bluuebunny/crossref_metadata_2025_split huggingface dataset:
The ‘teat order’ of suckling pigs: 3. Relation to competition within litters
Authors: Fraser D. , Thompson B. K. , Ferguson D. K. , Darroch R. L. 
Published: March 2009

SummaryPiglets in litters, paired according to farrowing date, were redistributed during the first day after birth according to two schemes. In scheme AC–BD, one sow of the pair received the heaviest and the third heaviest quarters of the combined litters (based on weight post partum), while the other sow received the second heaviest and the lightest quarters. In scheme AB–CD, one sow received the heavier half, and the other the lighter half of the piglets. After 3 weeks under scheme AB–CD, the weight difference between the second and third quarters had become reversed, while under scheme AC–BD the difference was preserved. There was no evidence of a corresponding interaction in the selection of anterior or posterior teats. The rank correlation of the piglets' initial weight and suckling position was low for most sows. No marked differences were observed between fostered and unfostered piglets in the weight measures or suckling position. It is concluded that the growth of the piglets was influenced by the relative size of their litter-mates after redistribution, but that little of the effect could be explained by competition for the anterior teats.
Gluconeogenesis in foetal, suckling and weaned lambs: the effect of glucagon
Authors: Savan P. M. J. , Jeacock Marjorie K. , Shepherd D. A. L. 
Published: March 2009

SUMMARYThe effect of glucagon on the rate of glucose production in the presence of alanine, of lactate and of propionate has been studied in isolated perfused livers obtained from foetal, suckling and weaned lambs.Glucose utilization occurred in foetal livers in the absence of glucagon whereas addition of glucagon resulted in a net production of glucose from the three substrates. In livers from suckling and weaned lambs addition of glucagon was not essential for glucose production to occur and the stimulation of gluconeogenesis by added glucagon was less evident in the older lambs. The effect of glucagon was not dependent on changes in the rate of substrate uptake.It is concluded that gluconeogenesis will be induced by glucagon in foetal lambs when their mothers are severely undernourished, and that placentally derived lactate could contribute up to 90% of the glucose synthesized.
The physiological basis for mixing varieties and seed ‘ages’ in potato crops
Authors: Burstall Lindsay , Harris P. M. 
Published: March 2009

SUMMARYThree techniques designed to increase radiation interception, and thus yield, in potato crops by extending the duration of the crop canopy were investigated over a period of 2 years. These were: mixing contrasting varieties; mixing seed tubers of contrasting physiological ages of the same variety, and early planting with protection from frost.The first technique was partially successful; increases in total tuber fresh weight of the mixture over either of its components grown alone were recorded but the mixtures generally did not have any advantage in terms of ware yield (40–80 mm tubers) and total yield advantages were found in only 1 year. The second technique was unsuccessful in both years with all seven varieties tested. The third technique was successful with the long-lived variety Cara; large advantages both in ware yield and total tuber dry weight yield were obtained under two irrigation regimes. No advantages from early planting were obtained with the shorter-lived variety King Edward.Radiation interception was estimated for all treatments by means of relationships established between intercepted radiation and percentage ground cover. None of the three techniques increased radiation interception; the yield advantages obtained could be ascribed either to an increase in the proportion of assimilates allocated to tubers or possibly to improvements in the efficiency of use of intercepted radiation.
Protein studies on maize silage as a basal ration for dairy cows
Authors: Phipps R. H. , Weller R. F. , Smith T. , Fulford Rosemary J. 
Published: March 2009

SUMMARYIn Expt 1 40 lactating British Friesians, 20 cows and 20 heifers, were used to study the effect of crude protein (CP) content of the whole ration on milk yield, milk composition and live-weight change when maize silage was fed as the basal ration. There were four treatments with five cows and five heifers on each. During lactation weeks 4–12 the cows on treatments 1, 2, 3 and 4 all received 7 kg maize silage dry matter (D.m.) plus 8 kg D.m./day of a concentrate containing either 14, 18, 22 or 24% CP, respectively; heifers received 1 kg/day less of both silage and concentrate. This produced whole-ration CP contents of 11·7, 13·9, 16.·0 and 17·1%. In the subsequent lactation weeks 13–20 silage feeding was increased to 9 kg D.m./cow/day and concentrate feeding decreased to 5 kg D.m./cow/day. Heifers again received 1 kg/day less of both silage and concentrate. This decreased whole-ration CP contents to 10·5, 11·7, 12·9 and 13·4%.During lactation weeks 4–12 and 13–20, with the exception of milk fat content in weeks 13–20, there were significant linear effects of whole-ration CP content on milk yield, milk fat, protein, lactose and total solids. There were no significant curvilinear relationships. Thus, despite the fact that the highest numerical values were generally recorded for the animals on treatment 3, the results indicate that a whole-ration CP content of at least 17·1 and 13·4% are required in early and mid-lactation respectively.In Expt 2 the loss of D.m., acid-detergent fibre and nitrogen from maize silage suspended in nylon bags in the rumen was measured. Compared with feeding either a low or high protein supplement, losses were greater for silage fed alone. If it is accepted that nitrogen loss can be approximated to protein degradability, then the value for maize silage was between 0·6 and 0·7. Using the same technique in Expt 3, comparable nitrogen losses for fish meal, decorticated groundnut meal and soya-bean meal were 0·3, 0·9 and 0·9, respectively, after 24 h incubation.
Evaluating selected forage legumes for livestock and crop production in the subhumid zone of Nigeria
Authors: Tarawali S. A. 
Published: March 2009

SummaryA programme of forage legume evaluation was developed at the International Livestock Centre for Africa's (ILCA) subhumid research site in Nigeria from 1985 onwards. Evaluation included monitoring herbage and seed yields, incidence of diseases/pests, regeneration ability and persistence for three growing seasons. This was followed by an in situ bioassay to determine the direct effect of the sown legumes on maize (Zea mays L.) production in the absence of added nitrogen.The results for selected accessions from introductions received in 1987 and 1988 are presented. Stylosanthes guianensis CIAT184 (ILCA164) and ILCA15557 and Aeschynomene histrix ILCA 12463 were promising both in terms of biomass production (up to 9·4, 3·4 and 9·6 t/ha respectively) and quality (all had crude protein values of 11% or more), and in terms of beneficial effects for maize production (all plots gave significantly more grain than those with no legume, reaching over 3 t/ha for maize grown on plots after S. guianensis ILCA15557). The use of such appropriate forage legumes to enhance both livestock and crop production in a sustainable farming system is recommended.
Effects of various hand-weeding programmes on yield and components of yield of sweet potato (Ipomoea batatas) grown in the tropical lowlands of Papua New Guinea
Authors: Levett M. P. 
Published: March 2009

SUMMARYThe effects of weed competition, harvest date and cultivar on sweet potato (Ipomoea batatas(L.) Lam.) yield and components of yield were investigated in three factorial experiments planted during the wet seasons of 1984 (Expt 1) and 1986 (Expts 2 and 3) in the tropical lowlands In Expts 1 and 2, the commencement of regular hand-weeding (every 14 days) was delayed for varying lengths of time following planting. In Expt 3, the duration of hand-weeding from planting onwards was varied. The main competing weed species following planting were Cyperus rotundus, C. brevifolius, Euphorbia geniculata and Portulaca oleracea. After canopy closure, E. hirta, Imperata cylindrica, Eleusine indica, Sida rhombifolia, Mollugo pentaphylla and Mimosa invisa were the predominant weeds to emerge and persist. Cultivars differed in their sensitivity to weed competition. In L431 both mean marketable root tuber weight and number of tubers/plant were severely reduced. However, in L44, tuber number was more sensitive than tuber weight: marketable tuber weight was significantly reduced only by prolonged weed competition (no weeding until 56 days after planting (DAP)). In Expts 1 and 2, delaying the commencement of weeding beyond 14 DAP significantly decreased vine weight, total yield and mean number of tubers/plant. In Expt 3, prolonging regular weeding until 14 DAP and longer significantly increased total and marketable tuber yield and mean number of tubers/plant.Effects of weed competition in the early part of the season during the first 28–42 DAP substantially reduced crop production in the later part of the growth cycle (after 110 DAP). This was probably due to a partial suppression of vine growth early on, which reduced tuberous root initiation and thus limited the number of root tubers that could develop in the later stages of crop growth. Hand-weeding during the period 28–42 DAP also appeared to have a detrimental effect on tuber initiation as a result of mechanical root disturbance at this sensitive period of root differentiation. There was also a trend towards lower yields when the crop was regularly hand-weeded after 56 DAP, probably due to disturbance of the vine canopy.The critical period for weed competition commenced at or before 14 DAP, possibly as early as 7 DAP, and did not continue beyond 56 DAP. In order to avoid weed competition and the detrimental mechanical effects of hand-weeding, an optimum hand-weeding programme for sweet potato in the tropical lowlands of will probably involve (i) keeping the crop weedfree for the first 14–21 DAP; (ii) no crop disturbance during the period of maximum tuberous root initiation (from c. 21–28 DAP until 42–56 DAP); (iii) clean weeding at c. 56 DAP; and (iv) minimal or no weeding after 56 DAP. Weeding during the period 7–14 DAP is particularly important.
Rate of production of protozoa in the rumen and the flow of protozoal nitrogen to the duodenum in sheep and cattle given a pelleted diet of lucerne hay and barley
Authors: Punia B. S. , Leibholz J. , Faichney G. J. 
Published: March 2009

SUMMARYTwo crossbred wethers (c. 45 kg) and two Hereford heifers (c. 215 kg) were fitted with permanent cannulas in the rumen and abomasum and given a diet of lucerne hay and barley (60:40). Organic matter (OM) intakes were 0·67 kg/day for sheep and 3·14 kg/day for cattle.The mean numbers of protozoa in the rumen fluid were 9·3 × 105/ml for sheep and 7·4 × 105/ml for cattle. 14C-labelled protozoa were prepared by incubating rumen fluid in vitro with [14C]methyl choline and then isolating them by sedimentation and differential centrifugation. The labelled protozoa were returned to the rumen of each of the donor animals in a single injection. The specific radioactivity in mixed protozoa isolated from the rumen was measured for 3 days. The protozoal pool size was 10 and 12 g N in the sheep and 64 and 44 g N in the cattle. Protozoal N contributed, on average, 48% of the total N in the rumen.Production of protozoal N in the rumen was 9·5 and 11·2 g/day for the sheep and 49·5 and 38·6 g/day for the cattle. The flow of protozoal N from the abomasum was calculated to be 1·6 and 2·9 g/day for sheep and 17·3 and 13·3 g/day for cattle. Thus, on average, 79% of the protozoal N was recycled within the rumen of the sheep and 65% within the rumen of the cattle. Protozoal N made up 11–20% of total N flow from the abomasum. The turnover times of 14C-labelled protozoa injected into the rumen of the sheep and the cattle were similar (26·2 and 26·8 h for sheep; 30·8 and 27·5 h for cattle) and were similar to those for protozoa isolated from the rumen of sheep after direct intraruminal injection of [14C]methyl choline (28 and 36 h).
Intravaginal oestradiol-progestagen treatments in the induction of early breeding in sheep
Authors: Gordon I. 
Published: March 2009

SUMMARYSix hundred and sixty-two sheep in twenty-two farm flocks were treated in June/July (period of late anoestrus) with intravaginal sponges impregnated with 30 mg ‘Cronolone’ (9α-fluoro-11β-hydroxy-17α-acetoxy-progesterone; G. D. Searle) or ‘Cronolone’ plus 400 mg progesterone and incorporating doses of 0-800 μg oestradiol-17β. Treatment was for 12 days; a single dose of 500 i.u. PMS (Burrough's Wellcome) was injected at pessary withdrawal. Seventy rams were joined to breed the ewes at first and second heats.Oestradiol treatment resulted in a significantly higher incidence of sponge loss, a lower mating response, a lower conception rate and a lower number of lambs/conception. There was also a tendency for onset of oestrus to be delayed. Such effects were confined to first services and were much less evident in sheep receiving doses of 50 μg oestradiol or below. Data indicate that an intravaginal treatment for the induction of early breeding should consist of progestagen alone rather than progestagen in combination with oestradiol. The addition of 400 mg progesterone to the ‘Cronolone’ sponges appeared to reduce the adverse oestrogenic effects. Sheep treated with ‘Cronolone’/progesterone pessaries in the absence of oestradiol showed a mating response of 97%, a conception rate of 64% and 1·7 lambs/conception at the controlled oestrus.
Behaviour of ewes during parturition
Authors: Sharafeldin M. A. , Ragab M. T. , Kandeel A. A. 
Published: March 2009

SUMMARYA number of 237 Barki ewes of 2, 3, 4 and 6 years of age and weighing 25–45 kg were put under close observation so as to study the subjective and objective aspects of their behaviour during parturition.During the choice and preparation of the parturition site ingestive behaviour ceased and an investigatory behaviour took place using the visual and olfactory senses. Ewes showed preference for the less illuminated and less disturbed places. They pawed the chosen spots with their hooves so as to prepare them for parturition. The parturient behaviour was characterized by signs of uneasiness and of pain, which increased gradually until the lamb&apos;s expulsion.The overall average pre-partum time of labour was 46·1 plusmn; 1·6 min. The 2-year-old ewes took longer to give birth than older ones. The pre-partum labour was not significantly affected by body weights of ewes. The overall average duration of the post-partum labour was 143·27 min. Age and weight of ewes had no significant effect on the duration of the post-partum labour. Births were not evenly distributed over the period of observation.
The effect of Water Loading on urea metablism in Cattle
Authors: Vercoe J. E. 
Published: March 2009

SUMMARYSteers fed low nitrogen diets were infused intraruininally with water.Increasing the water load increased the urine volume and urinary urea excretion and depressed the plasma urea level.The effect of intraruminal water loading was studied in association with intravenous urea loading of 25 and 65 g N/day. When 25 g N/day as urea was infused intravenously, water loading did not significantly increase the urinary urea excretion but the plasma urea level was depressed. At 65 g N/day water loading increased the urinary urea excretion and decreased the plasma urea level.Significantly different relations between plasma urea and urea load existed for the ad lib. water and the water-loaded treatments but the relation between rumen ammonia level and plasma urea level was not affected by the water loading.The results are discussed with reference to the recycling of urea.
Dry matter production of oilseed rape (Brassica napus) with special reference to the root system
Authors: Kjellström C. G. , Kirchmann H. 
Published: March 2009

SUMMARYAt the research farm of the Swedish University of Agricultural Sciences, Uppsala, above- and belowground production and changes with time in root length, mean root radius and root surface area of spring oilseed rape were studied during the growing seasons 1987 and 1990. In both years, the highest root growth rate was recorded during the stem elongation phase, and the highest shoot growth rate during flowering. The root: shoot ratio decreased throughout the whole period of root sampling, from 0·64 to 0·16, during the cool and wet first year. In the warmer and drier second year, the ratio increased to a maximum of 0·72 when flowering started, and thereafter decreased. More than 80% of the root dry matter was found in the topsoil. Roots were longer and thinner in the dry and warm 1990 than in the wet and cool 1987. Maximum root length was c. 4·9 km/m2 in 1990, and mean root radius varied between 01 and 0·7 mm. Increases in root surface area during periods of root growth were due to increased root length rather than to increased mean root radius.
Effects of date of planting, date of harvesting and seed rate on yield of seed potato crops
Authors: O'Brien P. J. , Allen E. J. 
Published: March 2009

SUMMARYFourteen experiments which studied effects of date of planting in July, date of harvesting and seed rate on seed tuber yields (10–51 mm) of several potato varieties were carried out in four seasons in East Anglia. Seed tuber yields of c. 30 t/ha in Estima, Wilja and Maris Piper and 20 t/ha in Record were produced from the early planting and in all varieties c. 20 t/ha were produced from planting in late July. For maximum seed yield in all varieties, seed rates of 1·5–2 t/ha were sufficient for most harvests from both dates of planting but for the earliest harvest of the late-July planting, seed rates of only 1–1·5 t/ha were required. The value of seed crops was assessed as the number of ware hectares that could be replanted from the seed yield of one hectare graded 10–51 mm. In all varieties, the number of seed-size tubers and replantable hectares increased with increasing seed rate over most of the range, but numbers were close to the maximum at the early harvests. With delay in harvesting, the number of seed tubers and replantable hectares decreased in many experiments, especially from low seed rates, as more tubers exceeded the upper seed size limit. Maximum numbers of replantable hectares of 15, 15, 20 and 25 were found in Record, Estima, Wilja and Maris Piper, respectively.The monetary value of seed crops of Record and Maris Piper was calculated using (i) a fixed price per tonne of seed and (ii) cost of seed per replantable ware hectare. Sale values from the latter were substantially higher than from the former at early harvests in Record and at all harvests in Maris Piper. In Record, differences in sale value between the two pricing methods decreased with delay in harvesting as yields increased while number of replantable hectares varied little. The results showed that high multiplication rates and monetary returns can be obtained from short-season seed potato crops which may follow crops harvested earlier in the same season. The implications for potato production in the UK are discussed.
Modification of the analytical procedures for the determination of herbage and faecal n-alkanes used in the estimation of herbage intake
Authors: Vulich S. A. , Hanrahan J. P. , Crowley B. A. 
Published: March 2009

SUMMARYThe evaluation of n-alkane concentrations in herbage and faeces is the basis of a methodology that yields precise estimates of herbage intake. Established chemical analysis procedures for the determination of n-alkane concentrations in herbage and faecal samples involve an elaborate sequence of steps utilizing n-hexane as solvent for both the liquid-liquid extraction of n-alkanes from the sample and the solid-phase separation of n-alkanes in the extract. Composites of herbage and faecal samples from studies with sheep provided the experimental material used to evaluate a series of modifications which would simplify and reduce the workload involved in the chemical analysis. The results show that a less hazardous chemical, n-heptane, can replace n-hexane at all stages of the analytical procedure. They also show that evaporation of the sample extract and redissolving it prior to the separation of the n-alkanes, using a silica gel column, is unnecessary and that the volume of solvent used can be reduced. Procedures for saponification of samples prior to extraction can also be simplified as the process can be run overnight involving a slow build-up of temperature to 90 °C. The gain in precision from processing samples in duplicate was negligible and it would be more appropriate to invest extra efforts on an increased number of experimental animals. The results snowed that the workload and cost of using the n-alkane technique to estimate herbage intake can be reduced substantially.
Residual effects of N, P and K applied to cotton on following crops of sorghum, dolichos and wheat in the Sudan Gezira
Authors: Burhan H. O. , Said M. B. 
Published: March 2009

SUMMARYResidual effects of N, P and K applied to cotton on the following crops of dura (Sorghum vulgare), lubia (Dolichos lablab) and wheat (Triticum vulgare) were investigated using data obtained over a 30-year period from a factorial field experiment including various levels of the three nutrients. The three crops differed in their response to residual N, P and K. Dura and wheat, being nitrogen depleters highly responsive to fertilizer nitrogen, were consistently affected by residual N. The residual effects of N on grain and straw yields of both dura and wheat were significant in all seasons and the effects were proportional to the amount of N applied to the preceding cotton. There were indications, however, that a much greater part of the N applied in the preceding year was not available to the succeeding crop. Residual P did not have a significant effect on dura but it varied in its effect on the different components of wheat in different seasons. Residual K did not have any effect on dura or wheat. Data on nutrient uptake and composition of wheat tended to support the yield responses. Contrary to the response of the two cereal crops lubia, being a nitrogen fixing legume, did not respond to the effect of residual N and was consistently affected by residual P. Residual K had a slight effect on lubia in only a few seasons.
The presence of indigenous glauconite in soils and its effect on soil fertility:II. Soils developed on Gault Clay (Denchworth series)
Authors: McRae S. G. 
Published: March 2009

SUMMARYTwelve stagnogley soils of the Denchworth series from East Kent were studied to determine the effect of indigenous glauconite on their fertility. The presence or absence of glauconite was not the major factor controlling the potassium or magnesium status which was largely determined by the nature of the < 2 μm clay. Glauconitic soils had much higher levels of available phosphate than corresponding non-glauconitic soils due to calcium phosphate associated with the glauconite in the parent material. Weathering has partially converted this to aluminium and iron phosphates which were the main forms of phosphate present, especially in the A (0–15 cm) horizons.