bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of cereal concentrate supplementation on the digestibility of herbage-based diets for lactating dairy cows
Authors: Arriaga-Jordan C. M. , Holmes W. 
Published: March 2009

SummaryTwo experiments were conducted, one with seven and the other with eight lactating cows, to measure the effect of supplementation with a cereal concentrate on the digestibility of fresh herbage and to provide equations relating digestibility of herbage to faecal indicators. Cattle were housed with free access to fresh herbage from individual Calan–Broadbent gates for recording feed intake, and faecal output was estimated by the use of chromic oxide. In both experiments a cereal supplement depressed herbage organic matter digestibility by 8 g/kg for each kg of fresh concentrate provided within the range 1–6 kg. The depression was associated with reduced digestibility of cellulose. Herbage digestibility was significantly related to faecal nitrogen and faecal cellulose. Herbage intake was depressed by concentrate supplementation and the response in milk yield to supplementation was small.
The Saxmundham rotation experiments: rotation I
Authors: Trist P. J. O. , Boyd D. A. 
Published: March 2009

At Saxmundham Experimental Station in East Suffolk a four-course rotation experiment testing fertilizer treatments has continued with only minor modifications since the 1899/1900 crop year, the crops being wheat, roots (mainly mangolds), barley and either beans, peas or clover. Factorial combinations of nitrogen (N), phosphorus (P) and potassium (K), with two additional treatments testing farm-yard manure and bonemeal, are applied annually to the same plots regardless of crop.All crops, particularly mangolds and sugar beet, yielded badly without P. N was as important as P for cereals, but had little effect on mangolds and sugar beet unless P was also applied; its effects on the legume yields were slight. On this heavy soil K had little effect on the yield of any crops except the legumes.
The effect of the early application of nitrogenous fertilizer and of the time of cutting in spring on the yield of rye-grass/white clover swards
Authors: Cowling D. W. 
Published: March 2009

1. In four different years, swards of perennial rye-grass/white clover were treated with nitrogenous fertilizer (0, 30 or 60 lb. N per acre) in mid-February to produce an early growth of grass. The effect of the time of the first cut, taken in March or April, on the annual yield was studied.2. The total annual yield was reduced when an increasing quantity of grass was removed at the first cut because this interfered with the development of inflorescences and reduced yield at the second cut.3. Fertilizer treatment increased early growth and advanced by 2-14 days the date in spring at which the yield was adequate for grazing; this improvement improvement was small compared with the extent to which this date was affected by differences in the weather from year to year.4. The response in total annual yield to N averaged 17.2 and 14.9 lb. of dry matter per lb. N respectively for the 30 and 60 lb. N per acre applications. The highest responses were measured when little or no grass was removed at the first cut. Where a larger crop was removed at the first cut the response to N was reduced; exceptionally it was negative.
A method of testing the resistance of potato cultivars to tuber damage caused by squeezing
Authors: De Maine M. J. 
Published: March 2009

SUMMARYTubers from nine cultivars grown in four plantings over 3 years at two sites in Scotland were tested for resistance to cracking by squeezing between two flat surfaces. The force was applied by a lever to which a steel plate was fixed, pressing the tuber against a wooden base. The weight on the lever was recorded when wet hair-line cracks appeared on the tuber surface.There were significant differences between cultivars from the same planting. The rank positions of some cultivars were relatively stable but others differed widely between plantings. The grouping of cultivars into the upper, middle or lower parts of the range for squeezing resistance was similar to that for resistance to external damage based on Potato Marketing Board farm surveys. The test could be used to help breeders identify genotypes highly susceptible to external mechanical damage. If combined with tests of resistance to other types of mechanical abuse common in the bulk handling of tubers a more accurate estimate of damage resistance on the farm should be possible.
Studies on the leaching of urea in sodic soils
Authors: Singh Balwinder , Bajwa M. S. 
Published: March 2009

SUMMARYLaboratory experiments were conducted in PVC columns to study the leaching and transformation of applied urea in sodic soils (Gharachon loam-Aquic Natrustalf and Domeli silty clay loam-Aquic Camborthid) reclaimed by gypsum application and kept submerged for 7 or 14 days after fertilizer application. The effect of different depths of irrigation water (5, 7·5, 10, 20 and 30 cm) on urea leaching was studied in a sandy loam sodic soil. In another experiment, the effect of time interval (0 or 4 days) between urea application and initiation of submergence with distilled water (for 7 or 14 days) was investigated involving two recently reclaimed sodic soils (Gharachon loam and Domeli silty clay loam). The results showed that the extent of urea leaching mainly depended upon soil texture. In Domeli silty clay loam, urea penetrated to 20 cm depth with peaks in concentration at 12·5 cm at both 7 and 14 days of submergence. In Gharachon loam urea-N moved to 25 cm depth after 7 days and to 35 cm after 14 days. In the sandy loam sodic soil peaks of urea-N concentration were observed at 12·5, 22·5 and 27·5 cm depths after infiltration of 5, 7·5 and 10 cm depth of water, respectively. Leaching with 20 and 30 cm depths of water moved urea deeper (below 50 and 70 cm, respectively). In recently reclaimed soils, leaching initiated immediately after fertilizer application displaced urea to slightly deeper layers compared with leaching initiated 4 days after urea application. Leaching may not be an important loss mechanism of urea-N in loam or silty clay loam sodic soils. However, in light-textured sandy loam sodic soils leaching beyond the root zone can be expected to create fertilizer management problems.
A device for measuring and sampling urine output from free-grazing steers
Authors: Betteridge K. , Andrewes W. G. K. 
Published: March 2009

SUMMARYA non-surgical device which collects a pre-determined proportion of the urine voided by free grazing male cattle is described. The behaviour of animals trained to wear the collection equipment was similar to that of their contemporaries without the equipment. The performance and maintenance of the device are discussed.
Comparative aspects of copper metabolism in silage-fed sheep and deer (Cervus elaphus)
Authors: Freudenberger D. O. , Familton A. S. , Sykes A. R. 
Published: March 2009

SummaryTen yearling red deer stags (Cervus elaphus) and ten yearling Coopworth wether sheep were housed in individual pens and offered ryegrass-white clover silage, containing 9–10 mg Cu, 1·4–1·7 mg Mo and 2·4 g S/kg D.M., in amounts close to maintenance energy requirement. For six animals of each species the diet was enhanced with 4·8 mg Mo and 3 g S/kg D.M. Liver biopsy samples were obtained during weeks 1, 6 and 12. The animals were then re-randomized and five of each species offered the basal diet and the remainder the basal diet supplemented with 4 mg Cu/kg D.M. Liver biopsy samples were obtained after a further 4½ weeks. Plasma samples for estimation of total and trichloroacetic acid-soluble Cu were taken weekly.The mean liver Cu concentration in sheep was 11-fold greater than in deer. Both diets induced liver Cu depletion, though there was a trend for a greater rate of depletion on the Mo- and S-enhanced silage. The rate of depletion (mg Cu/kg liver D.M./day) was 7-fold greater in sheep than in deer, although it was not possible to determine whether this reflected a species-, as opposed to a Cu status-induced effect. In both species highly significant linear relationships were observed between initial liver Cu concentration and rate of liver Cu depletion. This was interpreted to indicate that endogenous loss was directly proportional to liver Cu content in both species. Individual estimates for the minimum rate of endogenous loss of Cu (μg/kg W/day) ranged from 0·2 to 2·71, mean 1·43, and from 2·83 to 14·75, mean 8·35 in deer and sheep, respectively.During repletion the rate of increase of liver Cu in supplemented groups tended to be greater in sheep than in deer and calculated minimum values for availability of Cu were 0·061 and 0·037, respectively.Liver Cu concentrations of less than 20 mg/kg D.M. were maintained in deer for several weeks without apparent symptoms of deficiency.
A comparison of the effects of liquid manure (urine and water) and nitrogen fertilizers applied to a grass-clover sward on soils of different pH value
Authors: Castle M. E. , Reid D. 
Published: March 2009

SummaryIn a 3-year plot experiment on a perennial ryegrass plus white clover sward the pH of the soil on the main plots was adjusted to, and maintained as nearly as possible at, target levels of 5·25, 6·00 and 6·75 by applying either sulphur or lime. Within the main plots the effects on herbage yield, clover content and crude-protein content of applying four fertilizers were compared at nitrogen rates of 225 and 450 kg/ha annually. The fertilizers were liquid manure (urine plus water), prilled urea, a urea solution and an ammonium-nitrate fertilizer. The applications of the urea and the ammonium-nitrate fertilizers were accompanied by dressings of a potassium fertilizer which supplied the same weights of potassium as in the liquid manure. On average the smallest yields of dry matter and crude protein were associated with the lowest soil pH with no significant interactions between pH and fertilizer treatment. The liquid manure gave slightly smaller total yields of mixed herbage dry matter than the other fertilizers, particularly at the low nitrogen rate. The herbage from the liquid manure treatment had a higher clover content and produced a greater total yield of clover dry matter. The effects of the liquid manure on the clover agree with those noted in previous experiments, but no evidence was found that these effects resulted from the liquid manure increasing the pH of the soil and improving the conditions for clover growth. Similarly, no proof was obtained that the clover effects were due to the nitrogen in the liquid manure being wholly in the ammonium form. However, the value of liquid manure as a fertilizer for grassland was demonstrated clearly.
Ecology of pastoralism in Ngorongoro Conservation Area, Tanzania
Authors: Homewood Katherine , Rodgers W. A. , Arhem K. 
Published: March 2009

SummaryThis management-oriented study of range, livestock and Maasai ecology in the wildlife conservation and pastoralist land use Ngorongoro Conservation Area (NCA) quantifies spatial and temporal variation in range resources for three main study sites over a 2-year period. Livestock response is analysed in terms of biomass densities, habitat and pasture utilization, activity, herd size, composition and dynamics. Milk production is investigated together with the main ecological factors influencing yields. A household survey of the Maasai food system suggests that pastoral products now provide an annual average of 40% dietary energy intake, the remainder being supplied by grain. These findings form the basis of our analysis of the growing friction between the Conservation Authority and the pastoralists. Pastoralist livestock closely resemble wild ungulate utilization of NCA range resources. A combination of disease interactions and administrative restrictions allow wildlife to establish preferential access to critical grazing resources. Our results in the context of other work suggest that contrary to popular opinion pastoralist land use is an ecologically appropriate and efficient form of livestock management. There is no adverse impact on the conservation values of NCA. Despite average fertility and mortality levels pastoralist herds show progressive decline due to offtake for grain purchase. Imposed policies restrict grazing, ban cultivation and maintain poor conditions for livestock trade and grain supply. Possible interventions and their potential impacts are considered and management compromises which could benefit both pastoralists and wildlife are proposed.
The effect of drinking frequency on some aspects of the productivity of zebu cattle
Authors: Nicholson M. J. 
Published: March 2009

SummaryA 28-month trial was carried out under extensive grazing conditions to examine the effects of giving water to Boran cattle once daily, once every 2 days, and once every 3 days, with cattle having ad libitum access to water serving as the control. In the dry season, the weight and condition of lactating cows given water every 3 days declined more rapidly than that of cows given water daily. Calving rates and birth weights were unaffected by treatments although when compared with cows given water ad libitum, birth weights were depressed by 2·5 kg in all treatments. Thirty steers showed no treatment differences in 28-month weights despite a depression in dry-matter intake in the dry season by animals given water every 3rd day. In contrast, 210-day weaning weights were significantly depressed by 9 kg when cattle drank water every 2 days and 14 kg when they drank every 3 days compared with calves given water daily. Total water consumed was depressed in all classes of stock by 5–10% under the 2-day regime and by 25–34% under the 3-day regime when compared with cattle given water daily. The results show that giving water every 3 days can be carried out indefinitely with all classes of stock with only minor effects on cattle productivity under the climatic conditions in which the trial was held. The management implications of giving water every 2 or 3 days to cattle under extensive, pastoralist and ranching conditions are discussed.
The influence of sodium supplementation on the voluntary intake and digestibility of low-sodiumSetaria sphacelatacv. Nandi by cattle
Authors: Little D. A. 
Published: March 2009

SummaryThis study examines the effect of sodium (Na) supplementation on the intake and digestibility of Na-deficient feed by cattle, and the potential applicability of faecal analysis to the diagnosis of Na deficiency in the field. Mature cattle fitted with oesophageal fistulae were fed chaffedSetaria sphacelatacv. Nandi hayad libitumin metabolism cages, with and without a Na supplement (10 g Na daily as NaHCO3). In the first of two experiments the hay contained 0·44 g Na/kg D.M., and in the second, 1·05 g/kg. Prior to an unsupplemented treatment the animals were rapidly depleted of Na by removal of saliva via the fistula; Na status was assessed on the basis of the ratio Na/K in saliva.When the feed contained 0·44 g Na/kg, Na supplementation increased voluntary intake by 28% (P < 0·01) and digestibility by 12% (P <0·05). No such responses were obtained in Expt 2, in which the feed contained 1·05 g Na/kg.Examination of available data suggests that a diagnosis of Na deficiency in cattle is indicated if the faecal Na concentration is below 1 g/kg D.M., and the ratio Na/K in faeces is less than 0·1. Further data are required to confirm these criteria, which should prove useful in the field when samples of saliva, the diagnostic criterion of choice, are not available.
Volatile fatty acids in the ruemen of sheep fed grass, unwilted and wilted silage, and barn-dried hay
Authors: Anderson B. K. , Jackson N. 
Published: March 2009

SUMMARYExperiments were carried out to assess the effect of the following diets: unwilted and wilted silage, barn-dried hay and wilted silage and ensiled mixtures of grass and barley on the ruminal VFA patterns in sheep.There was a tendency for the unwilted silage to result in a slightly higher level of rumen acetate and a lower level of propionate than grass, wilted silage or barn-dried hay. In two of the experiments (Exps. 2 and 4) significant direct relationships were found between rumen acetate and the crude-fibre content of the diets and significant inverse relationships were found between the rumen propionate and the crude-fibre content of the diets.Significant relationships were also found between the rumen acids and the metabolizable energy content of the diets and in Exp. 2 there was a significant relationship between the rumen acetate and the water-soluble carbohydrate content of the diet.The addition of barley meal to grass produced different ruminal VFA patterns in sheep fed the ensiled material and the resulting silage.
Effect of presence or absence of rumen ciliate protozoa on some blood components, nitrogen retention, and digestibility of food constituents in lambs
Authors: Akkada A. R. Abou , El-Shazly K. 
Published: March 2009

1. The levels of blood reducing sugars, haemoglobin, protein N, NPN, ammonia N, and urea N in addition to the nitrogen retention and digestibility coefficients of food constituents, were studied in lambs with and without ciliate protozoa.2. The inoculated lambs have higher blood haemoglobin, protein N, and lower reducing sugars, ammonia N, and urea N values than those of the uninoculated lambs.
The relationship between crop yield (or mean plant weight) of lettuce and plant density, length of growing period, and initial plant weight
Authors: Scaife M. A. , Jones D. 
Published: March 2009

SUMMARYLettuce obeys the Shinozaki–Kira relationship in which the reciprocal of plant weight is linearly related to plant density. The intercept (a) represents the reciprocal of the weight of an isolated plant and the slope (b) represents the reciprocal of yield/unit area at high densities (the ‘ceiling yield’). This work examines the time course of (a) and (b) in an ‘ideal environment’ in which water and nutrients are non-limiting, and the light/temperature regime is constant.Two pot experiments are described: the first showed that the growth of isolated lettuces follows a logistic expression, which can therefore be substituted for a–1 in the Shinozaki-Kira equation. It was then hypothesized that b–1, the ‘ceiling yield’ would be constant over time. This was confirmed by the second experiment, giving the equationw–1t = w–10 e1–kt × w–1max × bd,in which wt is mean plant weight at time t, w0 and wmax are the initial and final weights of isolated plants, k is the early relative growth rate of such plants, b–1 is the constant ceiling yield, and d is the plant density.Two examples of the use of the equation are given: one shows how it predicts the interaction between seed size and plant density within a species (subterranean clover): the other illustrates how it can be used to explain why lettuce growth appears to be log-linear against time whereas cereal growth is more nearly just linear.
The significance of crop residues to the maintenance of fertility under continuous cultivation at Samaru, Nigeria
Authors: Jones M. J. 
Published: March 2009

SUMMARYThe residues from a continuous millet–maize rotation, grown at two levels of phosphate and two levels of nitrogen fertilization, were either burned and the ash incorporated; chopped and incorporated unburned; or completely removed. After 3 years, differences in soil organic matter were small and largely non-significant, but the ash treatment had minimized the general fall in soil pH, and the ash and the unburned residue treatments had both conserved topsoil exchangeable K and Mg, which, where the residues had been removed, had declined by 44 and 12%, respectively. Fertilizer effects were also significant; single superphosphate had increased exchangeable Ca and lessened the fall in soil pH; calcium ammonium nitrate had depleted exchangeable Mg generally and had lowered pH and exchangeable Ca particularly where unburned residues had been returned.A balance sheet of soil cations (0–30 cm), drawn up from soil and crop analyses and known fertilizer inputs shows, first, that whereas the calcium added in single superphosphate increased the exchangeable reserves of this nutrient, that added as calcium ammonium nitrate did not and must be presumed lost by leaching; secondly, the decline in exchangeable K where residues were removed was much less than the total crop removal, indicating a probable substantial release from non-exchangeable form.In the fourth season, treatment-induced soil differences, in particular the ratios between exchangeable cations, significantly affected the chemical composition of the maize test crop but not its final yield.
Influence of doe age on incidence of multiple births and perinatal reproductive wastage in West African Dwarf goats
Authors: Osuagwuh A. I. A. 
Published: March 2009

SUMMARYBreeding records over 12 years (1977–89), involving 455 West African Dwarf does derived from an original population of 133 breeding does, were used to examine the influence of dam age on the incidence of multiple births and perinatal reproductive wastage due to abortion and neonatal deaths. The animals were semi-intensively managed in two goat research units at the University of Ibadan Teaching and Research Farm.The regression results showed that the variable component, multiple births, increased (P < 0·01) linearly with advancing age of the doe, while the incidence of abortionsand neonatal deaths increased (P < 0·01) exponentially with doe age. Graphs plotted from the regression results indicated a sharp increase in the incidence of abortion and neonatal deaths between the ages of 6 and 7 years. This suggests that the practice of keeping these animals for longer than necessary, especially in rural areas of the country where they are mostly reared and kept for prestigious reasons, should be re-evaluated. Therefore it is recommended that to maintain an economically viable production system, does should be culled between the ages of 6 and 7 years and the provision of replacements planned accordingly.
Prediction of body composition of live cattle using two ultrasonic machines of differing complexity: a report of four separate trials
Authors: Kempster A. J. , Cuthbertson A. , Jones D. W. , Owen M. G. 
Published: March 2009

SUMMARYResults are reported from four separate trials carried out to determine the precision of the Sonatest (simple A-mode ultrasonic machine) and the Scanogram (modified linear scanner) for predicting the body composition of live cattle. Cattle in the four trials differed in breed, sex and origin, and the data provided an opportunity to determine the consistency of results in different circumstances. A total of 210 cattle were involved.Fat thickness measurements (Sonatest and Scanogram) and fat and M. longissimus areas (Scanogram only) were taken at the 10th and 13th ribs and at the position of the 3rd lumbar vertebra. Their precision as predictors of carcass tissues percentages was examined when they were used in addition to live weight at evaluation.There was little consistency between trials in the positions and measurements which gave the most precise prediction. The lowest within-breed residual standard deviations of carcass lean percentage obtained with fat thickness measurements taken by Sonatest were in the range 2·5–2·7 and there was little advantage in using additional measurements in multiple regression.Fat areas taken by Scanogram were more precise predictors (within-breed residual standard deviations were close to 2·0). Precision was improved marginally to about 1·8 by using combinations of fat areas but M. longissimus areas were of little additional value.