ALBERT

Description: 1. A survey of the trade in fat cattle, calves and sheep through the collecting centres of the Ministry of Food has been made for the counties of Anglesey and Caernarvon.2. The results show that the Anglesey stock are invariably heavier and in better condition and marketed slightly earlier in the year, than those of Caernarvon.3. The imported fat cattle were heavier and more uniform than the home-bred.4. A check has been made of the variations in live-weight of fat cattle according to colour. Invariably the Black cattle (Welsh) have been lighter, and the Red/White (Hereford) heavier than the average live weight of all cattle of both sexes.5. The bulk of the meat produced in the two counties is delivered during the autumn months, confirming the experience that the winter fattening of cattle is not now widely practised.6. In sheep husbandry the two counties are complementary. The small draft mountain ewe, crossed with a heavier type ram, is capable of rearing a fat lamb practically equal to her own body weight in less than 6 months.7. Losses in mature ewes and rams are suspected to be high because of the small proportions of them, in relation to the population figures, that are delivered to the collecting centres.

Description: The follicle population of the Blackface breed (‘double-coated’) was followed in skin samples taken from four lambs at eight intervals between 3 days and 43 weeks of age. The follicle population differs greatly from that of the Romney and Leicester breeds previously studied (Burns, 1949).1. At 1 month old the secondary/primary follicle ratio (S/P) was slightly lower than the Leicester and much lower than the Romney, and the difference became accentuated with age.2. Fewer secondary follicles are developed after birth than in the Leicester or Romney, although the period during which they can be developed is longer, extending at least to 12 and possibly to 17 weeks after birth.3. The follicle density is less than half that of the Leicester, but the difference in S/P ratio is not sufficiently large to account for this, which is mainly due to the Blackface having a much lower density of primary follicles at birth.4. The possibility is suggested that the secondary follicles arise as a result of ‘induction’ by ‘follicle organizer’ coming from primary follicles in a quantity which decreases with advancing age. It may be that when the primary density is high the areas affected by organizer from each primary overlap, providing sufficient organizer to permit of numerous secondary follicles developing at a late post-natal stage, as reported in the Merino.5. The Blackface contrast with the other breeds in that its primary follicles are conspicuously larger than its largest secondary follicles. All primary fibres are medullated except when about to shed, but many secondary fibres are free of medulla. Kemps are produced only by primary follicles, some of which however produce long ‘hair’ fibres.6. Many fibres which grow strongly medullated fibres during summer change to the production of non-medullated fibres in winter. The shedding of the kemps in spring should probably be looked upon as physiologically an autumn moult, since the fibres cease growth and produce ‘brushes’ during the autumn.

Description: Records for milk, fat, solids-not-fat and fat percentage over forty-eight complete lactations were used as uniformity data to determine the relative efficiencies of a variety of experimental designs used in dairy husbandry experiments.In general, it was found that:1. Experiments conducted during the earlier part of the lactation are more efficient than those conducted during the later part.2. Three-weekly periods are generally more efficient than 5-weekly periods.3. If 3-weekly periods are used, then extending the time of the experiment over four such periods instead of three reduces the error. The converse is the case with 5-weekly periods since the experiment is carried over into the highly variable later part of the lactation.4. Grouping the animals according to the yields recorded during the first 40 days of lactation does not appear to reduce the error.An analysis of covariance using the pro-experimental records of the performance of the animals has been carried out on ordinary group trials and it is hoped to publish the results at a later date, but investigations on the data have shown that both reversal and Latin square designs are more efficient than ordinary group trials even when such an analysis is performed.

Description: The weight, length and quality (fineness) of wool produced at different times of the year and under different nutritional conditions has been determined over a period of three years by clipping at monthly intervals the wool grown on delineated skin areas of sheep. The treatments consisted of(a) wet ewes, grazing on pasture all the year, subjected to high and low levels of feeding during the ‘dry’, pregnancy and lactation periods;(b) dry ewes and lambs fed differentially on grazing during the winter and spring;(c) wet ewes fed in stalls on a diet of constant composition at rates sufficient to maintain constant effective body weight (i.e. making allowance for pregnancy increase and fleece weight increase). A small number of these ewes was also subjected to increased environmental temperature during the winter.The experiments have shown the existence of a marked seasonal rhythm in wool growth having a maximum in January (midsummer) and a minimum in July (midwinter). Changes in weight of wool grown are caused by sympathetic changes in both length and diameter. At the same level of feeding the rate of wool growth in midwinter is about onethird of that in midsummer.The nutritional demands of pregnancy reduce the rate of wool growth in winter and those of lactation delay the rise in production in spring. Nutrition also plays an important part in determining the time of the maximum and minimum. In dry sheep the maximum tends to occur before midsummer when pasture growth is at its best, but lactation in wet sheep prevents the expression of a maximum early in the summer, so that in these ewes it generally occurs after weaning, and therefore after midsummer. The level of nutrition also determines within limits the magnitude of the maximum and minimum.The fundamental cause of the seasonal rhythm of wool growth remains obscure. Nutrition, pregnancy and lactation can modify the rhythm, but it exists strongly even when variations due to these are eliminated. The seasonal rhythm of solar radiation has recently been shown to influence rate of wool growth, particularly during winter, and though this is undoubtedly one factor it is not the only one. Temperature has been suggested elsewhere as a possible cause, but the experiments described do not support the theory that environmental temperature has any direct effect on wool growth. It is suggested, however, that the seasonal rhythm of temperature may be a second factor.

Description: The survey shows that objective estimates of the yield of maincrop potatoes can be obtained from small samples carefully selected and dug by hand. Samples taken from about 1000 fields gave estimates of the mean yield of all counties sampled with a standard error due to sampling of less than ± 0·2 ton/acre. The precision of the estimate could have been improved by a better distribution of samples among counties.The results point to underestimation on the part of the official estimates, in each of the 3 years, especially in the case of high yields in particular counties, and in particular years. The discrepancy between the official and the survey yields is of the order of 1¾ tons/acre, after all necessary corrections have been applied to the survey yields.The experience gained in the survey indicates that the method of sampling adopted provides an accurate and reliable method of estimating the yields of potatoes which could supplement, and, possibly, ultimately replace the present official estimates if more accurate estimates are required. A national scheme, properly designed, which would include all the potato-growing areas in due proportion should not be unduly expensive to operate. Estimates so obtained would not only be generally more accurate than those obtained by the present official method, but, perhaps more important, would indicate far more closely the fluctuation in yield from year to year.

Description: 1. Unlike many other mammals, the calf is capable of responding to pituitary injections almost from birth. Age has little effect on the ability of the follicles to develop during a series of a.p.h. injections, the follicular response generally being as good 3 weeks after birth as in calves 6–8 months old.2. Ovulation can occur spontaneously in the a.p.h. treated calf before the end of the first month of post-natal life.3. Ova obtained from such ovulations are capable of fertilization, although the percentage becoming fertilized is very low. This is thought to be due to the infantile state of the Fallopian tube and the difficulty in inseminating into the uterus, rather than faulty maturation of ova.4. Although many follicles (10–60) can develop during a series of a.p.h. injections, superovulation was not consistently obtained either by intravenous injections of a.p.h., l.h. or p.u., or combinations of any of these three.5. Superovulation can generally be obtained, with the formation of many corpora lutea, if the a.p.h. treatment is repeated a second time after a period of luteal activity.6. The inhibitory effect of a corpus luteum on ovulation in cattle can be overridden in tho a.p.h. treated animal if suitable quantities of a.p.h., l.h. or p.u. are intravenously injected when the newly formed follicles are approaching maturity.7. Ovulation in the calf at all ages up to 8 or 9 months of age, either in the presence or absence of luteal tissue, is unaccompanied by oestrus. Oestrus, when occurring during a series of a.p.h. injections, commenced after 90–100 hr. of treatment. In such cases slaughter has always revealed the presence of luteal tissue, indicating that ovulation during a ‘silent heat’ had occurred before the commencement of pituitary treatment.8. Great individual variation exists in the ability of the ovary to respond to pituitary injections. This insensitivity to gonadotropins is not confined to young calves and has been observed in calves 4–6 months of age.

Description: 1. An EEL mains-operated colorimeter has been calibrated to obtain rapid estimates of the concentration of spermatozoa in bull semen.2. A general linear calibration relationship has been calculated giving h, the estimated concentration of spermatozoa per ml. of the original semen, aswhere d is the dilution factor and Pd is the absorptiometer reading.3. Under the circumstances of the experiments described, the accuracy of estimates from the above relation was about 1%, and it is considered that the instrument may be effectively used in semen determinations for artificial insemination and in most cases where a rapid determination is required.4. Attention is drawn to the desirability of using standards and occasional check calibrations, and to the possibility that in routine use results may be slightly less accurate than those given above, which were obtained with laboratory determinations.

Description: 1. The resting heart rate of cocks and hens was measured in varying degrees of heat stress, and during acclimatization to heat.2. When the rectal temperature was below 110°F. (43·3° C), the heart rate varied inversely with the severity of the climate up to an air temperature around 99° F. (37·2° C).3. At air temperatures of 99° F. (37·2° C.) and above the heart rate was nearly constant over a wide range of rectal temperatures below 110° F. (43·3° C). It averaged about 50 beats/min. less than in an equable climate.4. Above 110° F. (43·3° C.) there was an increase of about 30 beats/min./° F. (17 beats/min./° C.) rise in rectal temperature. The rate equalled that found in an equable climate, when the rectal temperature reached 111–112° F. (43·9–44·4° C). Over this zone of body temperature the fowls were often agitated.5. In severe heat stress there was a slight fall in the heart rate on acclimatization, but this was small compared with the effect of climate.6. In severe heat stress the heart rate during the day was slightly higher than that at night.7. The relation of these findings to the mechanism of temperature regulation is discussed.

Description: 1. The extraction of leaf protein from autumn-grown perennial ryegrass is described.2. The composition, chemical analysis and rate of feeding of two mashes compared in the experiment are given. The same basal cereal mixture was used in each ration, with fish meal added to one and leaf protein and minerals to the other.3. Two groups of three birds were kept on each ration. Nine-month-old Brown Leghorn × Light Sussex pullets, in full lay, were used.4. The birds were given a 6 weeks' preliminary period on a uniform ration to accustom them to the experimental conditions and to ascertain their potential egg production.5. In a 10-week feeding trial no difference occurred in the number of eggs or the total weight of eggs laid by the birds fed on either ration.6. A small loss of body weight occurred in the birds in both treatments.7. Egg-quality determinations indicated that the specific gravity of the eggs was not affected by the differential feeding. Yolk height was greater in eggs from birds fed on the ration containing fish meal. This ration also resulted in a higher number of eggs with rough shells and containing a higher content of foreign bodies.8. The eggs from both treatments had low ‘Yolk-colour indices’, showing that the leaf xanthophylls were not present in quantities in the leaf-protein extract.

Description: A uniformity trial on groundnuts has been analysed and the results discussed. Plant number is less variable than yield and less sensitive to shape of plot and of block. For yield, long narrow plots are more efficient than shorter and wider plots, in all shapes and sizes of blocks and in Latin squares. The plots should not be arranged end to end along the contours, but side by side, either singly or in pairs, forming compact blocks.The regression of the plot variance of the mean yield per unit area on size of plot approximately follows a linear logarithmic relationship. A similar relationship holds for plant number. The value of the regression coefficient b′ is low and it has been shown that, as expected, there is considerable gain from the use of small blocks. The efficiencies of various confounded and incomplete block designs relative to designs in larger blocks have been determined for some particular layouts, and values for other layouts, ignoring shape of plots and of blocks, have been obtained by interpolation.The field used for this uniformity trial appears equally variable in all directions.

Description: A simple method to determine the expectation of selected minimum rainfall has been developed on the assumption that monthly or seasonal rainfall is normally distributed over a period of years. Although it is realized that a perfectly normal distribution cannot be obtained, practical experience has shown that the assumption leads to no serious discrepancies and the advantage of simplicity is considerable. A detailed example of its use to forecast the agricultural potentialities of dry lands is given.

Description: 1. A digestibility trial is described using sheep fed on the product remaining after herbage leaf-protein extraction.2. The material gave an analysis of 25.7% dry matter, 16.2% crude protein, 0.26% phosphorus, 1.26% potassium and 1.13% calcium.3. The animals showed no loss in body weight during the feeding period.4. The material was of low palatability, and the sheep consumed a maximum of 2½ lb. of dry matter per head daily.5. The average digestibility coefficient of the dry matter was 52.1% and that of the crude protein 67.6%.6. Nitrogen balance determinations indicated a sufficiency of protein in the feed.7. The material barely supplied sufficient potassium and was inadequate in its supply of phosphorus and calcium.

Description: As part of the overall programme of research directed towards an understanding of fertilizer needs of crop plants in East Africa a study of the nutrition of maize in sand culture has been made.The purpose of the work was to study growth and yield in relation to changes in the proportion and concentration of the major nutrients, nitrogen, phosphorus and potassium, and if possible to relate the results to the field behaviour of the crop in fertilizer trials conducted by another section of this organization. Simultaneously studies of the uptake of nitrogen and phosphorus were also undertaken. These latter are discussed in the second paper of this series.This first paper deals only with growth, yield and nutrient content in relation to the nitrogen phosphorus balance, though the methods now to be described were common to all experiments.

Description: 1. Pregnancy and lactation had no effect on the digestibility of the dry matter and nitrogen-containing constituents of the ration of Cheviot ewes fed at a constant level.2. The water consumption of the pregnant ewe was almost doubled during gestation.3. The digestibility coefficients of dry matter and nitrogen in both pregnant and barren ewes fell considerably from November until the beginning of the following April.4. The average nitrogen content of a normal fullterm Cheviot foetus was approximately 99 g.

Description: 1. Earlier work on the digestibility of Calluna vulgaris has been briefly reviewed.2. Determination of the digestibility of heather has been made by two methods, viz. (a) the conventional procedure involving the use of metabolism crates and (b) the lignin-ratio technique applied to tethered sheep.3. A diet consisting of heather alone, and fed in metabolism crates, proved unsatisfactory as a result of low feed intake. Agreement between duplicate sheep in respect of digestive capacity was also poor.4. Satisfactory feed intakes were attained when heather was admixed at levels of 40 and 70% with hay. At both levels the digestibility of the organic matter was approximately the same, and agreement between sheep was good except for crude protein.5. The lignin-ratio technique applied to tethered sheep gave digestibility coefficients for organic matter which were consistent with those obtained by the conventional method; the values for crude protein were somewhat higher. While the organic matter of 10-year-old heather was digested to about the same extent as that of 4-year-old heather, its crude protein digestibility was rather less.6. The advantages and disadvantages of both methods have been discussed; it has been concluded that the lignin-ratio technique is likely to play a useful part in future work of this kind.7. These preliminary results suggest that heather has a higher nutritive value than earlier work would indicate, and that even the winter foliage may compare favourably with hay of moderate to poor quality.

Description: 1. A semi-lethal gene combination has been found in hexaploid species hybrids involving some strains of Triticum macha, but not in comparable hybrids involving other strains of T. macha. The production of these semi-lethal hybrids can be explained by the interaction of two genes designated as ma and mb.2. The gene ma is carried in some strains of T. macha. The gene mb is carried in the third chromosome set of all other hexaploid species of Triticum, in Aegilops squarrosa and in Aeg. cylindrica.3. The semi-lethal gene combination has been found between species which would otherwise produce fertile hybrids and between species which would otherwise produce sterile hybrids. The semilethal gene combination occurs between species which do not overlap geographically.4. The distribution of the genes ma and mb shows that the gene ma originated in T. macha and that the gene mb originated in Aeg. squarrosa and was introduced from there, during the course of evolution, into the hexaploid species of Triticum (probably excluding T. macha) and into Aeg. cylindrica.5. Meiosis in semi-lethal plants was comparable to meiosis in normal plants. But the semi-lethal plants showed a reduction in fertility, probably as a result of their poor vegetative growth.6. The chromosomes of T. macha and T. vavilovi have been no more structurally differentiated than the chromosomes of the other hexaploid species of Triticum.7. The present study has confirmed that the third chromosome set of the genus Triticum has been phylogenetically derived from Aeg. squarrosa.

Description: 1. Piglets reared in a cold building but in pens provided with electrically warmed or wooden beds weighed considerably more at 8 weeks old than piglets reared in pens with solid concrete floors covered with thin permeable cork-tar bricks. At 3 days and 3 weeks old there were no differences in live weight between the three groups.2. Before weaning at 8 weeks old the piglets reared on concrete floors had very much poorer appetites for solid food than had those from the other two groups.3. Although the blood haemoglobin concentrations of piglets on warmed and wooden floors rose between 3 and 8 weeks of age, the haemoglobin concentrations in the group on concrete floors fell. The differences in concentrations between groups at weaning just failed to be statistically significant at P = 0·05.4. Under the conditions of this experiment the provision of electrically warmed or wooden floors diminished but did not eliminate the incidence of a pathological liver condition in pigs which has been attributed to poor housing conditions.5. The low weaning weights, poor appetites, low haemoglobin concentrations at weaning and the presence of the liver disease in piglets born on concrete floors were probably interdependent, but the mechanism and direction of this interdependence could not be explained from the data collected.

Description: 1. The rectal temperature of piglets was determined (a) at intervals from birth up to 18 days, (b) at the same time daily until the piglets appeared to be fully thermoregulated.2. The rectal temperature of a vigorous piglet during parturition may be as high as 104–105° F.3. During the first few minutes after birth the temperature falls to about 100° F., partly as a result of the lower temperature of the external environment and partly as a result of rapid evaporation of amniotic fluid with which the young pig is covered. The fall in temperature is greater with lighter pigs than with heavier pigs.4. The temperature falls until the young pig finds its way round to the teats and starts to suckle. This struggle and activity of suckling together with the warmth in the sow's nest causes a temporary rise in temperature. During the first rest the temperature falls again to about 100° F., but vigorous pigs have a normal temperature within 12 hr.5. Piglets deprived of milk after 5 hr. and 16 hr. suckling experienced a more or less steady fall in temperature to about 98° F. in 2–3 days, when the pigs were comatose and were killed. In the case of a pig which had suckled for 7–8 days the temperature remained more or less normal for 2 days and then declined to 95° F. during 5–6 days. The length of survival depends largely on the initial weight, i.e. on the reserves accummulated during the suckling period, and possibly on the thickness of the insulating layer of subcutaneous fat.

Description: 1. A feeding trial is described including four groups of cattle fed on grades I, II and III silages and on swedes, straw and oats respectively.2. The live-weight gains made are recorded, together with the rate of dry-matter intake.3. The efficiency of the dry matter of the diets was calculated.4. All three grades of silage produced a significantly greater rate of fattening than swedes plus straw and oats. There was no significant difference between the fattening values of the three grades of silage.5. The dressing percentages found for 100 silagefed and 71 swede-fed cattle are given. The swedefed cattle yielded a greater average dressing percentage.6. It is suggested that the higher dressing percentage found for root-fed cattle as compared with silage-fed cattle can be attributed to the more rapid elimination of dietary water from the body in rootfed cattle.7. An animal behaviour study is described, the time spent by cattle on the four diets, eating, cudding and lying down, being determined.8. Cattle fed on grass silage spent longer on feeding plus cudding than swede-fed cattle.9. An experiment is described designed to determine the effect of the dry-matter percentage of the diet on the dry-matter intake of ruminants.10. The results indicate that when ruminants are subsisting on a diet consisting solely of succulents, the dry-matter intake is depressed when the dry-matter percentage of the diet falls.

Description: Ayrshire Cattle Herd Books for the years 1927, 1946 and 1947 were examined to study the breed structure. Extended pedigrees of a sample of registered females showed that more than half their genes had come from eight herds. Most of the genetic contribution of these herds comes through the bulls they breed.Herds were divided into: breeders' herds (a), breeders' herds (b), multipliers' herds (i), multipliers' herds (ii), and herds registering males only. The function and numerical importance of each group is shown. The position of any one herd in the breed hierarchy is unstable. Changes in the extent of specialization of herd function between 1927 and 1946 are described.The Ayrshire breed structure is discussed in the light of its implications on the effective size (N) of the population and on the selection of bulls for breeding.

Description: A study has been made of the relationships of sterile Friesian bulls manifesting ‘knobbed’ spermatozoa, and the conclusion drawn that the characteristic defect of the acrosome is due to an autosomal sexlimited recessive gene (kn).

Description: 1. Chromosome pairing has been studied in twenty-two different sterile F1 hybrids involving the genera Aegilops, Agropyron and Triticum, together with their colchicine derived amphidiploids having chromosome numbers of 2n = 42, 56 and 70. Cytological evidence has been correlated with male and female fertility, while chromosome pairing in the parents has been studied in relation to their amphidiploids.2. Some of the sterile F1 hybrids showed little or no pairing, while in others the pairing was appreciable. There was an association of the amount of pairing with the parental combinations used in the production of the hybrids in that the interspecific hybrids were characterized by a relatively high degree of pairing, particularly those with 28 chromosomes, while the intergeneric hybrids either lacked pairing or showed a low incidence.3. In the A1 amphidiploid generation, chromosome pairing was in all cases high, and in some cases almost complete. In all cases multivalent formation in the amphidiploid was lower than bivalent formation in its undoubted F1 hybrid. Different amphidiploids showed various degrees of differential affinity. Univalent formation occurred in some amphidiploids, while bivalent formation in some was increased by a loss of chromosomes.4. In all cases there was a reduction in chiasmata per nucleus and chiasmata per bivalent in the amphidiploid compared with its parent species. Reduction values were not directly associated with any increase in chromosome number of the amphidiploid, nor with the presence of multivalents.5. No confirmation could be obtained of the view that multivalent formation in amphidiploids is a more generally sensitive index of chromosome homology than bivalent formation in the undoubted F1 hybrid. The absence of multivalents in an amphidiploid does not disprove the existence of structural chromosome homologies between the two parents.

Description: Six Romney Marsh ewes exposed daily in a hot-room to temperatures averaging 105° F. dry bulb and 87° F. wet bulb for 2 months prior to the start of the breeding season all experienced oestrus and, as a group, at the same time of year as non-heated controls.However, when maintained under daily hot-room treatment throughout the pregnancy period only one ewe lambed, suggesting an adverse effect of high temperature on gestation.In a further experiment to confirm this, eight control ewes all lambed, average birth weight of lambs being 9 lb. 5 oz. Of six experimental ewes exposed to temperatures of 107° F. (dry bulb) and 92° F. (wet bulb) for 7 hr. daily during the last third of pregnancy, one failed to lamb and the lambs averaged 7 lb. 15 oz. A further six experimental ewes exposed to similar room conditions for the last two-thirds of pregnancy produced still smaller lambs, averaging 6 lb. 11 oz. at birth, and three ewes failed to lamb.The yield of lamb per ewe was 9 lb. 5 oz. for controls, 7 lb. 13 oz. and 4 lb. 1 oz. for ewes exposed to heat during the final third and two-thirds of pregnancy respectively and, in the previous year's experiment, 1 lb. 2 oz. for those exposed throughout the pre-mating, mating and post-mating period.It is concluded that although high temperature is apparently without effect on the incidence of oestrus in sheep, it is inimical to satisfactory gestation.

Description: 1. A report is given of an experiment to investigate the extent of genotype-environment interaction in the growth rate and reproductive phenomena of certain strains of mice when kept in two food and two temperature environments. Evidence of interaction was found in both characters.2. The results are considered to be of sufficient interest to justify further work along these lines.This might either take the form of extensive studies involving many strains and environments chosen more or less at random, or in more limited investigations where the genotypes and environments are especially chosen because of marked differences.

Description: 1. Observations made on growing a series of crops in rotation over a range of static ground water-levels in a Fen peat soil are recorded.2. The crops used show differences in their reaction to ground water conditions, and the seasonal incidence of rain has an overriding influence on their performance.3. The effects of ground water-level may operate directly on the growth and development of a crop or may influence it indirectly through factors such as weed infestation, difficulties of cultivation, or the incidence of disease.

Description: After it had become evident that vitamin B12 can be considered as a part of the so-called ‘Animal Protein Factor’, several experiments with young fattening pigs have been carried out in the Netherlands. The purpose of these experiments was to gain experience as to the value of products rich in vitamin B12 for pig feeding. In these trials 312 animals were used.The results can be summarized as follows:1. Substitution to a large extent of animal protein by vegetable protein in rations containing tho same total percentage of protein resulted in a retardation of growth.2. Addition of vitamin B12 supplements to feed mixtures low in animal protein in this series of experiments generally gave better results than could be obtained without this addition. In the majority of cases, however, the results did not equal those of the groups which received rations containing the usual amount of animal protein.3. Vitamin B12 can be considered as a component of the animal protein factor, but besides this there probably exist other factors which contribute to the special value of animal protein for young pigs.4. In circumstances such as prevail in the Netherlands, little benefit can be derived for pig fattening from the use of products rich in vitamin B12.

Description: 1. The partition of riboflavin into free vitamin, flavinmononucleotide and flavin-adenine-dinucleotide in the livers and magnums of laying hens fed a diet rich in riboflavin has been determined.2. Free riboflavin in the liver amounted to 4·3% of the total vitamin, and it is concluded that this tissue does not play any part in the day-to-day metabolism of riboflavin secretion in the albumen.3. The average amount of free riboflavin in the magnum is 45% of the total vitamin. As an egg passes through the organ, the amount decreases; this decrease is equal to the amount secreted in the albumen of the egg.4. It is suggested that riboflavin accumulates in the blood while an egg is in the magnum, and in the magnum in the intervals between the passage of eggs, and that the riboflavin in the albumen is secreted at the same time as the albumen.

Description: The composition and weight of young cotton leaves at a fixed age are given for 3 years which had different rainfall before the sowing of the cotton, and for which the final yields of the cotton are also known. These yields are inversely related to the early growth and percentage composition of the crop. It is not possible to explain this, but the differences in early growth and nutrient absorption are in accord with expectation. In a year of heavy rainfall before sowing, surface soil nitrates are low, which accords with the smaller amounts of nitrogen taken up by the plants. Furthermore, there is evidence to suggest that in such a year the physical condition of the soil would be poor, which is consistent with poor growth and the low uptake of nutrients other than nitrogen.In the Sudan Gezira the yields of irrigated cotton are positively correlated with the amount of rainfall in the 6 weeks before sowing. This is not due to increased nitrate in the top foot of soil nor is it due to increased efficiency of absorption of nutrients in years of high rainfall.

Description: The partition of carotenoids and vitamin A in the colostrum of nine cows and six goats and in the milk of three cows and two goats was determined using chromatographic and spectrophotometric methods. The following were the main results:1. The content of β-carotene and vitamin A in the colostrum decreased rapidly during the first nine milkings in both the cow and the goat. The rates of decline were logarithmic. Logarithmic regressions also showed that the decreases in β-carotene were more rapid than those of vitamin A.2. The heifers secreted more vitamin A in their colostral fat than did cows on the same ration. The vitamin A content of the colostral fat of goats was greater during the first lactation than in later lactations. There was no difference in the rates of decrease of the vitamin A content of heifer and cow colostrum, but the difference between the rates of decreases of colostral vitamin A of first and later lactation goats was significant.3. The colostral fat of cows at pasture contained more vitamin A than that of cows on winter rations. There was no difference between the logarithmic rates of decrease in the two groups during the first nine milkings. The colostral fat of four goats receiving winter rations was richer in vitamin A than that of three cows treated similarly, and this superiority of the goat over the cow persisted throughout lactation.4. There was no difference between the carotene content of the colostral fat of the first and later lactation cows. The yield of fat and β-carotene of the heifers was smaller than that of the cows. Cows at pasture secreted more β-carotene in their colostrum than the cows on winter rations. The presence of β-carotene was demonstrated in goat colostrum, although mature goat milk was free from any measurable quantity of carotenoids.

Description: The extent to which early environment affects wool production of Romney sheep was studied by means of measurement of skin growth, and of fibre numbers and dimensions, of lambs reared to 52 weeks on contrasting planes of nutrition.Measurement of skin growth revealed a series of gradients which generally conformed with growth and development principles. A great degree of individuality among animals in skin growth on various regions was expressed, and it was not possible to prove that plane of nutrition caused differential skin growth among regions.An initial low plane of nutrition had a retarding effect on fleece development and fibre growth, but it could not be decided whether there was a permanent effect on fibre numbers. It seems that this is of little practical importance, since a low plane of nutrition during the major part of the follicle development phase does not appear to impair subsequent unit area production, providing immediate nutrition is good.Examination of fibre attributes, and quantitative fibre growth characteristics on various regions of the body, showed a series of orderly gradients. Large differences existed between the body regions for quantitative production per unit area and this suggests a widely differing nutrient supply of various skin regions.The importance of immediate nutrition is emphasized. It appears that permanent effects of early environment on future productivity take the form of a lesser area on which wool is produced. The efficiency of the processes, apparently, is not affected.

Description: 1. The effects of injections of oestradiol dipropionate, testosterone propionate and progesterone in immature pullets have been studied.2. Oestradiol dipropionate evokes hypertrophy of the oviduct, and increases in serum calcium and serum riboflavin.3. Testosterone propionate evokes hypertrophy and reddening of the comb and wattles, it acts synergistically with oestradiol dipropionate in evoking hypertrophy of the oviduct.4. Progesterone antagonizes the effects of oestradiol dipropionate and testosterone propionate on the growth of the oviduct.5. Progesterone and/or testosterone propionate increase the percentage of free riboflavin in the hypertrophied magnum from 18% of the total vitamin present to 35%.

Description: An experiment, designed to test different ways of using straw with fertilizers, and involving a three course rotation of crops, was carried out at Rothamsted between 1933 and 1951. The methods of analysis developed for this experiment are described in the present paper and demonstrated using yields of potatoes.Treatment effects of interest are given by the mean yields over all years and the linear regressions of yield on time. These estimates are straightforward but the evaluation of their errors is complicated by the existence of correlations due to the recurrence of treatments on the same plots. Further complications are introduced when, as frequently happens in long-term experiments, treatment effects show real variation from year to year. A method is given for estimating standard errors which include a contribution from this variation.The various relationships between yields and the uncontrolled seasonal factors can also be examined; in the present experiment there is some indication that the effects of treatments on yields of potatoes are influenced by the dates of planting.In other circumstances the analysis requires modifications, some of which are briefly considered.

Description: Study of the nutritional requirements of sugar cane on a Jamaican estate necessitated simultaneous experimentation with five manurial factors: sulphate of ammonia, superphosphate, muriate of potash, bagasse, and filter press mud. By adopting a one-third replication of a 35 factorial scheme, each factor could be tested at single and double levels for comparison with the absence of the factor.The structure and confounding system of the design adopted have been described and the method of computing the analysis of variance has been explained. Fractional replication introduces special problems of interpretation, and this experiment illustrates how they may be resolved. Each fertilizer clearly benefited the crop, and several interactions appeared; some ambiguity of meaning is an inevitable concomitant of fractional replication, so that care was needed in order to assign effects to the right causes. The most clearly marked effects were:(i) Without phosphate, nitrogen failed to produce any response; where phosphatic manuring was adequate the crop responded well to nitrogen.(ii) Superphosphate and filter press mud were practically interchangeable as sources of phosphate.(iii) Bagasse appears to act as a source of potash; the interaction of responses is not very clearly established, but little extra response to artificial potash occurred when bagasse was given.(iv) No evidence was obtained that the double level of any fertilizer was superior to the single.There was also a suggestion of a reduced superphosphate response in the presence of bagasse.If a recommendation on manuring were to be based on this experiment, it would be that a maximum of 3 cwt. sulphate of ammonia per acre be used with either 4 cwt. 18% superphosphate and 1 cwt. muriate of potash per acre or 10 tons filter press mud and 20 tons bagasse per acre. In reality, of course, no attempt ought to be made to determine a general manurial policy from results of a single year of experimentation on plant cane at one place.The experiment should be regarded rather as typical of what can be done than as a complete investigation of manurial needs.

Description: 1. The data from a survey of beef production in West Wales has been subjected to analysis by the various regression equations deduced by Callow. The calculations have elucidated the quantitative proportions of fatty tissue, muscular tissue and bone tissue as well as the calorific values of the beef carcasses derived from animals of the various grades.2. It is suggested that the method can be used as a basis to determine the controlled prices of fat cattle. The scale of prices thus obtained might encourage a better finish of the cattle and would tend to modify the seasonality of deliveries.3. The process of fattening cattle alters the proportions of fatty, muscular and bone tissues in the carcass meat, but the increase in the quantity of muscular tissue is always greater than that of the fatty tissue. At all grades, the quantity of muscular tissue in the carcass is always greater than of fatty tissue.

Description: Phosphate-potash fertilizer was drilled in bands 20 in. apart and 3 in. below the soil surface and compared with similar dressings broadcast on the surface for established crops of sainfoin. On unmanured plots yields were not reduced by cutting grooves for the fertilizer bands. Broadcasting fertilizer on the surface produced consistently more sainfoin hay than dressings placed in bands. In similar experiments on permanent grass broadcast fertilizer also gave consistently more hay than bands of fertilizer placed 10 in.apart. Intheabsence of fertilizer small decreases in yields of grass were caused by cutting grooves. The advantages of an equal supply of nutrients to all the plants in an established sward, obtained by broadcasting fertilizers, outweighs any disadvantage from confining the application to the soil surface.Two experiments on lucerne in 1950–51 compared broadcast dressings of phosphate-potash fertilizer harrowed into the seed-bed with the same quantities of fertilizer placed in one band 2 in. to the side of the seed. Side-band placement did not give better early growth than broadcasting. Broadcast fertilizer gave higher yields of hay than placed fertilizer at one centre in the first year. There were no significant differences at either centre between yields of hay given by broadcast and placed fertilizer in the second year. When the dressings were divided, half being applied at sowing-time and the remainder in the spring of the following year, slightly lower yields were obtained than from dressings applied wholly at sowing.A further experiment on lucerne was laid down in spring 1952. Superphosphate, muriate of potash and a mixture of the two fertilizers were compared both when broadcast and ploughed in and when broadcast on the seed-bed. All the dressings of broadcast fertilizer were tested in the presence and absence of a ‘starter-dose’ of superphosphate drilled directly beneath the seed. The ‘starter-dose’ gave much better early growth and higher yields of lucerne than any of the dressings of broadcast phosphate and potash. Broadcast fertilizer ploughed in tended to give higher yields at the first cutting than seedbed dressings. At the second cutting there was little difference between yields given by ploughed-in dressings and dressings broadcast on the seed-bed.There is no case for introducing special equipment to place fertilizer in bands below the surface of established swards. For establishing lucerne and other ley crops, where fertilizers may be applied at or before sowing, there are no advantages from using special drills to place the full dressing of fertilizer at a safe distance to the side of the seed. Where combine-drills are used for sowing herbage crops they should be modified to place a small quantity of superphosphate directly beneath the seed and the remainder of the fertilizer should be broadcast before sowing.

Description: 1. A rapid extraction procedure of dried and ground plant material has been used in conjunction with the Lundegårdh flame method of spectrographic analysis. The accuracy of the analysis has been estimated, and the method has been shown to be comparable with ashing and gravimetric analysis.2. The effect of fertilizer treatment on yield and on the nutrient composition of the crop has been outlined. The changes which occurred in the period1852 to 1921 have been summarized by linear regressions fitted to 10-year means.3. The recovery of potassium was estimated, and the exhaustion or accumulation of potassium was shown to be related to exchangeable potassium in the surface soil.4. Sodium and magnesium sulphates used as fertilizers were shown to increase crop yield by increasing the potassium supply to the crop. It has been shown that the extra potassium came from non-exchangeable forms.

Description: A method is suggested for the quantitative description of the genetic structure of pedigree breeds of animals. Results are given for eight breeds, showing that the number of herds controlling effective breeding policy is in all cases small.

Description: 1. It is possible for a breed of cattle to persist and to expand slowly, despite the existence of a genetic defect which prevents 50% of the calves born being used for breeding. Moreover, it is possible to exert a certain amount of selection in such a breed. The Dexter breed provides an example.2. Before 1924, about 64% of entrants to the breed were from inspected animals. Between 1924 and 1939 the breed contracted. From 1940 to 1947 the breed expanded.3. During the period of decline almost every Dexter-type female born was registered and raised. The wastage rate and age distribution of the cows are similar in Dexters to those of other breeds. There would appear to have been comparatively little breeding from Kerry types. The average registered reproductive rate of Dexter-type females was about 0·8.4. While it was not possible to examine the breed structure in the period of expansion, this was probably accomplished by lengthening the average productive life of the female, and possibly also by breeding from Kerry types.5. The possibility of exercising selection in Dexters is shown to exist. Only about 13% of the females registered are used for producing registered bulls. Of the total bull crop, only about 7% are used to produce registered females, but the bulls selected have different numbers of offspring. The use of bulls selected after progeny testing is hardly feasible in Dexters. The increased numbers of females necessary in order to produce an adequate number of heifers, renders this technique almost impossible.6. There has been little inbreeding in Dexters. This is possibly due to deliberate policy, as some of the breeders associate inbreeding with the production of monstrous calves.7. It would, therefore, appear that the damaging effect of a lethal in a breed could be overemphasized.

Description: 1. A study was made of the effect of underfeeding on the genital functions in the bull. Regular weekly collections of semen were made during (1) a 5-week pre-experimental period of normal feeding, (2) a 23-week experimental period of under-feeding, and (3) a 25-week post-experimental period of recovery.2. Although the food intake was reduced to such an extent that the bull began to lose weight at a rate of 6·5 kg. (1 stone) per week, the volume and density of semen and the motility and morphology of the spermatozoa were not significantly changed.3. In contrast to the testes, the secretory function of the male accessory glands was markedly affected by under-feeding. The concentration of fructose and citric acid in semen decreased to about 30 and 60% respectively of the original levels. During the recovery period the values for fructose and citric acid gradually returned to normal.

Description: 1. Two live-weight gain experiments using dayold chicks are described. A mash containing a basic ration with leaf protein was compared with a control mash containing the basic ration plus fish meal.2. Details of the source of the leaf protein, its extraction and chemical analysis are given.3. The composition and analyses of the mashes are recorded, together with their rate of feeding.4. The live-weight gains at fortnightly intervals are discussed and the results adjusted for sex of chicks, weight at day-old and level of protein in the mash.5. In the first experiment some of the pullets from each treatment were fed on a commercial growers' ration from 6 weeks old to maturity.6. The birds on both treatments in the two experiments were equally healthy. The mortality rates were normal. The leaf-protein chicks had deep yellow pigmentation.7. The results of the experiments are compared. In the first the leaf-protein mash was as valuable as the fish-meal mash; in the second experiment the fish-meal mash proved to be superior.8. A new method of measuring the biological value of the protein of herbage plants is suggested, using extracted protein fed to chicks or rats.9. It is concluded that a mash composed of homegrown cereals plus leaf protein with vitamin supplements, a balance of minerals and additional aminoacid if necessary, would be suitable for rearing chicks.

Description: 1. The effects of various starch and protein supplements on the digestibility of cellulose determined by the Norman-Jenkins technique and other constituents of the ration were studied in sheep.2. The addition of small amounts of maize or potato starch or flaked maize to a ration of about 1 lb. of poor hay was associated with a depression in the digestibility of (Norman-Jenkins) cellulose.3. When tested separately at varying levels, the addition of nearly pure maize protein, casein, white fishmeal, decorticated groundnut cake meal, urea or urea + DL-methionine, had no effect on the digestibility of cellulose, at any particular level of starch equivalent.4. The digestibility of nitrogenous nutrients was depressed by the addition of maize starch or flaked maize to the ration except when urea was the nitrogen supplement. The depression was even greater when potato starch was added to the ration instead of maize starch.5. The retention of nitrogen was not decreased by the addition of starch to the ration, although the digestibility of nitrogen-containing material was depressed. The retention was increased when starch was added to a ration containing casein.6. The retention of nitrogen was poor from rations containing urea and starch, but it was slightly improved by the supplementation with 1 g. DL-methionine per day.7. The addition of the various supplements had no marked effect on the digestibility of the dry matter or ‘other nutrients’ of the ration.8. It is suggested that the growth of the microorganisms digesting cellulose in the rumen is not dependent on the supplementary feed nitrogen when the substrate they are digesting contains a reasonable amount of nitrogen. This amount appears to be about 1%.9. The addition of vitamins of the B-complex to a daily ration of 1100 g. of hay did not affect the digestibility of the dry matter or nitrogencontaining substances or the retention of nitrogen by sheep.

Description: 1. In the summer of 1945 samples of the growing crop were taken from eight Broadbalk plots. On all the plots the concentrations of nutrients in all parts of the plants decreased during growth. The compositions of the roots and stems and leaves varied with fertilizer treatment at all times of the season. The nutrient composition of the ears was only slightly affected by fertilizer treatment.2. The total uptake of nutrients by the crop increased to a maximum and then decreased. The losses of potassium and magnesium from the stems and leaves were particularly large, due to translocation into the ear but there were also net losses of potassium and calcium from the whole plant.3. The changes which occurred were similar on all plots and the effect of fertilizer treatment on plant composition was always related to the effect at harvest. There was no evidence that the composition of the crop at harvest differed radically from the composition earlier in the season.

Description: The inverse relationship described in an earlier publication between phosphate response and the degree of base saturation has been confirmed with three further groups of field experiments. As an alternative to the degree of base saturation soil pH may be employed.The discrepancies sometimes found with the more acid base-unsaturated soils, between actual phosphate responses and those expected from the degree of base saturation were found to be related to the control yields. In general, the higher the control yield on a distinctly acid soil the more the percentage response to phosphate fell short of that expected, and vice versa. By forming multiple regressions of percentage phosphate response on both control yield and the percentage saturation of the B.E.C. a more accurate assessment of phosphate response is possible than by using the simple regression of response on the percentage saturation of the B.E.C. A measurable soil characteristic that could be used in the multiple regressions instead of the control yield was not found.Very significant and inverse relationships were established between percentage phosphate response and the amount of water-soluble or citric acidsoluble silica. These silica contents were also found to be significantly and directly related to the percentage saturation of the B.E.C. It appears that measurements of pH, silica and base saturation function similarly in classifying the soils, distinguishing between the almost neutral soils retaining phosphate in an available form associated with exchangeable bases, acid soils with relatively unavailable phosphate associated with iron and aluminium compounds, and soils intermediate between these.

Description: 1. Semen was collected from bulls by means of the electro-ejaculation method developed by Thibault et al. (1948).2. A copious sperm-free fraction of the ejaculate, produced in the early phase of stimulation, was examined for its chemical composition.3. This secretion was found to have a low protein content, but its chloride concentration was higher than in the sperm-containing fractions of the ejaculate. Fructose and citric acid occurred in very low concentrations, and 5-nucleotidase was absent in the pre-sperm secretion. This indicates clearly that the secretion does not originate either in the seminal vesicles or in the ampullar glands; it is probable that it represents a discharge from the urethral glands.4. The effect of the pre-sperm ejaculate fraction upon bull sperm fructolysis and motility was examined; both were unaffected by a considerable excess of this secretion.5. The chemical composition of the pre-sperm secretion makes it unlikely that under physiological conditions it could play a role in the nutrition of the spermatozoa; presumably, its chief function is the clearing of the urethral passage prior to the descent of the semen proper.

Description: The normal course of mammary development has been briefly described, in sheep from 2 months of foetal age to 4 months after birth; and in dairy cattle from the 3-month foetus to calves 6 months old. Observations were also made on a series of udders from ewes during their first pregnancy. A small group of beef calves and a number of freemartins of various ages were also examined.Development was found to be closely similar in the two species, and in both, sex differences were marked.Experimentally it was found that in males of either species castration at birth had little effect on mammary growth, while prolonged treatment with oestrogen gave rise to enlarged teats, dilated cisterns and ducts, and to a certain amount of secretion. Little gland tissue was formed in oestrogen-treated males, and there was no increase in the spreading of mammary tissue from the neighbourhood of the teat.Females of the two species showed a striking difference in their response to experimental treatment. In sheep, removal of the ovaries at birth had no apparent effect on mammary development up to 4 months, while treatment with oestrogen stimulated gland formation in both spayed and intact lambs and also restricted the normal spread of mammary tissue into the udder. In cattle, on the other hand, heifers spayed at birth showed almost complete cessation of mammary development, while implants of oestrogen, in addition to inducing gland formation, promoted the spreading of tissue into the udder pad of the spayed animal.Udder development of freemartins appeared to be similar to that of normal heifers from 5 months foetal age to about a month after birth, but thereafter was more like that of a spayed animal. Removal of the abnormal gonads shortly after birth had no effect, while oestrogen treatment induced development of teats, ducts and glands exactly as in a normal heifer.Comparing small numbers of calves of the two types, it was found that heifers of the beef breed in general showed slightly poorer mammary development than dairy heifers that had been treated in the same way, with more connective tissue and numerous leucocytes in the mammary zone.

Description: In experiments on peas, beans, carrots, kale, beetroot and spinach appropriate dressings of fertilizers placed in one band 3 in. below the soil surface and 2 in. to the side of the seed did not damage germination. Peas and beans are likely to be injured when even small dressings of soluble fertilizers are drilled in contact with or below the seed.In sixteen experiments on peas and nineteen experiments on beans in 1949–51 broadcast fertilizer gave small increases in yield of beans and peas in dry years and larger increases in wet years. In about one-quarter of all the experiments fertilizer broadcast early and either ploughed or cultivated deeply into the soils gave significantly higher yields than late dressings worked into the seed-beds. In roughly one-third of all the experiments on each crop there were significant increases in yield from placing as compared with broadcasting fertilizer. The average extra yields produced by placing fertilizer were 1·8 cwt. per acre of threshed peas, 9·3 cwt. per acre of green peas, 1·0 cwt. per acre of winter beans and 1·3 cwt. per acre of spring beans. For spring-sown crops extra yields from placement were greater than the increases from broadcasting fertilizer. There was little advantage from splitting the fertilizer dressing, broadcasting half and placing the remainder beside the seed.In most experiments on peas and beans, yields given by a single dressing of placed fertilizer were equal to, or greater than, the yields given by double dressings of broadcast fertilizer. When placed in the correct position quite small quantities of fertilizer are sufficient for maximum yields of such crops. The use of suitable drills should be profitable to farmers growing appreciable acreages of peas, beans and rapidly maturing horticultural crops. Where special placement drills are not available, fertilizers for peas and beans should be broadcast before cultivating to prepare the seed-bed and, when possible, the dressings should be ploughed-in. There was no advantage from placing fertilizer at the side of the seed for carrots, kale or beet. Placed fertilizer gave a higher yield of spinach than broadcast fertilizer.Placing fertilizer at the side and below the level of the seed is likely to give better yields than broadcast fertilizer for crops having short growing seasons or poorly developed roots and when broadcast nutrients are immobilized in the surface soil by drought.

Description: Soil was maintained in a moist condition with as complete aeration as possible, for periods up to 89 weeks, either alone or after the addition of straw, ground-up mustard plants, ground-up tare plants, or ammonium sulphate. The nitrogen which existed as nitrate, ammonia, or other materials soluble in cold water, as compounds only soluble in hot water, or as substances only soluble in dilute HCl, was determined at intervals during this period. In general, little change took place after 11 weeks apart from a very slow and very slight increase in the nitrate produced, except after the addition of straw. Ammonia was reduced to a trace in all cases. The whole of the nitrogen soluble in cold water became converted into nitrate or ammonia in less than 11 weeks, except in the case of the admixture with straw. With straw there was far less accumulation of nitrate than when no addition was made, and this prevention of the formation of nitrate continued to the end of the experiment (89 weeks). The less soluble nitrogenous material (i.e. that only soluble in hot water or in HCl) was hardly affected by the long incubation.The added nitrogen was entirely recovered after the end of the experiment, except where ammonium sulphate was used. In this case there was an apparent disappearance of 30% of the added nitrogen.

Description: Cytological stvidies did not show any detectable structural changes which could be related to the spermhead deformity in a series of sterile bulls described by Hancock. The deformity according to Hancock consists of a deeply stained (in iron haematoxylin) area placed askew at the apex of the spermhead.In spermateleosis it is connected with persistence of the shallow apical groove of the nuclear membrane observed only in earlier stages of development in normal cases. There is also a formation of vacuoles in the developing spermheads in the region of the apex and of the equatorial belt. The apex of the abnormal spermhead treated with Feulgen reagent appears to be cut off askew.Formation of vacuoles in the developing spermheads may be related to some unknown changes in the nucleic acid metabolism of the spermhead. The absence of any chromosomal aberration, whether of quantitative or structural nature, may lead to the conclusion that the changes observed are due to a gene mutation.

Description: Analyses of grass samples from seventeen fertilizer trials on acid soil showed that both the percentage phosphate in the grass and the amount of phosphate removed by the crop were significantly and directly related to the percentage saturation of the b.e.c. of the soil. The amount of acid-soluble phosphate by difference (Table 1, A — B) was also significantly and directly related to the percentage phosphate in the grass but not to the amount taken up by the crop. The amounts of exchangeable bases, exchangeable calcium and acid-soluble, adsorbed and watersoluble forms of phosphate showed no significant relationships with phosphate uptake and percentage phosphate in the grass.The percentage saturation of the b.e.c. was found to be, on the average, about five times as effective a contributory factor to the percentage phosphate in the grass as the amount of acid-soluble phosphate by difference. The results confirm previous work, which indicated that in acid soils the main form of available phosphate is that associated with the exchangeable bases the effective presence of which is governed by the percentage saturation of the b.e.c. It is considered that phosphate availability and response in acid soils are best assessed by considering the percentage saturation of the b.e.c. rather than the amounts of some form or forms of phosphate in the soil.The grass analyses also showed that when the amount of phosphorus (P) hi the dry grass exceeds 0·33% no response to phosphate is to be expected. When the percentage in the grass is less than 0·23% responses of 10% or more are likely.

Description: 1. Further studies were carried out during 1950 on the effects of different ground water-levels upon the productivity and composition of Italian ryegrass grown on a calcareous light peat soil. The season was an unusually wet one, in contrast with the dry season experienced in 1949.2. Seven successive cuts were taken during the season from each of two crops of ryegrass, one following a crop of marrow-stem kale, and the other a crop of celery. Different amounts of a general compound fertilizer had been applied.3. Generally, the findings confirmed those of the previous year's investigation. High ground waterlevel (approximately 18 in. below ground surface) had a deleterious effect upon the yield and quality of ryegrass as reflected by its protein content, compared with the medium and low water-levels (23 and 30 in. below ground surface, respectively).4. The high water-level also had a depressing effect upon the percentage of potassium and magnesium in the grass, but had no consistent effect upon calcium and phosphorus. The silica content rose steadily in all cases as the season advanced, as occurred in the previous year.5. Residual manuring effects were well marked in the crop following celery. The total yields of dry matter from the medium and low water-levels considerably exceeded those of similar plots following kale, and the protein contents were also appreciably higher. This demonstrates the advantages of a high soil nutrient status, under conditions of suitable water-levels, for a crop of fenland grass.6. A high water-level inhibited growth and quality, irrespective of the nutrient status of the soil.

Description: 1. The relationship of semen age to conception rate was studied at two artificial-insemination centres and a subcentre of one of these. Data relating to 50,213 first inseminations were included in the analysis.2. It is shown that external conditions can affect the rate of decrease of conception rate with semen age.3. Records giving c.r.'s for each day of semen age may reveal centre differences that cannot be detected in records giving mean c.r.'s only.4. Information may be lost if data are grouped by months rather than recorded by collections.5. The rate of decrease should not be used for comparing centres until the various factors affecting it (e.g. breed differences) are more fully understood. Further investigations should not be limited to one centre.

Description: 1. The availability of the calcium in three common herbs, viz. narrow-leaved plantain, chicory and burnet, has been investigated using the rat as the experimental animal.2. Parallel methods used for the determination of calcium balance involved (a) the analysis of feed, faeces and urine, and (b) carcass analysis.3. The availability of the calcium, while high in all three species, was in the order plantain, chicory and burnet. All differences between means were significant at P = 0·05.4. There was shown to be some evidence of inverse relationships between fibre content and calcium availability, and between oxalic acid content and calcium availability.

Description: 1. The effect on cow health of galactopoietic stimulation with thyroactive materials was determined from a statistical study of the results of a large field experiment involving 2000 cows over a 3-year period.2. The same experimental procedure was followed on thirty-seven farms scattered over England, Scotland and Wales. This procedure was planned to ensure that half the cows in each herd would receive a course of treatment with iodinated casein or thyroxine, and that the other half would constitute a suitable set of controls. Cows that remained in the herds received second and third treatments in successive lactations.3. The galactopoietic stimulation was started at a fixed interval after calving, irrespective of the season of the year.4. The use of the thyroactive materials in successive lactations did not have any serious adverse effects on the health of cows. The effect on productivity was less than had been expected, since the increase in milk yield resulting during the period of hormonal treatment was often largely or completely negatived by a shortening of the lactation period.5. The incidence of disease was somewhat greater in the treated than the control group, the principal contribution to this difference being from the diseases described as digestive disorders. There were some other differences of lesser significance.6. The rate of disposal of treated and control groups was almost identical.7. There were no adverse effects on the reproductive life of treated cows; factors studied were the efficiency of coitus, interval between parturitions, length of gestation and incidence of abnormalities at parturition.

Description: The materials and methods have been described in the first paper of this series (Glover, 1953). All experiments were of 33 factorial design (Yates, 1937) involving three different levels of supply of nitrogen, phosphorus and potassium.The results of the measurements are shown graphically in Figs. 1–4 inclusive. Because of the limits set by reproduction of Figs. 1 and 2 it is impossible to show minor variations due to different treatments. Where the curves of uptake run together one broad line is used to denote this. Deviations from this line are shown where they occur. Superimposed on the figures are lines denoting the length of the tasselling and silking periods. Thus a line covering a period of, say, 10 days and bearing the symbol T shows that tasselling in the particular series was completed in that period, and the first tassel was set at the date corresponding to the start of the line.

Description: 1. The use of the technique of gas-partition chromatography in the investigation of the formation of volatile acids in minced grass/water slurries is discussed.2. Slurries kept anaerobically at 17, 37 and 62° for 13 weeks have been examined, and the amounts of the different volatile acids formed have been estimated. It has been noted that butyric acid forms most readily in the slurry at 37°, while in aerated slurries at 17°, the formation of volatile fatty acids is more speedy than under anaerobic conditions.3. Only acetic, propionic and butyric acids have been noted so far, and the highest concentrations of the acids observed in any slurry were 5, 1·25 and 4% respectively.