bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of grazing intensity on herbage consumption and animal production: III. Dairy cows grazed at two intensities on clean or contaminated pasture
Authors: Greenhalgh J. F. D. , Reid G. W. 
Published: March 2009

SUMMARYOn three occasions in May—July one half of a ryegrass pasture was grazed intensively by cattle and the other was mown. In August and September these areas, designated fouled (F) and clean (C) respectively, were each strip-grazed by two groups of five cows. One group on each area had a herbage allowance of 11·4 kg dry matter per cow per day (C11 and F11) and the other 20·4 kg (C20 and F20).Before the August-September grazing the fouled area had 2·8% of its surface covered by faeces. After this grazing 23 % of the F n area and 34 % of the F20 area were classified as having been rejected by the cows. However, the upper parts of the sward on these rejected areas were in fact grazed. There were only small differences in N and soluble-carbohydrate contents between the herbages offered and rejected.Organic-matter digestibility (%) and intake (kg/cow per day) for the four groups were: C11, 73·0 and 10·5; C20, 74·9 and 11·7; F11 , 74·4 and 9·6; F20, 77·0 and 10·6. The C11 cows consumed all the herbage allowed to them, but the F11 rejected 13%. Digestible organic matter intake was affected more by grazing intensity than by fouling; this was the case also for milk yield, milk composition and the live-weight change of the cows.
Experiments on the nutrition of the dairy heifer: VIII. Effect on milk production of level of feeding at two stages of the lactation
Authors: Broster W. H. , Broster Valerie J. , Smith T. 
Published: March 2009

SUMMARYEighty Friesian heifers were used to study the effect on milk production of two fixed levels of intake at two stages of the lactation. The rations were estimated to contain 7·9 and 6·2 kg starch equivalent per day, with adequate protein content. The heifers were allocated at random to these two levels of intake for weeks 1·9 of lactation and re-allocated at random to them for weeks 10–18 of lactation. Apart from minor variation the heifers were all fed alike for the remainder of the lactation.The higher level of feeding increased yields of milk and milk solids and solids-not-fat content in each period but had a smaller effect in mid- than in early lactation, a trend which was shown to continue further into later lactation. It also conserved body reserves.There was a residual effect in weeks 10–18 from the level of feeding in weeks 1–9 of lactation. This was directly additive to the effects of the current level of feeding. Those animals which had received the higher level of feeding in weeks 1–9 yielded more milk of higher solids-not-fat content than those which had had the lower level of feeding in weeks 1–9. The former group gained less live weight. The effect on milk production over the full lactation from additional feeding in early lactation was three times that observed in early lactation itself. Additional feeding in mid-lactation did not have a residual effect.The absolute output of milk per unit of food over the 18-week period was greatest for that group which had received the lower level of feeding throughout, followed by the group which received the higher level of feeding in weeks 1–9 only. This superiority was achieved at the expense of body reserves. There was a negative regression of live-weight change on milk production.Estimated intakes of metabolizable energy agreed closely with requirements for milk production as indicated by the Agricultural Research Council (1965).
The nutrition of the bacon pig. I. The influence of high levels of protein intake on growth, conformation and quality in the bacon pig
Authors: Woodman H. E. , Evans R. E. , Callow E. H. , Wishart J. 
Published: March 2009

The present practice of basing payment for bacon pigs not merely on carcass weight, but also on carcass quality as expressed in the factory grading results, has led necessarily to an enlargement of outook on the part of the investigator in the domain of swine nutrition. The interest of the experimenter in the past has tended to be restricted to such questions as the influence of nutritional factors on the rate of live-weight increase and the efficiency of food conversion, the problem of how feeding may influence carcass quality and conformation not having received the attention its importance merited.While the questions of the rate of growth and the efficiency, in terms of meal consumption, with which such growth is achieved are still matters of primary economic importance, it is realized that much more attention must be devoted than heretofore to the study of carcass quality and conformation in relation to feeding. In present circumstances, a nutritional investigation can scarcely be considered complete unless a substantial part of the research is carried out in the bacon factory following the slaughter of the experimental animals.
The base status of Scottish soils. I. The effects of lime on five typical soils from north-east Scotland
Authors: Mitchell R. L. 
Published: March 2009

The effects of lime on five soils representative of types from northeast Scotland have been studied and different lime requirement methods compared.Laboratory analyses including mechanical and ultimate chemical analyses, pH, exchangeable cation and lime-requirement determinations were carried out on samples taken before and at two intervals of 6 months after the application of lime.In some cases the maximum effect of the lime applied occurs within 6 months, in others neutralization is continued during the second 6 months.The change in pH value varies, according to the soil type, from 0·5 to 1·0 pH units per ton of calcium oxide applied per acre.
The effect of maturity and leafiness on the intake and digestibility of alfalfas and grasses fed to sheep
Authors: Troelsen J. E. , Campbell J. B. 
Published: March 2009

SUMMARYThe effect of maturity on the nutritional quality of hay from two alfalfa varieties and four grass species was studied. Each hay was harvested at six different stages of growth, chopped in 4–6 cm lengths, and fed to sheep in quantities of 10% in excess of voluntary intake. The relationship between intake (Y) and digestibility (X) of dry matter was best expressed by regressions of the form: Y = a + b1X + b2X2. The rate of intake declined 1·5 g daily per kg0·75 of body weight per unit decrease in digestibility percentage, and was the same for both alfalfa and grass hays. However, the intake of alfalfa hay was about 10% higher than that of the grass hays of similar digestibility. No differences in the relationship between intake and digestibility (P < 0·05) were observed between the two alfalfa varieties or between the four grass species. When the nutritional quality was expressed as voluntary intake of digestible organic matter daily per kg0·75 of body weight, and time of harvest as day-number of the year, the difference in quality between the six kinds of hay was very small or absent at the beginning of the season (immature to prebloom) and increased toward maturity (dough stage to seed ripe). The decline in quality of alfalfa hay was slower than that of grass hay, and ceased at the mature to overripe stage. On the average, voluntary intake of digestible organic matter declined 0·29 g daily for each day delay in harvest time; this decline varied from 1·2% of the daily intake of digestible organic matter in the beginning of the season to 0·6% at the mature stage. Time of harvest ‘accounted for’ 77–89% of the variation in the quality of the hays. The confounded effect of maturity and leanness on the nutritional quality of the hays was expressed best by concave, second degree polynomial regressions. On the average a unit decline in percent leaves corresponded to a decline of 0·58 g and 0·73 g respectively in the daily intake of digestible organic matter from alfalfa and grass hay. This varied from over 1 g early in the season to less than one tenth of a gram late in the season. The confounded effect of leafiness and growth stage ‘accounted for’ over 75% of the variability in nutritional quality. The relationship between intake and digestibility of the alfalfa and grass hays was used to illustrate how voluntary intake of metabolizable energy (percent of requirement for maintenance) from hay of pure or mixed species may be predicted from in vitro digestibility.
Body temperature lability in sheep and goats during short-term exposures to heat and cold
Authors: Johnson K. G. 
Published: March 2009

SummaryPassive lability of body core temperature during brief exposures to thermal stress is an efficient means of thermoregulation which few species of domestic animals appear to utilize. The body temperature changes of 30 shorn sheep and 10 shorn goats have been measured during standard heat and cold exposures lasting 7 h. During exposures to heat, air temperature was increased from 20 °C to 45 °C then reduced again to 20 °C. Rectal temperatures of goats and Soay, Welsh Mountain, Merino and Clun Forest sheep rose by an average of 1·96 °C, 1·22 °C, 1·04 °C, 0·85 °C and 0·80 °C respectively. All animals had similar increases in respiratory rate. During exposures to cold, air temperature was reduced from 20 °C to about 6 °C then increased again to 20 °C. Rectal temperatures rose by 0·18–0·20 °C in goats and in all sheep except Soays in which they fell by 0·28 °C. All animals showed moderate to vigorous shivering. None of the animals exhibited passive body temperature lability as an adaptation to thermal stress.
The response of perennial ryegrass to nitrogen in various periods of the growing season
Authors: Cowling D. W. , Lockyer D. R. 
Published: March 2009

SUMMARYThe response of irrigated, perennial ryegrass to fertilizer nitrogen was studied in four consecutive periods of the growing season by applying 0–350 kg N/ha to a fresh sward at the start of each period, and measuring both herbage dry matter and its content of nitrogen.Responses in yield were highest in the first period, which ended at inflorescence emergence; in this period, both the percentage recovery of nitrogen and the extent of its utilization in producing dry matter were greater than in the later periods. Some damage to the sward was seen following the harvest of grass grown with the high levels of nitrogen in the first period. When the yields were 90% of the predicted maximum the nitrate-N content of the herbage ranged from 1000 to 2000 ppm, except in the first period when it was 200 ppm.The response curves were used to calculate the nitrogen requirements of the grass which would maintain given incremental yield responses. To produce near-maximum yields, irrigated grass swards may require fertilizer nitrogen equivalent to 2 kg N/ha/day prior to inflorescence emergence, and up to 5 kg N/ha/day for the remainder of the growing season.The apparent efficiency of conversion of the radiant energy, usable for photosynthesis, into plant energy averaged 3·2%; it did not vary greatly among the four periods.The experimental results indicate the seasonal requirements of grass for fertilizer nitrogen and some of the implications for animal husbandry are discussed.
The effect of diet on glucose entry rates in sheep
Authors: Ulyatt M. J. , Whitelaw F. C. , Watson F. G. 
Published: March 2009

SUMMARYAn isotope dilution technique has been used to measure the rate of entry of glucose into the metabolic glucose pool and its rate of oxidation in three sheep given diets of barley (85% barley, 15% protein-mineral-vitamin supplement), dried grass or hay. A latin-square design was used and the sheep were fed continuously from an automatic feeding device.Despite large differences in the amounts of α-linked glucose polymer and of crude protein supplied by the diets there were no significant differences between treatments in glucose entry rate, in plasma glucose concentration or in the size of the total body pool of glucose.Calculations based on the specific radioactivity of expired CO2 after 3 h infusions indicated no significant differences between treatments in the percentage of glucose oxidised to CO2 or in the percentage of expired CO2 derived from glucose. The absence of a final ‘plateau’ position in the CO2 activity-time curve, even after 6 h infusions, casts doubt on the validity of these calculations.
An evaluation of Merino wool quality: III. The prediction of uniformity of fleece characters from fleece and skin characters of the birthcoat
Authors: Gallagher J. R. 
Published: March 2009

SUMMARYFibres of anomalous length or diameter are undesirable in the Merino, a breed noted for uniformity of fleece characters. Previous studies which have aimed at estimating adult fleece quality have been based on visual appraisal of the birthcoat. This study was undertaken to test the prediction of uniformity of fibre length at 10½ months and fibre diameter at 15 months from the objective measurement of birthcoat fleece and skin follicle characters.The results indicated that fibre length uniformity at 10½ months cannot be predicted from measurement of fleece or skin characters at birth. It was found that fibre diameter uniformity at 15 months can be predicted from objective measurement of mean fibre diameter of the birthcoat but not by visual appraisal.
Effect of autumn shearing on breeding activity in Clun Forest ewe lambs
Authors: Dýrmundsson Ó. R. , Lees J. L. 
Published: March 2009

SUMMARYSeventy-two Clun Forest ewe lambs were randomly stratified into three groups (I, II and III) of 24 each according to date of birth and body weight at 6 October 1970. The ewe lambs of Groups I and II were shorn on 15 and 30 October, respectively, and Group III acted as unshorn control. The ewe lambs were reared under natural field conditions but supplementary feeding and shelter were provided during the winter months.A large proportion (94%) of the ewe lambs attained puberty in their first year and differences between the three groups in the number of ewe lambs reaching this stage of development were small and not significant. Autumn shearing of ewe lambs was associated with a very slight but statistically wholly insignificant delay in the mean date of puberty whereas the duration of cyclic activity in these lambs was not affected by such treatments.
Studies on mixtures of dwarf sorghum and beans (Phaseolus vulgaris) with particular reference to plant population
Authors: Osiru D. S. O. , Willey R. W. 
Published: March 2009

SUMMARYAn experiment is described in which the possible yield benefits of mixing dwarf sorghum and beans were examined under intensive farming conditions. A ‘replacement series’ of pure sorghum, two-thirds sorghum/one-third beans, one-third sorghum/twothirds beans and pure beans was used at four plant populations. A high level of nitrogen was applied to the sorghum to eliminate the effects of nitrogen transfer from the beans.Yields of the mixtures were up to 55% higher than could be achieved by growing the crops separately. As with some earlier maize/beans experiments (Willey & Osiru, 1972), it is concluded that these yield increases must have been due to a greater utilization of environmental resources. It is suggested that the main factors which made this possible were probably the different rooting depths of the two crops and their different growth cycles.In agreement with the earlier experiments, mixtures which consisted of two-thirds sorghum/one -third beans gave greatest yield increases at high populations and also had a higher optimum population than the pure stands. However, no such trends were apparent in the mixtures which consisted of one-third sorghum/two-thirds beans.For both species intra-specific competition was greater than inter-specific competition. In contrast to the earlier maize/beans experiments, the relative interspecific competitive abilities of the species changed with change in the initial proportions of species in the mixtures. In the two-thirds sorghum/one-third beans mixtures the sorghum was the more competitive species, whilst in the one-third sorghum/two-thirds beans mixtures the bean was the more competitive species. Also in contrast to the maize/beans experiments, these relative competitive abilities were not affected by change in theoverall plant population pressure.
A comparative study of the feeding value of dried sugar-beet pulp for milk production
Authors: Castle M. E. 
Published: March 2009

SUMMARYTwo 16-week experiments with lactating Ayrshire cows were conducted to study the effect on milk production of replacing barley with dried molassed sugar-beet pulp on an equal dry-matter basis. The cows on all treatments received equal weights of hay, groundnut cake and minerals but the contents of barley and of sugar-beet pulp each varied from 0 to 80% in the different concentrate mixtures. The total daily intake of dry matter expressed as a percentage of live weight averaged 2·64 and 2·72 in the two experiments.The average yield of milk in the two experiments was 18·8 kg/cow per day, and, within each experiment, the mean yields of milk and the contents of solids-not-fat and crude protein were not significantly different on the contrasting feeding treatments. The intake of water was significantly increased as the dried beet pulp replaced the barley but no major changes occurred in the proportions of V.F.A.S in the rumen liquor.It is concluded that barley and dried molassed sugar-beet pulp had the same feeding value on a dry-matter basis when used in the production ration of milking cows. It is suggested that for most purposes barley and dried sugar-beet pulp are interchangeable on an equal weight basis, but for more precise feeding the two feeds should replace each other on an equal dry-weight basis.
The improvement of bracken dominated hill pasture using herbicides, reseeding, fertilizers and cutting
Authors: Farnworth J. , Davies G. M. 
Published: March 2009

SummaryBracken-dominated hill pasture was treated with combinations of bracken and pasture herbicides and two reseeding techniques against a background of fertilization and liming. Picloram and dicamba gave high levels of bracken control and reduced carbohydrate levels in the rhizome. Both paraquat or reseeding with minimal cultivations increased yield of digestible organic matter by reducing competition from native weed grass species and promoting better establishment of ryegrass.
Ruminal digestion of chloroplasts and the protection of protein by glutaraldehyde treatment
Authors: Mangan J. L. , West Janet 
Published: March 2009

SummaryChloroplasts, 50–80% intact, were prepared from kale (Brassica oleracea L. var. Marrowstem) by rapid homogenization (3·5 sec) of deveined leaves into partially frozen buffer pH 7·4 made 0·4 M with sucrose, and separated by differential centrifugation. Chloroplasts from 10 kg leaves were administered to the rumen of a sheep and the degradation followed by analysis of the rumen fluid which was collected continuously. Particulate matter of the rumen fluid was separated on discontinuous sucrose density gradients, 8 ml each of 35, 46, 50, 65 and 75% (w/v), centrifuging at 300 g for 1 h at + 2 °C. Chloroplasts were rapidly ingested by entodiniomorphid protozoa and digested with no detectable increase in soluble nitrogen in the rumen fluid. No net production of ammonia occurred but δ-amino-valeric acid increased indicating that amino acid transformations had occurred. Chlorophyll in the ingested chloroplasts was rapidly degraded with a half-life of 50–60 min. In contrast a similar amount of soluble casein added to the rumen degraded with a half-life of 13–14 min with large increase in soluble nitrogen consisting of peptides, amino acids, ammonia and δ-amino-valeric acid. Glutaraldehyde treated chloroplasts were also ingested by protozoa, chlorophyll was rapidly degraded but there was no increase in the soluble nitrogen of the rumen fluid, including ammonia and δ-amino-valeric acid. Water disrupted chloroplasts released soluble protein and in the rumen behaved like casein, producing high proportions of ammonia and δ-amino-valeric acid. The significance of these experiments in the protection of soluble leaf protein from degradation in the rumen of pasture-fed animals is discussed.
Concentrations of intermediate metabolites in the blood and hepatic tissues of pregnant and non-pregnant ewes
Authors: Herriman I. D. , Heitzman R. J. , Priestley I. , Sandhu G. S. 
Published: March 2009

SummarySix late pregnant and six non-pregnant Finnish Landrace × Dorset Horn ewes were fed a standard diet. Blood and liver samples were taken and the concentrations of the following metabolites measured: adenine monophosphate (AMP), adenine diphosphate (ADP), adenine triphosphate (ATP), citrate, 2-oxoglutarate, phosphoenol-pyruvate, pyruvate, lactate, 2·phosphoglycerate, 3·phosphoglycerate, malate, β·hydroxybutyrate, acetoacetate, glutamate, alanine, NAD+ and NADH. Comparing non-pregnant with pregnant ewes the liver of the pregnant animals had reduced concentrations of lactate, ADP, NAD+ and NADH, and in the blood there were reductions in lactate, pyruvate, lactate/pyruvate ratio and urea. The concentrations of the other metabolites of the pregnant ewes receiving adequate nutrition were little changed from those of the non-pregnant ewes. The significance of these findings is discussed.
Concentrations of glucose, albumin, inorganic phosphate and sodium in the blood of beef calves at 2 ½ months of age and their relationships with subsequent weight gain
Authors: Rowlands G. J. 
Published: March 2009

SummaryBlood samples were taken at 9, 10 and 11 weeks of age from 230 male Hereford × Friesian calves, the progeny of 12 Hereford bulls. Concentrations of blood glucose, serum albumin, inorganic phosphate and sodium were measured and correlated with body weights and growth rates until slaughter at 19½ months of age.Correlations between growth rates and glucose concentrations (0·44) and between growth rates and albumin concentrations (0·38) were observed until 4 months of age. Similar correlations between body weights and blood glucose or albumin concentrations persisted until 6 months of age. By 10 months, however, the correlations had begun to decline, and by slaughter they had become insignificant.Correlations between growth rates and inorganic phosphate or sodium concentrations were smaller, and also decreased with age.The effect of hypoglycaemia on growth rate was compared with the effect of enzootic pneumonia. Although the 10% of calves with the lowest glucose concentrations were growing 24% more slowly than the other calves at the time of sampling, this growth depression was not related to pneumonia, and they subsequently made up for most of the early loss of growth.Three blood samples were also taken from 22 Hereford bulls. No significant correlations were observed between the blood composition of the bulls and the body weights or weight gains of their progeny.