ALBERT

Description: SummaryEleven single-rearing and 14 twin-rearing Greyface (Border-Leicester × Scottish Blackface) ewes which had previously been individually fed indoors on three nutritional treatments (treatment 1, adequately nourished; treatment 2, moderately undernourished; treatment 3, severely undernourished) during the final 6 weeks of pregnancy, were subsequently grazed with eight non-lactating Greyface ewes on a ryegrass–white clover pasture for the first 14 weeks of lactation.Herbage organic matter (OM) intakes and milk yields of ewes were measured weekly and the herbage OM intakes of lambs from week 7 of lactation.Mean daily OM intakes were 36·6 (± 1·09), 38·9 (± 0·99) and 26·4 (± 0·93) g OM/kg body-weight for single- and twin-rearing, and non-lactating ewes respectively. Prepartum nutrition had no effect on intake. Maximum intakes were achieved in week 5 for twin-rearing ewes (53 g OM/kg) and week 4 for single and non-lactating ewes (54 and 38 g OM/kg respectively).Mean daily weight gains over the period for single-, twin-rearing and non-lactating ewes were 89 (±22·2), 73 (±16·1) and 182 (±22·5)g respectively. There were no differences due to prepartum treatment.There were significant differences (P 〈 0·05) in milk production between singleand twin-rearing ewes in the first 5 weeks of lactation. Twin-rearing ewes of prepartum treatment 1 produced consistently more milk in weeks 2, 3 and 4 of lactation, whereas ewes from treatment 3 tended to produce more milk than ewes from the other treatment groups thereafter.Milk intakes of single lambs were always significantly greater than individual twin lambs, and single lambs ate significantly less grass during the herbage OM intake measurement period from week 7; their growth rates up to week 7 were also significantly greater.No differences in the intake or growth rate of lambs could be attributed to the prepartum nutritional treatment of their dams.Ewe maintenance requirements during lactation were estimated to be 242 (± 35·1) kJ ME/kg body weight/day; the efficiency with which ME was used for milk production to be 59%; and the efficiency with which ME was used for body-weight gain, 53%.Lamb maintenance requirements were estimated to be 427 (± 143) kJ ME/kg W in weeks 1 and 2 of lactation and 287 (± 44·2) kJ/kg from week 7. Efficiency of utilization of energy for body-weight gain in each period was estimated to be 71 and 80% respectively.

Description: SummaryA radiography unit was developed with which two technicians and two assistants were able to diagnose number of foetuses in 400–600 ewes per day on farms. Diagnoses made between 100 and 120 days of gestation in flocks where weekly mating records were made were 95–98% accurate as judged by lambing records. In most flocks more than 90% of twin pregnancies were correctly diagnosed. Agreement between diagnoses and lambing records was reduced when weekly mating records were not available. The radiographic examination had no detrimental effects on ewes or lambs.

Description: SUMMARYA model is derived that relates yield to levels of applied fertilizer in terms of parameters that have direct physical meaning. N8, P8, and K8 define the contribution of the soil to the supply of nitrogen, phosphorus and potassium for plant growth; BN, BP and BK define the responses to nitrogen, phosphorus and potassium fertilizer at low nutrient levels and aN is the level of nitrogen required to raise the osmotic pressure sufficiently to prevent growth.To test the model, field experiments were carried out on French beans and summer cabbage in which 125 different combinations of levels of nitrogen, phosphate and potassium fertilizers were applied. The yield data from each block of each experiment fitted the model very well. Fitted values differed from block to block but these differences could be attributed to the fact that for each block equally good fits were often obtained with widely differing parameter values. Estimates of N8 were made from chemical analysis of the (NH4 + NO3) — N of soil samples from the field plots, and P8, and K8 from chemical studies of the adsorption of phosphate and potassium on untreated soil. They were in substantial agreement with the average values obtained by the entirely different procedure of fitting the model to the yield data. Also estimated values for BN, BP and BK and aN from other chemical studies were consistent with those obtained by model fitting.It is concluded that although the theory has limitations it is broadly in accord with the results of the detailed field experiments.

Description: SummaryRed blood cell electrolyte levels and haemoglobin types have been determined in flocks of Peppin Merino sheep genetically different for clean fleece weight and crimp frequency. The flocks selected for high clean fleece weight or low crimp frequency had significantly higher mean erythrocyte potassium levels than did those flocks selected for low clean fleece weight or high crimp frequency, this difference was apparent in both haemoglobin AB and BB types. Erythrocyte potassium concentration was not correlated with either clean fleece weight or crimp frequency within flocks. The high clean fleece weight flock had a significantly higher gene frequency for high potassium than did the low clean fleece weight flock, while the high crimp frequency flock had a lower haemoglobin B gene frequency than the low crimp frequency flock.

Description: SUMMARYIn summer 1977 a random survey was made of 2250 fields on 1153 farms selected throughout the United Kingdom. Wild oat, Avena spp., was surveyed in all countries; black grass, Alopecurus myosuroides, was surveyed in England and Wales; and couch grass, including Agropyron repens and other perennial grasses, in Scotland and N. Ireland.Wild oat was reported by farmers on 95% of farms in England, 34% in Wales, 65% in Scotland and 30% in N. Ireland; the areas of infestation in the different countries were 67, 13, 37 and 16% respectively. The majority of wild oat was A.fatua. Only 6% of the cereal area of U.K., including sprayed and unsprayed fields, contained more than one wild oat seed head/m2 (10000/ha), the majority had less than one/20 m2. Black grass was reported on 50% of farms in England (22% of cereal area) mainly in East and South, and on 2% of farms in Wales. Couch grass occurred on 92% of farms in Scotland and 68% in N. Ireland: areas of infestation were 88 and 67% respectively. Most of the infestations of all three weeds had been present for longer than 5 years.Most farmers intended to eliminate or reduce wild oat and few proposed to hold the weed at its present level or do nothing. Herbicides were used against wild oat on approximately half of the infested area in England and Wales, with proportionately more use in Wales and much less in Scotland and N. Ireland. A third of the black grass infested area of England was treated with a herbicide. There was little spraying against couch grass in Scotland and N. Ireland. Details of dose, time of application and mixing of chemicals were obtained. Wild oat was subsequently found on most of the area treated against this weed, similar observations were made of black grass and couch grass. Most farmers considered herbicide performance good or excellent and those in East and South England believed wild oat to be decreasing as a problem; farmers elsewhere thought the problem to be increasing.Hand pulling of wild oat (roguing) had occurred on only one tenth of the infested area but a greater area was intended to be rogued after the survey visit. Much of the land that had been rogued was found subsequently to contain few wild oats.The survey provided information on associations between weed presence, soil type and cropping system, the types of herbicide used and farmers’ impressions of their performance. Comparisons are made with previous surveys in 1972, and information on the disposal of the 1976 crop of straw and on types of cultivation used in different regions is provided. The implications of the results are discussed.

Description: SummaryBy systematic sampling (including the drilling of orientated cores) new data are presented on the chemistry, petrography, mineralogy, K/Ar isotopic age and remanent magnetism of the Wolf Rock, Cornwall. The overall homogeneity of the Rock is confirmed as a fine-grained fluxioned microporphyritic phonolite. Major joints strike NNW–SSE and NNE–SSW and there is a pronounced floor jointing. New whole-rock and probe analyses of the constituent minerals are given. Nosean, previously recorded, is found to be replaced by analcime, cancrinite and other minerals. K–Ar determinations on nepheline and K-feldspar give mean ages of 112±2, and 130±6 Ma respectively. The mean pole position of 70° N, 6° E, suggests that the 130 Ma pole for stable Europe may have been somewhat closer to Europe than previously supposed. The significance of this Lower Cretaceous magmatism in the context of Mesozoic volcanism in Southern England and European alkaline provinces is discussed.

Description: SummaryThe Comores Archipelago comprises four principal islands, lying in a WNW–ESE line at the northern end of the Mozambique Channel. The Islands are almost entirely volcanic and show a simple age progression from Grande Comore, with its active shield volcano Kharthala (2650m), east-south-eastwards through Mohéli and Anjouan, which are quite deeply dissected, to Mayotte, which is in an advanced stage of erosion and subsidence, and is encircled by a barrier reef. There is also evidence of minor volcanic rejuvenation in relatively recent times in Mayotte, and perhaps Anjouan and Mohéli. The lavas of Kharthala, and the neighbouring extinct shield volcano (Massif de la Grille) on Grande Comore are all basaltic, ranging from oceanitic and ankaramitic to aphyric types. Numerous tuff cones occur, especially on the flanks of Massif de la Grille. Basaltic lavas, similar to those of Grande Comore, form the bulk of the dissected volcanic shields of Mohéli and Anjouan, but there is also evidence of differentiation towards alkalic under-saturated end products, both as lavas and as intrusive bodies. Lherzolitic and gabbroic nodules are locally abundant on each of the islands, while xenoliths of sandstone and quartzite have been found on the three westernmost islands. Petrochemical data are presented for a considerable variety of Comores rocks, and the volcanic activity is discussed in terms of the major structural features of the Madagascar-Mozambique region.

Description: The following list of dates are selected from geologic and archaeologic samples measured in early 1975. The technique employed is liquid scintillation counting of wholly synthesized benzene as described by Noakes et al (1965) and discussed in R, v 16, p 402–408. Errors are reported as one standard deviation.

Description: The radiocarbon dating facility is part of the UM Geochronology laboratory housed in the Department of Geology, University of Miami, Main Campus. The laboratory was established to carry out and support research in Pleistocene marine geology, particularly in the Caribbean, and to act as a specialized teaching facility of geochronologic research using radiometric age dating techniques.

Description: The following list of dates are selected from geologic and archaeologic samples measured in late 1974. The technique employed is liquid scintillation counting of wholly synthesized benzene as described in (R, v 16, p 402–408). Errors are reported as one standard deviation. Sample descriptions and comments were written in collaboration with collectors and submitters.