. The electronics are all solid state devices except for the stabilized high voltage supplies.

Description: The following is a list of dates obtained since the compilation of List XII. The method is essentially the same as described in that list. Two CO2-CS2Geiger counter systems were used. Equipment and counting techniques have been described elsewhere (Crane, 1961). Dates and estimates of error in this list follow the practice recommended by the International Radiocarbon Dating Conferences of 1962 and 1965, in that (a) dates are computed on the basis of the Libby half-life, 5570 yr, (b) a.d. 1950 is used as the zero of the age scale, and (c) the errors quoted are the standard deviations obtained from the numbers of counts only. In Michigan date lists up to and including VII, we quoted errors at least twice as great as the statistical errors of counting, to take account of other errors in the over-all process.

Description: Grey et al. (1969) have discussed the problems that arise when using the wet oxidation method for the preparation of CO2 from oxalic acid and suggest that, although offering an effective substitute, the dry combustion method also has problems.

Description: The laboratory routinely operates two proportional counters; one 2-L (Dyck and Fyles, 1962) and one 5-L (Dyck et al., 1965). CO2 is used as the counting gas. The 2-L counter is operated mainly at 2 atm. and the 5-L counter mainly at 1 atm. On occasion the 2-L counter is operated at 1 atm. and the 5-L counter at 4 atm. No changes have been made in the CO2 preparation and purification techniques described in previous GSC dating lists (Lowdon et al., 1969; Lowdon and Blake, 1970).

Description: This list reports C14measurements made in dating projects completed in the year ending December, 1968, and some measurements for projects still in progress. Age calculations are based on C14half-life of 5568 yr and a modern standard of 95% of NBS oxalic acid. Deviations reported are based on counting statistics of sample, background, and modern, and are ±1σ except that when sample count approaches either modern or background, 2σ limits are reported. The laboratory uses liquid scintillation counting of benzene, with Li2C2and vanadium activated catalyst in preparation, as described in Texas IV (Radiocarbon, 1966, v. 8, p. 453–466) and earlier lists. Chemical yields average 85%.

Description: This list reports C14 measurements made in projects completed in the year ending October, 1969, and some measurements for projects still in progress. Age calculations are based on C14 half-life of 5568 years and a modern standard of 95% of NBS oxalic acid. Deviations reported are based on counting statistics of sample, background, and modern, and are ± 1σ except that when sample count approaches either modern or background, 2σ limits are reported. The laboratory uses liquid scintillation counting of benzene, with Li2C2 and vanadium activated catalyst in preparation. Chemical yields average 88%.

Description: SUMMARYExperiments to study the effect of date of sowing at two centres in each of 3 years, 1967–9, are described and the results discussed. The earliest sowing date (early March) gave the highest yield of spring barley at both centres and of spring wheat at Sutton Bonington, but at Boxworth in 1967 and 1969 later sowing (early or late April) gave higher yields of grain, which were attributable mainly to increased grain numbers per ear. It is argued that in 1968 poor weather conditions in July and August resulted in very low 1000 grain weights, and although grain numbers were again higher from late sowing at Boxworth this treatment gave the lowest yields because of poorly filled grain. The date of sowing also affected yields of total dry matter, ratios of grain to straw, leaf-area indices, numbers of grains per ear and 1000 grain weights.

Description: SUMMARYThe response of irrigated, perennial ryegrass to fertilizer nitrogen was studied in four consecutive periods of the growing season by applying 0–350 kg N/ha to a fresh sward at the start of each period, and measuring both herbage dry matter and its content of nitrogen.Responses in yield were highest in the first period, which ended at inflorescence emergence; in this period, both the percentage recovery of nitrogen and the extent of its utilization in producing dry matter were greater than in the later periods. Some damage to the sward was seen following the harvest of grass grown with the high levels of nitrogen in the first period. When the yields were 90% of the predicted maximum the nitrate-N content of the herbage ranged from 1000 to 2000 ppm, except in the first period when it was 200 ppm.The response curves were used to calculate the nitrogen requirements of the grass which would maintain given incremental yield responses. To produce near-maximum yields, irrigated grass swards may require fertilizer nitrogen equivalent to 2 kg N/ha/day prior to inflorescence emergence, and up to 5 kg N/ha/day for the remainder of the growing season.The apparent efficiency of conversion of the radiant energy, usable for photosynthesis, into plant energy averaged 3·2%; it did not vary greatly among the four periods.The experimental results indicate the seasonal requirements of grass for fertilizer nitrogen and some of the implications for animal husbandry are discussed.

Description: SUMMARYFive experiments (1967–9) on soils formed from calcareous drift examined the effects of soil compaction on seedling emergence and yield of sugar beet, also the interaction between compaction and response to nitrogen fertilizer (N) and phosphate fertilizer (P2O5). Some seedbeds were compacted in winter, others in spring and others prepared with the minimum of compaction; each was tested with 0·6, 1·2 and 1·8 cwt/acre N plus 0·8 cwt/acre additional P2O5. All plots were given a basal dressing of 0–8 cwt/acre P2O6 and enough of other major nutrients.Compaction decreased seedling populations in four experiments but increased it in one year, when the weather was dry while the seeds were germinating. However, in every experiment compaction significantly decreased yield of roots and sugar. It also interacted with the fertilizer treatments, significantly on average, increasing nitrogen requirement and decreasing phosphate requirement. On average, 0·6 cwt/acre N and 1·6 cwt/acre P2O5 gave the greatest yield without compaction and 1·2 cwt/acre N and 0·8 cwt/acre P2O6 with compaction.

Description: SUMMARYThe effect of three levels of N fertilizer on the ensiling characteristics of S. 24 perennial ryegrass and S. 37 cocksfoot have been examined during first growth in two growing seasons. The effects of sucrose supplementation, inoculation with Lactobacillus plantarum and wilting were also examined in certain cuts. All silages were made in the laboratory using a small scale vacuum silage technique.The perennial ryegrass herbage was higher in water soluble carbohydrates than the cocksfoot, N fertilizers decreased soluble carbohydrates and dry-matter content in both species. Buffering capacity was not consistently different between grasses or between N levels.Herbage was cut at two stages of maturity in the first year. In the first cut (8 days before ear emergence), perennial ryegrass silages were well preserved irrespective of the amount of N applied to the grass. Cocksfoot silages were well preserved only when the lowest level of N fertilizer had been applied (50 kg/ha). Supplementation of cocksfoot with sucrose prior to ensiling markedly improved silage quality, but inoculation had no effect. In the second cut (26 days after ear emergence) the grasses were higher in drymatter content and showed a lower buffering capacity, but neither ryegrass nor cocksfoot silages were well preserved unless supplemented with sucrose prior to ensiling.In the second year of the experiment only one cut was taken (9 days after ear emergence). As in the previous year, silages made from herbage at a late stage of growth were poorly preserved. Wilting prior to ensiling resulted in well-preserved silages.It is concluded that the need for additives and wilting to ensure satisfactory preservation varies in relation to the variety of grass used and its stage of growth.

Description: Ryegrass was used to remove potassium from two acid soils limed to different pH values. Most non-exchangeable potassium was removed from the unlimed soils (pH 4·5) but differences in removal between pH 5·5 and 7·0 were small. Air-drying the soils after cropping released further potassium into the exchangeable form in amounts independent of soil pH.Equilibrium potassium activity ratios (ARK) after each out declined to small constant values characteristic of the soils. A sandy soil (Woburn) initially contained less exchangeable potassium than a soil with more clay (Sawyers), but after a few crops, ARK, % K in the grass and K uptakes per cut were larger from Woburn soil, showing that non-exchangeable potassium was being released faster than in the other soil.

Description: SUMMARYThe body composition of parasite-infected sheep and of healthy sheep of various body weights and breeding was predicted from tritiated water (TOH) space and body weight using previously published regression equations. Results agreed well with body composition determined by analysis of the minced carcass though a small bias existed in some groups. It is concluded that the equations have a general application to the prediction of body composition in sheep.

Description: SUMMARYSixty-four Blackface ewes in moderately fat body condition, were divided into two groups at 17 days before a chemically synchronized mating. One group was penned indoors (sheltered group), the other group penned outdoors in a climatically exposed position and subjected to artificial wetting for 6 h daily (exposed group). The ewes were fed a maintenance ration of 1350 g pelleted dried grass/head/day indoors and 1500 g outdoors.The treatment was continued from 17 days premating to 25 ± 3 day post-mating. Immediately after mating 16 ewes from each group were interchanged between the two environments. Matings and returns to service were recorded, and at 25 ± 3 days after first mating the ewes were slaughtered. Counts were made of active corpora lutea and embryos; retarded embryos were distinguished. Fresh weights of the ovaries, pituitary, thyroid and adrenal glands were obtained.Body condition of the ewes within the two environments was maintained. The mean ovulation rates of ewes holding to first service were significantly different (exposed group, 1·52; sheltered group, 1·86). There was no difference between the treatment groups in the number of ewes returning to service, but there was some difference in partial embryo loss, most of which occurred outdoors on or about day 14 or 15 postmating. The results suggest that ovulation rate and possibly early embryo mortality can be influenced by cold stress.

Description: SUMMARYForty-six cows in store condition (mean ± S.E. body weight of 366 ± 8 kg) were fed individually either 3 or 4 kg of coarsely rolled sorghum grain/head/day for the last 100 days of pregnancy and the subsequent 70 days after parturition. Eleven of the cows on each level of feeding had their calves weaned at 3 days of age.For the last 100 days of pregnancy, 3 kg of grain/head/day was an adequate ration for survival, but cows fed this ration lost a mean of 34 kg of body weight over this period compared to 8 kg by cows fed 4 kg of grain/head/day. Only 78% of the cows fed 3 kg grain/day survived to 70 days after parturition, whereas all cows fed 4 kg/day survived. There was a 44% incidence of retained placentae and metritis in cows fed 3 kg grain/day whereas those fed 4 kg/day had only an 18% incidence. Weaning of the calves at 3 days of age reduced the body weight loss of the cows by a mean of 40 kg over the first 70 days of lactation, but the effect was less for cows fed 3 kg grain (27 kg) than for those fed 4 kg grain (53 kg).Birth weight of the calves was not affected by the level of grain fed to the cows, but calves weaned and given 3 kg of milk/day plus a 50/50 creep of lucerne chaff and sorghum grain grew faster than calves not weaned and given only a sorghum grain creep.The omission of a source of calcium in the grain ration resulted in no apparent adverse clinical effects in the cows. The Na:K ratio of the saliva indicated that nine of the cows had been depleted of Na.

Description: SUMMARYHeat-exchange chambers, one for heating and one for cooling, were surgically embedded beneath the skin of a sheep. The intensity of heating and cooling was progressively increased, producing average subdermal temperatures up to 50·3 °C over one chamber and down to 21·0 °C over the other. The normal subdermal temperature was 37·7 °C.Moderate heating produced a small increase in the length growth rate of wool over the hot chamber. Higher temperatures caused a marked reduction and with still further heating there was almost complete cessation of wool growth.In contrast to heating, cooling always caused a suppression of wool growth which became more pronounced as the degree of cooling was intensified. The length growth rate decreased to half of normal at one stage but it never ceased.There was evidence of a slight but progressive decrease in fibre diameter with increasing subdermal temperatures up to 45 °C but at a temperature of 48 °C many of the fibres exhibited a marked thickening. Cooling the skin had little effect on fibre diameter. Pigmentation of the fibres was unchanged throughout the whole range of temperatures used and there was no evidence of change in crimping of the fibres.Heating in the range 45–50 °C produced an increase in epidermal thickness. Sweat and sebaceous glands, and erector muscles appeared unchanged after heating or cooling but innervation of the skin appeared to be reduced by extreme heating.The skin and wool growth over a dummy chamber were normal and similar in all respects to that in other control areas.

Description: SUMMARYOn the feeding regimes examined, i.e. hay ad libitum restricted hay and restricted hay with supplementary glucose, the quantities of extracellular water-soluble polysaccharides in rumen liquor were small (3·6–9·0 mg/100 ml) and could have originated from the diet or the saliva as well as from microbes. The polysaccharides extracted with hot water (fraction B) and acetate buffer (fraction C) were also small in amount in the rumen liquor from sheep on any of these diets (less than 56 mg/100 ml) and were composed of rhamnose—containing polysaccharides, starch-like polysaccharides and xylose polymers. Syntheses of these B and C polysaccharides were found with the hay and glucose diet but the quantities involved were small (12·27 mg/100 ml rumen liquor). Degradation of the polysaccharides occurred at 4–6 h after feeding. The consistently high ratios of rhamnose to hexose in the B and C polysaccharides from rumen liquor suggest that these were microbial in origin. Iodine-staining organisms in the rumen liquor were a small proportion of the total and showed no increases after feeding.

Description: SUMMARYIn each of two years, 36 Blackface ewes were brought to a high state of body condition at mating and in early gostation. At approximately 16 weeks prepartum the ewes were divided into two similar groups and fed to maintain the live weight and body condition of one group (fat), and to decrease that of the other group (lean). At 8 weeks prepartum mean differences of 14kg live weight and two scores of body condition had been created between the groups. During the last 6 weeks of pregnancy food was rationed to all ewes per unit of live weight to provide the theoretical requirements of Blackface ewes in late pregnancy. Both groups of ewes made similar live-weight gains in late pregnancy and blood plasma F.F.A. values confirmed that the ewes had been similarly nourished regardless of live weight or body condition. During early lactation food was restricted to fat and lean groups of ewes for either a 2- or 4- week period followed by ad lib. feeding for the remainder of lactation. A lamb-suckling technique was used to measure milk production during a 10-week lactation. During the first and second weeks of lactation the mean milk production of groups of both fat and lean ewes was approximately 2·1 and 1·3 kg/day for twin- and single-suckled ewes respectively. Ad lib. feeding following restricted feeding during the first 2 weeks of lactation resulted in increased milk production of fat and of lean ewes to mean maximum values of approximately 2·7 and 1·7 kg/day for twin- and single-suckled ewes respectively. In contrast, groups of ewes which had restricted feeding for the first 4 weeks of lactation showed almost no increase in milk production when fed ad lib. During the extended period of restricted feeding the milk production of twin-suckled ewes which were fat at parturition was significantly greater than that of twin-suckled lean ewes but there was no difference with singlesuckled ewes. All groups of ewes lost similar amounts of live weight and body condition during their respective periods of restricted feeding. In the respective 6-week periods following ad lib. feeding the live-weight gain of the lean ewes was significantly greater than that of the fat ewes (339 v. 222 and 356 v. 250 g/day for twin- and single-suckled ewes respectively), but they did not attain parity of live weight by the end of lactation. When fed ad lib. the mean intake of all groups of ewes attained similar maximum values of approximately 2·2 kg D.O.M./day. The results indicate that the stage of lactation is an overriding factor governing the response to increased nutrition and that body condition of ewes at parturition acts as a buffer between nutrient intake and nutrient requirements for lactation. It is suggested that when body reserves of ewes are severely depleted, factors other than nutrient intake may become limiting to milk production.

Description: SUMMARYAn experiment was carried out in which each of thirty-six ewes was offered one of six dietary treatments from the 30th to the 140th day of gestation. The treatments supplied two levels of metabolizable energy (ME) intake (128 and 116 kcal/kg W0.75/day) each at three patterns of protein intake, namely equal increments at 22 day intervals, equal decrements at the same intervals and a constant daily intake throughout. The protein intake patterns supplied a mean daily intake of digestible crude protein of 3·74 g/kg W0.75/day. Nitrogen balances were carried out on four ewes from each dietary treatment during the last 10 days of each 22 day period.Thirteen ewes randomly distributed on all dietary treatments were barren. Mean rate of live-weight gain in the pregnant ewes was 123 g/day compared with 66 g/day in the non-pregnant ewes and was not significantly affected by treatments. Lamb birth weights adjusted to the basis of twins were 3·83, 4·02 and 3·56 kg for the increasing, constant and decreasing patterns of protein intake respectively.Within patterns of protein intake there were no significant differences in nitrogen retention between pregnant and non-pregnant ewes until after 90 days of gestation. Thereafter retention increased in the pregnant ewes offered the constant and increasing patterns of crude protein and remained constant in the non-pregnant ewes. During the same period the retention of both pregnant and non-pregnant ewes on the decreasing pattern decreased.The effects of both energy and protein intake on nitrogen retention in early and late pregnancy were assessed by multiple regression analysis. The results are discussed in relation to other recent findings.

Description: SUMMARYSweating rate and the electrolyte content of secretions from the skin of cattle have been measured on five Bos taurus and five B. indicus cross-bred cows by absorbing secretions into filter papers under polythene disks applied to shaved skin areas on the shoulder, sacral and lumbar regions for 5 min. The increase in weight of the filter paper was taken as a measure of sweating rate and the distilled water eluate from the filter paper was analysed for sodium and potassium. Animals were exposed for 4 h to air temperatures of 20–45 °C at 30% r.h., and for 5–7 h to air temperatures of 40 and 45 °C at 40% r.h. Estimated sweating rates were low by comparison with previously reported values, probably due to rising levels of humidity under the polythene disks during exposure to the skin. B. indicus cross-bred cows had higher sweating rates than B. taurus cows at high air temperatures but the difference between the groups was not significant statistically. Sweating rates were generally highest on the shoulder and lowest on the lumbar region.The amounts of sodium and potassium recovered from filter papers were small and very variable at low air temperatures but increased significantly with air temperature (P 〈 0·01). No significant differences in the amounts of electrolyte recovered from filter papers were recorded between the species groups or between different sites of collection. The secretions from cattle skin at high ambient temperatures contained at least four to five times as much potassium as sodium. Total sodium and potassium loss through the skin of these experimental animals at the highest ambient temperatures was estimated to be no more than 1–3 % of the sodium and potassium intake in the feed. Absorbing sweat on to filter paper as a method of measuring sweating rate and sweat composition is rather less satisfactory for use with cattle than with man.

Description: SUMMARYAn isotope dilution technique has been used to measure the rate of entry of glucose into the metabolic glucose pool and its rate of oxidation in three sheep given diets of barley (85% barley, 15% protein-mineral-vitamin supplement), dried grass or hay. A latin-square design was used and the sheep were fed continuously from an automatic feeding device.Despite large differences in the amounts of α-linked glucose polymer and of crude protein supplied by the diets there were no significant differences between treatments in glucose entry rate, in plasma glucose concentration or in the size of the total body pool of glucose.Calculations based on the specific radioactivity of expired CO2 after 3 h infusions indicated no significant differences between treatments in the percentage of glucose oxidised to CO2 or in the percentage of expired CO2 derived from glucose. The absence of a final ‘plateau’ position in the CO2 activity-time curve, even after 6 h infusions, casts doubt on the validity of these calculations.

Description: SUMMARYMaturation studies were carried out on 241 cattle oocytes. Media used were bovine follicular fluid and growth medium. Both media supported a resumption of meiosis in ca. 80 % of cases, but growth medium proved superior in terms of final maturation.Fertilization attempts were carried out on 564 oocytes following culture (27–32 h) in growth medium. In vitro fertilization attempts (107 oocytes) and in vivo fertilization attempts (82 oocytes) in the rabbit yielded negative results. Following in vivo fertilization attempts in the ewe, ova containing pronuclei as well as apparently normal cleaved ova were recovered.

Description: SUMMARYA greenhouse pot experiment was conducted with paddy rice (Oryza sativa L. var. ‘Nato’) grown on Mountview silt loam at its initial low P level and on this soil receiving preplant unlabelled P applications (medium and high soil P levels). Labelled granular CSP (concentrated superphosphate) alone, a 2/1 mixture of CSP and DCP (dicalcium phosphate) and a 1/2 CSP-DCP mixture were evaluated.Dry-matter yields and tillering increased markedly with amount of applied P on the low P soil, and slightly on the medium P soil; there was no response on the high P soil. Response decreased with decrease in water solubility of the applied P at the low and medium soil P levels. Total uptake of P by rice showed similar trends, except that uptake increased significantly with amount of P applied at the medium soil P level.Percentages of plant P from the labelled fertilizer and uptake of fertilizer P increased in all situations with amount of applied P, decreased with decrease in water solubility of the applied P, and decreased with increase in soil P level. Uptake of soil P increased markedly with increase in soil P level. Soil labelling was much less satisfactory than fertilizer labelling for evaluating the effectiveness of P in different fertilizers.A solution of labelled CSP was applied in a second experiment at time of transplanting and 3 or 6 weeks later. On the low P soil, yields, P uptake and tillering increased with rate of applied P but decreased with later date of application. On the medium P soil, yields, tillering and uptake of P by the grain were rather similar among treatments. Uptake of P in the foliage and mature straw, however, increased with later date of application. These results indicate that late-applied P is readily absorbed by rice but is not effective for increasing yields.

Description: SUMMARYChanges in the concentration of copper in the blood of 241 adult ewes bled 4 times over a 12-month period (and 332 ewes over a shorter period) were analysed to examine sources of variation in the changes. Breed, age and swayback history were the most significant of the factors associated with both the amount and rate of decline in copper level from summer through autumn to winter. The number of lambs born, age of ewe, and swayback history were the most significant factors associated with the increase in levels from winter to the following summer.There was a tendency for the classes of sheep with the relatively higher concentrations of copper in their blood to show less seasonal fluctuation in those levels than classes of sheep with relatively lower concentrations of copper.

Description: SUMMARYEvapotranspiration from spring barley plots grown at a range of densities was estimated using the neutron probe technique. Early in the season rainfall led to percolation and kept the soil at field capacity, but from the beginning of June significant differences were found in the cumulative evapotranspiration. As the crop canopy was complete by this time in all densities, it seems probable that evapotranspiration at this time was dependent on rooting density. Although the total water use at the end of the season was similar at all densities, the more rapid use earlier in the season at higher densities may have led to a reduction in growth at the grain filling stage.

Description: SUMMARYSoils from Broadbalk field were used to find whether differences in K-manuring had altered K:Ca exchange relationships during 100 years cropping with wheat, by measuring cation exchange capacities and quantity/intensity (Q/I) relationships.Cation exchange capacities (CECs) were measured with and without the contribution of the soil organic matter and the following mainly non-significant trends arose during 100 years: (1) The CECs of plots given K fertilizer increased slightly when the organic contribution is included and decreased slightly when it is not. (2) The CEC of the plot given farmyard manure increased greatly when the organic contribution is included and decreased slightly when it is not. (3) The CEC of the unfertilized plot increased very slightly, whether or not the organic contribution is included.The K buffer capacity, the slope of the Q/Icurve when the soil neither gains nor loses K, was related to the K saturation of the CEC better when the organic contribution was omitted from the CEC than when it was included, suggesting that K: Ca exchange measured by the Q/Icurves occurs mainly on the non-organic part of the CEC. Two soils depleted of K had anomalously large buffer capacities, but two undepleted samples behaved similarly.Superimposing Q/Icurves by eye showed no appreciable differences between samples from different years or from different plots, even at large activity ratios. Plotting exchangeable K against I0, the activity ratio when the soil neither gains nor loses K, gave a single curve embracing all plots from all years, similar to the superimposed Q/I curves. Long–term manuring with ammonium sulphate has not affected K–Ca exchange.

Description: SUMMARYThe nitrogenous composition of the water soluble fraction of maturing grass silage was investigated in detail. Empirical methods of group analysis demonstrated the complete absence of water soluble proteins, and that the major changes, involving the formation of amino acids and volatile amines, were completed within the first 2 months of ensiling. These methods were unable to account for a high proportion of the soluble nitrogen. Changes occurring within the soluble carbohydrate and volatile fatty acid fractions indicated that while secondary fermentations occurred some 8 months after ensiling they did not have any marked influence on the nitrogenous components.A detailed analysis of the individual components of the nitrogenous fraction was undertaken using both conventional methods of ion exchange chromatography and techniques developed especially for this purpose (see Hughes, 1969). Selective degradation of the amino acids liberated by the proteolysis of the grass proteins occurred. The volatile basic nitrogen content was comprised of ammonia. The non-volatile amine fraction, which accounted for a considerable proportion of the soluble nitrogen, was mainly composed of putrescine and cadaverine. There was no free histamine and only low concentrations of bound histamine were found. Evidence suggested that these amines were being further metabolized during the storage of the silage.

Description: SUMMARYSixteen varieties of groundnuts were included in a variety trial at three locations in 3 years in Western Nigeria. Significant ‘variety x environment’ interactions were observed, indicating that none of the varieties possessed wide adaptation. It is suggested that Western Nigeria be divided into sub-areas for which varieties showing specific adaptation could be developed.

Description: SUMMARYSurface soils (0–15 cm) from a field experiment on a sandy podzol were used to evaluate the residues from basic slag, Gafsa rock phosphate and superphosphate (using ryegrass in pots), and to measure the solubility and buffer capacity during cropping, and the distribution of the residual phosphate in different particle-size fractions of the soil.After applying P at about 3·6 g P/m2/year for 6 years, residues of the three P fertilizers were equivalent but after applying more P (9–11 g P/m2/year) for a further 8 years, basic slag and rock phosphate gave larger labile P values, were more effective for ryegrass and buffered soils more than residues of superphosphate. The percentage recoveries of P from the surface soils were approximately 7, 40 and 65 % of the total applied in 8 years as superphosphate, basic slag and rock phosphate respectively.Residues from basic slag (mainly 75–20 μm particles) accumulated in the 〈 20 μm fraction of the soil. Rock phosphate (mainly 200–20 μm particles) dissolved more slowly and about one-half of the material 〉 20 μm remained in the sand fractions of the soil.Residues from rock phosphate maintained values of ½pCa + pH2PO4 and pH–½pCa consistent with the solubility of fluorapatite, even when P was removed from the soil by exhaustive cropping with ryegrass. Residues from basic slag were more soluble than hydroxyapatite.

Description: SUMMARYIn two feeding experiments the effects of different sources of protein on nitrogen utilization were studied. Three protein sources were examined in both experiments; (a) soya-bean oil meal; (b) lucerne hay or vetch oat hay, and (c) a mixture of soyabean oil meal and hay. The first experiment was carried out with nine adult rams and the second with twelve growing rams.The results of N balance experiments showed clearly the superiority of the hay ration over the soya-bean meal ration. N retention when the mixed ration was given was greater than on hay alone. No parallel trend was found between the protein digestibility of any of the diets and its efficiency for N retention.With adult sheep a negative correlation between the extent of N retention and blood urea concentration was found; this agreed with our earlier findings. No such negative correlation was found with growing animals.The highest concentrations of the various forms of soluble N compounds such as soluble a-amino N, diffusible N and diffusible peptide N were found in the rumen liquor taken from the sheep kept on the hay diet. The lowest amounts were observed when the soya-bean oil meal diet was given and intermediate amounts with the mixed diet. These trend sappeared to be related to the NPN (non-protein nitrogen) content of the diet, but the amounts of soluble N compounds present in rumen liquor were not directly correlated with the extent of N retention.Concentrations of VFA present in rumen liquor depended primarily on the carbohydrate composition in the diet. The type of protein ingested exerted some influence, particularly on the concentrations of caproic and iso-caproic acid. The ratios of concentrations of the individual fatty acids in blood to the concentrations of the same acids in rumen liquor were found to increase with lengthening of the fatty acid chain.

Description: SUMMARYTwo 1-year experiments are described in which a single dressing of 120 lb N/acre (134 kg/ha) was applied to a grass sward as anhydrous ammonia (82% N), ammonium nitrate (34·5% N) or sulphate of ammonia (21% N) at various dates from December to April. The pattern of primary growth from each of the treatments was recorded from early April until mid-June by frequent sampling of the herbage to determine the dry matter and crude protein yields. At every date of fertilizer application from late January to mid-April the growth rate of the herbage was markedly lower with anhydrous ammonia than with ammonium nitrate. With the December applications the spring growth rate of herbage from the anhydrous ammonia treatment was similar to that from the ammonium nitrate treatment. Applications of sulphate of ammonia gave results almost identical with those obtained from ammonium nitrate. The calculation of the dates on which a yield of 2000 lb dry matter/acre (2242 kg/ha) would have been available for dairy cow grazing showed clearly a delay of 12–15 days where anhydrous ammonia rather than ammonium nitrate was applied. The response to anhydrous ammonia was improved by applying it early in the year but solid nitrogen fertilizers, applied either early in the season or when growth was starting, gave higher yields of herbage than anhydrous ammonia.

Description: Two methods have been used previously to resolve the ‘mineral’ and ‘organic’ fractions of the cation exchange capacities of soils. Williams (1932) and Hallsworth & Wilkinson (1958) used multiple regression analysis to relate cation exchange capacity (CEC) in several soils to percentage organic matter (OM) and percentage clay, and thence to calculate the average values of the CECs of OM and clay. For individual soils, Davies & Davies (1965) and Clark & Nichol (1968) measured the CEC before and after oxidizing the OM with hydrogen peroxide.

Description: SUMMARYStatistical tests were made on the data obtained from 100 non-pregnant lactating cows, whose milk production ranged from 4 to 22 kg/day. The cows were kept in metabolism stalls and fed 37 different rations.The authors have studied the correlation between total water intake, faecal and urinary water losses, absorbed and available water and the numerous other factors which were analysed in each of the 37 rations.Total water intake is closely related to the dry-matter intake and the dry-matter content of the diet; it is related also to the composition of the ingested dry matter but is unrelated to the daily milk production.Faecal water losses are closely related to the dry-matter intake and the dry-matter content of the diet; increase of pentosans and crude-fibre intake enhances the losses.Urinary water excretion is related to the amount of absorbed water and to the dry-matter content of the diet; a highly significant correlation exists also between urinary water and urinary nitrogen and potassium. Daily milk production and urinary water are negatively correlated.Water secretion in the milk depends on the dry-matter intake and on its composition; but there is no significant correlation between total water intake and milk water.

Description: SUMMARYA project has been initiated to study the growth of barley under conditions of partial drought. The method of producing the drought and comparisons of measurements of evaporation using lysimeters and neutron moisture meters are discussed. Good agreement was obtained between the lysimeter and neutron probes in the lysimeter tank and in the field.In the plots subjected to drought the evaporation was reduced by approximately the amount of rain prevented from falling on the plots and, as a result, the reduction in soil moisture deficit was quite small.Estimates of internal diffusion resistance are made throughout a full season.

Description: SUMMARYThe amount of dry matter produced and N taken up by seven grass species and varieties grown in a glasshouse were compared with perennial ryegrass (S. 23) and Italian ryegrass (S. 22) at different day-lengths and light intensities.The ryegrasses Westerwolds, Italian (S. 22) and Perennial (S. 321) yielded more than S. 23. At the smallest light intensities, Westerwolds, Italian (S. 22) and Perennial (S. 24) (S. 321) ryegrasses and Meadow fescue (S. 215) took up more N than S. 23. Westerwolds and Perennial (S. 24) (S. 321) ryegrasses should be useful alternatives to the S. 23 or S. 22 strains as test crops in nutrient experiments in the glasshouse, especially when grown in the dim light during winter.

Description: SUMMARYTwenty-seven sheep feeding trials were carried out on freshly cut Andropogon gayanus, fed daily during three wet seasons, 1966–8.In each year, dry-matter voluntary intake and digestibility were highest during the first part of the growing season and declined with advancing maturity of the herbage. However, at the time of ear emergence in early October, there were small increases in voluntary intake of dry-matter and crude protein digestibility, although further decreases followed after mid-October.Determinations of in vitro digestibility indicated that elongating stems during early October were at least as digestible as leaves.Seasonal changes in crude protein digestibility were much greater than changes in dry-matter digestibility; seasonal changes in feed intake were intermediate. Voluntary feed intake was related to dry-matter digestibility.Voluntary feed intake and digestible crude protein were both closely related to the crude protein content of the forage. It was concluded that crude protein is a useful criterion for predicting nutritive value.

Description: SUMMARYEwes of three breeds, Devon Longwool, Kerry Hill and Welsh Mountain were injected with different levels of Pregnant Mare Serum Gonadotrophin (PMSG) for 3 consecutive years. Within the levels of PMSG examined (0–1500 i.u.) the highest mean litter size was obtained at 1000 i.u. for the Devon Longwool (2·10) and the Welsh Mountain (2·33), and at 1500 i.u. for the Kerry Hill (2·41). This represented a response of 0·66, 1·28 and 0·56 extra lambs born for the Devon Longwool, Welsh Mountain and Kerry Hill breeds, as untreated ewes of these breeds produced 1·44, 1·05 and 1·85 lambs/litter. The lambing percentage attained was, however, lower than the response in litter size indicated, due to the incidence of barren ewes and of lamb mortality.Though the Devon ewes were heavier than the Kerry's, twin lambs out of the latter were bigger than twins from the Devon's. The relationships of body weight and of natural fertility to optimum dosage of PMSG are considered. There is discussion of the maximum litter size and minimum birth weight compatible with the production of viable lambs.

Description: SUMMARYConcentrate diets supplemented with 5, 20 and 40% of a high- and a low-quality hay were given ad libitum to British Friesian steers from 9 weeks of age to slaughter. The intake of dry matter and metabolizable energy was studied over weight ranges from 91 to 363 kg live weight. The quality of hay did not significantly affect the drymatter intake at any of the weight ranges studied. From 91 to 182 kg live weight the daily dry-matter intake decreased as the proportion of hay in the diet increased. Over the weight range from 182 to 272 kg live weight, intake was maximum at the 20% level of hay supplementation, while from 272 to 363 kg live weight, intake increased with increasing levels of hay in the diet. The supplementation of high-quality hay significantly increased the intake of metabolizable energy by animals weighing 91–182 kg. Increasing proportions of hay in the diet significantly affected the metabolizable energy intake at all stages of growth studied.At 18 and 36 weeks of age digestibility and N balance studies were carried out. The metabolizable energy expressed as a percentage of the gross energy and the mean retention time of the diets were significantly affected by the age of animal, quality of the hay and the level of hay supplementation. Nitrogen retention was also affected by the age of the animal but not by the quality of the hay.The relationships between the voluntary intake of dry matter and the metabolizable energy of the diet expressed as a percentage of the gross energy, for different stages of growth, are also presented.The change in the digestibility and the mean time of retention of the diets in the digestive tract with age and the effect of this on the point where physical regulation to intake gives way to physiological regulation are discussed.

Description: SUMMARYTwo varieties of irrigated rice N.P. 130 (a tall variety) and Taichung Native-1 (a dwarf variety of indica rice) were compared in 1966 and 1967 when grown with several amounts of sodium nitrate and ammonium sulphate. Comparisons of ammonium sulphate treated with ‘N-Serve’ or with ‘AM’ against untreated ammonium sulphate were made.Applying more than 60–80 kg N/ha did not increase the number of panicles per m with N.P. 130 but lowered the number of spikelets and filled grain percentage. Up to 120 kg N/ha, panicle number and the number of spikelets of Taichung Native-1 increased significantly but the filled grain percentage was not increased; yield of grain responded significantly up to 120 kg N/ha. Taichung Native-1 yielded more grain and less straw than N.P. 130. Increasing the nitrogen applied significantly increased the yield of straw from both varieties.Ammonium sulphate increased panicle number and reduced the percentage of filled grain compared to sodium nitrate but the increase in panicle number was higher with Taichung Native-1 than with N.P. 130; as a result ammonium sulphate consistently increased the grain yield of Taichung Native-1. When the ammonium sulphate was treated with either inhibitor it gave more grain of Taichung Native-1 than untreated fertilizer; treated fertilizer gave more straw of both varieties.

Description: SUMMARYPigs were fed either at 3, 6 or 12 hourly intervals to a scale based on live weight from 21 kg to slaughter at 79 kg live weight. There was no effect of treatment on daily gain, feed efficiency or killing out percentage. Backfat thickness at C and K was increased by four times-a-day feeding compared with feeding twice or eight times/day, but this increase in fatness was not confirmed by sample joint dissection.

Description: SUMMARYIn a 2-year experiment anhydrous ammonia (82% N) and an ammonium nitrate fertilizer (34·5% N) were applied at three annual rates—100, 200 and 300 lb N/acre (112, 224 and 336 kg/ha)—on an S.24 perennial ryegrass sward. At each rate the two fertilizers were applied either as a single dressing in the spring or as five equal split dressings over the season. Total yields of herbage dry matter and of crude protein were determined by cutting the herbage at approximately the same stage of growth five times each year. On the basis of total yield and seasonal distribution of yield anhydrous ammonia was best applied as a single dressing in the spring, whereas ammonium nitrate was best applied as five equal split dressings over the season. However, in both years anhydrous ammonia applied as a single dressing gave smaller yields and a poorer seasonal distribution of production than did ammonium nitrate applied as five equal split dressings. The factors contributing to the lower yield level with anhydrous ammonia applications are discussed. It is concluded that anhydrous ammonia has no marked advantages over ammonium nitrate as a nitrogen fertilizer for intensively managed grassland.

Description: SUMMARYSix ewes were milked over a lactation period of 12 weeks beginning 2 weeks after parturition. Milk fat, total crude protein, and protein fractions were determined in each weekly milk sample.Milk fat and total crude protein in whole milk increased significantly over the lactation, attaining mean values of 5.8 and 5.9% respectively. The concentration of the caseins, total albumins and β-lactoglobulin in the whole milk also increased significantly over the lactation, with mean concentrations of 4.67, 0.80 and 0.54% respectively. The mean concentrations of these fractions, expressed as a percentage of the total crude protein, were, caseins 78.7, total albumins 13.5 and β-lactoglobulin 9.1.The following fractions, whose mean percentage concentrations in whole milk are given in parentheses, showed no significant trends over the lactation: α-lactalbumin + serum albumin (0.26), proteose-peptones (0.05), globulins (0.06) and non-protein nitrogen (0.35). Expressed as percentages of total crude protein, these concentrations are 4.4, 0.8, 1.1 and 5.6 respectively.The milk constituents synthesized in the mammary gland, i.e. fat, caseins and β-lactoglobulin showed significant correlations in concentration in whole milk as well as significant increases in concentration over the lactation.

Description: SUMMARYConcentrate diets supplemented with 5, 20 and 40% high- and low-quality hay were given ad libitum to British Friesian steers from 9 weeks of age to slaughter.The performance of the animals was studied over 91 kg weight ranges from 91 to 363 kg live weight and from 9 weeks of age to slaughter. In the whole experimental period the daily live-weight gain was significantly greater on diets containing high-quality hay. There was also an increase in the daily live-weight gain in each of the weight ranges studied on diets supplemented with high-quality hay but this increase was not significant at the stage of growth from 272 to 363 kg live weight. As the level of concentrate in the diet increased there was a significant increase in the daily live-weight gain at each stage of growth studied and over the complete experimental period.The mean feed conversion ratio was greater for diets containing low-quality hay. Except during the stage of growth from 272 to 363 kg live weight the proportion of hay in the diet significantly affected the mean concentrate conversion ratio. With increasing levels of hay in the diet there was a significant increase in the total dry-matter conversion ratio.The conversion ratio of metabolizable energy was also increased on diets containing low-quality hay. The proportion of concentrate in the diet significantly affected the conversion ratio of metabolizable energy at all stages of growth studied.There were significant differences in the killing-out percentages, weight and contents of the reticulo-rumen and the omasum plus abomasum expressed as a percentage of empty body weight, with increasing levels of hay in the diet. These measurements were not significantly affected by the quality of hay in the diet.Indirect measurements of carcass composition indicated that the level of hay in the diet tended to affect the amount of fat in the carcass but the amount of lean was similar at the different ratios of concentrate to hay. The ratios of the weight of separable lean to the weight of separable bone in the 9–10–11th rib cut were similar at different levels of hay supplementation. The organoleptic appraisal of sample joints indicated that carcass quality was satisfactory.

Description: Summary:In sheep fed red clover hay nearly 40% of the feed hemicellulose left the rumen undigested and scarcely any of this hemicellulose was digested in the postruminal digestive tract. The caecal microflora from sheep fed the same diet did, however, yield enzyme extracts which readily hydrolysed isolated hemicellulose or xylan preparations. These caecal and rumen microbial extracts, were capable of hydrolysing the hemicellulose in undigested particulate plant material but were not capable of hydrolysing, to any extent, the hemicellulose in undelignified digesta particles from various parts of the postruminal digestive tract. The hemicellulose in delignified postruminal digesta and the hemicellulose polysaccharides isolated from the digesta were hydrolysed by both rumen and caecal hemicellulases. The results are discussed in the light of observations on the postruminal digestion of hemicellulosic material in roughage- and cerealfed animals.

Description: SUMMARYThe ensiling characteristics of grasses and of red clover were examined by means of a small scale vacuum silage technique. Eight grasses, comprising three varieties each of perennial ryegrass and cocksfoot and two varieties of timothy, were evaluated after application of two levels of nitrogen fertilizer. Three varieties of red clover were evaluated at two stages of growth with and without sucrose supplementation during ensiling.Perennial ryegrass varieties contained more water soluble carbohydrates than cocksfoot and timothy varieties. At the low level of fertilizer N, silages made from the first cut in mid-May were all well preserved 3 weeks after ensiling. At the high level of fertilizer only perennial ryegrass varieties and S345 cocksfoot were well preserved. After ensiling for 14 weeks perennial ryegrass silages remained well preserved but secondary fermentation in the cocksfoot and timothy varieties resulted in poor preservation. Silages made from the second cut at the end of May were all badly preserved except for silage made from tetraploid ryegrass at the low nitrogen level.Significant correlations were established between the water soluble carbohydrate content of the grasses and the quality of the resulting silage, but herbage dry-matter content and buffering capacity were not significantly correlated with silage quality.The red clover varieties were lower in water soluble carbohydrate and higher in buffering capacity than the grasses. Although the silages from red clover were well preserved they were of high pH. Supplementation with sucrose significantly reduced pH and ammonia content and increased lactic-acid content.

Description: SUMMARYNineteen male cross-bred lambs, aged between 2 and 5 days, were allotted to each of three dietary treatments. The protein contents of the diets (on a dry-matter basis) were 12·0% (diet A), 28·5% (diet B) and 45·5% (diet C). The energy intakes of groups of lambs within each dietary treatment varied from below maintenance to ad lib.The experimental period was of 3 weeks and the composition of the live-weight gain was estimated by the comparative slaughter method.Body composition within each dietary treatment was highly correlated with empty body weight, but not with the previous energy intake. The fat content of the gain decreased, and the water and protein contents increased, as the dietary-protein concentration increased.When compared at the same empty body weight, the protein content of the fat-free body of lambs given diet C was significantly higher than that of lambs given diet A. This effect of dietary-protein concentration could not be explained by differences in the amounts of protein stored as wool.

Description: SUMMARYEighteen male cross-bred lambs (aged 2–5 days) in two equal groups were given artificial milk diets of either low- or high-protein content; subgroups of three lambs were slaughtered after 2, 4 and 6 weeks on experiment. The composition of the change in empty body weight (E.B.W.), and the chemical composition of the change in weight of the separate compartments and organs, were determined by the comparative slaughter method.Lambs given the high-protein diet made significant gains in weight and in all chemical components in all periods. The composition of their E.B.W. was closely related to E.B.W. regardless of age. Lambs given the low-protein diet made only small gains in weight in 6 weeks, of which 76% was fat. The chemical composition of their E.B.W. was closely related to E.B.W. within each age group. The net gain of protein of these lambs in 6 weeks represented only 1% of the total weight gain, and over 50% of the protein gain was in wool. The skin and blood lost protein during the first 2 weeks, and failed to recover this loss during the remaining 4 weeks. Other organs lost protein initially but recovered this loss between 2 and 6 weeks.It was concluded that the initial loss of protein represented the labile protein reserves of the lamb, and the subsequent recovery was an adaptation to the low-protein diet. Furthermore, the results with both diets indicated that the skin and blood were the most inefficient of the organs in the body in utilizing the available N during a period of protein deficiency, or during a period of abundance in the dietary supply of N.

Description: SUMMARYThe total body content of fat, protein, ash, moisture and energy of 43 male cross-bred lambs was determined after the lambs had suckled the ewe at pasture for between 2 and 5 days. Sixteen lambs were dissected into seven compartments, namely, carcass, skin, wool, blood, viscera (two groups) and vastus lateralis muscle, and the chemical composition of each was determined. The heats of combustion of the fat and fat-free tissues were also determined. The relationships between empty body weight and body and organ composition were described by logarithmic regression equations.

Description: SUMMARYBulk harvests of primary growth were made at intervals during the spring and summer of 2 consecutive years from an ungrazed area of lucerne (Medicago sativa) and the digestibility by sheep was measured. At the same times, shoots of known length representative of the sward were collected, divided into 7·5 cm lengths, and separated into leaf and stem for the determination of ash, nitrogen, cellulose, and in vitro organic matter digestibility.Digestibility and leaf: stem ratio of the bulk harvests decreased and dry matter increased as the season advanced. Leaf composition changed little, but stem increased in lignin and decreased in ash and in vitro digestibility. In vitro digestibility and leaf: stem ratio were highly correlated with sheep digestibility.Chemical composition of shoots of known heights was similar to that of the bulk harvests. Leaf weights/shoot tended to increase linearly with height of shoot, whereas stem increased nearly as the square of the height. Dry matter of leaf and stem were inversely related to leaf:stem ratio. Stem digestibility decreased with leaf:stem ratio and with increase in shoot height.Chemical components of shoot fractions were associated with each other and were largely dependent on the distance from the top of the shoot at which they had been taken, irrespective of shoot height or time of year. Bottom stems had lower ash, nitrogen and digestibility but higher cellulose, dry weight and dry matter than top stems, whose composition approached that of leaves. Leaf fractions showed little consistent trend with position on the shoot.Some of the difficulties in studying changes in plant composition under field conditions are discussed.

Description: SUMMARYThe efficiency of the utilization of the energy of casein in adult fowls at different feeding levels both for maintenance and for lipogenesis, was studied. The casein was utilized for maintenance with an efficiency of 66·6 ± 1·3% of the gross energy and of 83·7 ± 1·4% of the metabolizable energy. For lipogenesis efficiencies were 51·6 ± 2·15%, and 61·3 ± 2·6% respectively.

Description: SUMMARYA field experiment in each year 1963 to 1967 in Suffolk, England, tested the effect on yield of sugar beet of sowing dates ranging from 13 March to 11 May and harvest dates ranging from 20 September to 8 December. Sowings in March or early April gave similar yields of sugar but with later sowings yield decreased progressively faster. The relationship is represented by the equationy = 106·3 (±2·24) + 0·212 (±0·184)x-0·009 (±0·003)x2,y = yield as percentage of mean (60·1 cwt/acre of sugar), x = number of days after 12 March.Delayed harvest increased sugar yield; the relationship is represented by the equationy = 80·22 (±1·51) + 0·836 (±0·09)z-0·006 (±0·001)z2,z = number of days after 19 September. This represents an increase of 0·247 cwt/acre/day of sugar in October and 0·083 cwt/acre/day in November, equivalent to about 2½ tons/acre of roots in October and 1 ton/acre in November.The effect on sugar yield of different lengths of growing period, which ranged from 138 to 271 days, is represented by the equationy = 38·7 (±26·6) + 1·045 (±0·267)a-0·0017 (±0·0007)a2,a = number of days between sowing and harvest.On average, sowing date had negligible effect on sugar percentage at harvest. In 3 years sugar percentage increased after the first harvest to a maximum and then decreased; in 2 years it decreased with consecutive harvests.

Description: SUMMARYData from the experiment described in the first paper of this series were subjected to regression analysis. Lean meat and live-weight gain response to both lysine and crude protein intake was almost linear in period 1 but in later periods little response was evident. Response of live-weight gain to increased energy was continuous though diminishing in the later periods. In periods 1 and 2 lean gains showed positive though diminishing response to energy.In a multivariate regression analysis it was clear especially for younger pigs that the response to dietary lysine for both live-weight and lean meat gains is influenced by the dietary level of crude protein and the energy intake. Separate multivariate analysis for each sex indicated that females are more efficient converters of lysine and energy into live weight and lean meat. Also an interaction between sex and dietary lysine level was suggested.A methodology for an economic analysis taking the joint objectives of total cost of production, speed of grain and quality of gain is established as a basis for design of high profit system of production.

Description: SUMMARYSixty-six Awassi ewes were divided into two equal groups. The sheep were milked twice daily from lambing for 22 weeks. In one group (weaned) the lambs were separated from their dams within 6 h of parturition. In the second group (suckling) the lambs sucked the residual milk after milking for 15 weeks, after which they were weaned. Milking yields, fat tests, lactational persistency and udder health were not affected by the early weaning. The suckling ewes had greater amounts of residual milk and consumed more concentrates. Further data are presented that suggest that there may be a critical period of attachment of at least 10 days following lambing, during which weaning may effect subsequent milk production. The practical implications of these results are discussed in terms of flock management and the intensification of breeding programmes.

Description: SUMMARYA Nigerian, long-season, sorghum produced 15 tons of dry matter/acre in about 155 days, but the grain yield was small (2000 lb/acre or 2242 kg/ha) because only part of the dry matter formed after heading went into the grain. In contrast, an American, short-season hybrid which formed only from one-half to one-third as much dry weight as Farafara, gave over 4000 lb of grain/acre (4484 kg/ha) in 100 days. A Nigerian sorghum of intermediate height and a long-season hybrid, produced by crosses between Nigerian varieties and an American, short-season sorghum, gave larger yields than the tall variety because they formed more heads/unit area and more grains/head.Crop growth rates of the three long-season sorghums sown in June increased to a peak in July, but declined sharply to very small values in September, and then increased again very rapidly at the end of September as heads emerged. The most important factors causing the decline were a decrease in radiation and a loss in dry weight from decay and detachment of dead leaves. An increase in radiation at the end of September and developmental changes associated with head emergence contributed to the increase in growth rates just before heading.A large proportion of the dry weight formed after heading in Farafara accumulated in the stem but a smaller proportion in the other long-season variety and the longseason hybrid. There was an inverse relationship between the increase in stem weight and the yield of grain. For large grain yields, sorghums are needed that will produce heads with sufficient grains to accommodate all the assimilate that the leaves produce at the end of the rains when crop growth rates are increasing.

Description: SUMMARYThe rumen was found to be the main site of metabolism of biuret in sheep adapted to this compound. Some of the biuret which passed into the lower gut could be broken down there but this could account for the breakdown of less than 1 g/day when 15 g was fed. Biuret injected into the jugular vein or entering the bloodstream from the rumen or intestine was excreted unchanged in the urine. Sheep excreted 9–21% of biuret fed in a solid form and 37–39% when it was dosed as an aqueous solution. Sheep not adapted to biuret failed to retain any introduced into the rumen, duodenum or jugular vein.

Description: SUMMARYAn experimental and a conventional grazing system for 7- and 19-month-old dairy replacements were compared during 136 days of the grazing season. In the experimental system A, 24 calves were rotationally grazed around paddocks followed by 24 pregnant heifers which ate the herbage residue left by the calves. The conventional system B consisted of 24 calves and 24 pregnant heifers maintained at the same overall stocking rate as in system A, but the calves and heifers grazed in completely separate rotations. Half the calves on each system were drenched with an anthelmintic at weekly intervals from mid-July onwards to estimate within systems the effect of gastrointestinal worms on live-weight gain.

Description: SUMMARYCarcass yield and chemical composition of edible meat of fifteen fattened yearling rams and fifteen fattened yearling wethers of Sudan Desert sheep were studied. The animals studied were random samples from groups which had been fattened for 2 months on three different rations. They were about 14 months old at slaughter, and their weights at slaughter ranged from 25 to 52 kg. The average dressing percentage for rams and wethers was 53·0 and 52·2% respectively. Warm carcass weights were 20·22 kg for rams and 19·64 kg for wethers, and these carcasses lost 4·2 and 3·1% of their weight respectively, after 48 h storage in the cold room at 0°C. The bone content of carcasses of rams and wethers was 23·4 and 21·3% respectively. The longissimus dorsi ‘loin eye’ area at the 12th rib was 8·6 cm2 and 8·3 cm2 for rams and wethers. The proportions of wholesale cuts in ram and wether carcasses were comparable, whereas the proportions of slaughter by-products varied between the two ‘sexes’. Mean weight of kidney fat in wethers was 50% greater than in intact rams, but the mesenteric and caul fat was heavier in rams than in wethers.Ram carcasses had higher specific gravity than those of wether carcasses. Specific gravity was negatively correlated with fat content and positively correlated with protein, moisture and ash content of the edible meat of the carcass. The regression equations relating specific gravity to the major chemical components of meat had too high standard errors to be of predictive value in a practical sense.

Description: SUMMARYA laboratory investigation was made of the ammonification and nitrification in soil of pure urea with and without pure biuret and pure biuret alone. The soils ranged from acid (pH 5·1) to calcareous (pH 7·9). The work was done at two temperatures 5 and 25°C. The time between adding urea to the soil and the first analysis was from 1 h to 1 week. The soil moisture contents ranged from the wilting percentage to field capacity. In all work involving urea, ammonium sulphate was used as a standard to compare rates of nitrification.Biuret had no detectable effect on the rates of ammonification and nitrification of urea. Biuret by itself nitrified in all the soils at both temperatures being slowest at 5 °C in the acid soil and fastest in the calcareous at 25°C.Neither pH nor temperature appreciably affected the ammonification of urea but both had a marked effect on nitrification. The lower the pH and the lower the temperature the slower the nitrification. Ammonium from urea nitrified faster than ammonium sulphate and on the acid soil only ammonium from the urea nitrified.The moisture content of the soil only affected ammonification of urea slightly but had a marked effect on the nitrification, the drier the soil the slower the nitrification. The same observation applied to ammonium sulphate.

Description: SUMMARYThe free-acid content of grass silages was reduced by the addition of sodium bicarbonate to the silage and increased by additions of lactic acid. In each of four comparisons the addition of sodium bicarbonate to increase pH from about 4·0 to about 5·4 resulted in significant increases in intake of dry matter which ranged from 9·7 to 20·7%. Intake of organic matter was consistently increased by this partial neutralization treatment, but the increases were not significant in all experiments. The addition of sodium as sodium chloride rather than sodium bicarbonate did not alter the intake of a highly acid silage. Addition of lactic acid to reduce the pH of a silage feed from 5·4 to 3·8 resulted in a decrease in dry-matter intake of 22%. The correlation between dry-matter intake and the silage characteristics: titratable acidity, total organic-acid content, lactic-acid content and pH were all significant.It is concluded that the acids produced during the normal silage fermentation can limit the intake of the silage and it is suggested that chemical treatments to preserve wet grass without the presence or formation of large quantities of acids be investigated.

Description: SUMMARYResults are given for a second period of 9 years, 6 on the pattern of 1951–9, with the last 3 years used for ad hoc management experiments. The meteorological specification of a year of ‘irrigation need’ was satisfied in 4 years: there were good responses in 5 years. During the first 6 years, out of twenty-four sets of crop yields (from eight different crops), very good responses were obtained on nine, good responses on eight, and zero or very slightly negative responses on the other seven.A general theory of the inter-relationships of growth and water, and of growth and radiation, leads to an expressionk = 39ε t ha−1 cm−1,as the maximum possible response to irrigation in terms of total dry matter produced, where ɛ is the fraction of solar radiation fixed by the crop (ɛ has a range 50–100 × 10−4 for good to very good farming) when irrigation is needed. The ‘need’ is defined throughY = k(ET + De − Dm),where Y is the yield, ET is the total potential evaporation, De is a limiting deficit up to which there is no check to growth, and beyond there is no growth, and Dm is the maximum deficit experienced by the crop at the time of measuring Y. The agronomic object of the experiments is to determine De, i.e. what reserve of soil water can be used by the crop before irrigation is necessary.

Description: SUMMARYThe effect of fatty acid chain length and unsaturation on digestibility in sheep were examined using partially purified samples of lauric, myristic, palmitic, stearic, oleic and linoleic acids. The digestibility of the fatty acids was relatively constant with only a very slight decrease on increasing chain length. There was an extensive hydrogenation of the unsaturated fatty acids.The corrected digestibility coefficients for lauric acid was 91%, myristic 86%, palmitic 87% and stearic acid 81–83% whereas the corrected digestibility coefficients for oleic and linoleic acids were calculated at 87 and 93% respectively. The digestibility coefficients for the saturated fatty acids are higher than similar estimates that have been reported for non-ruminants. It is suggested that the ruminant is better able to utilize saturated fatty acids than the non-ruminant.