bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrogen metabolism in water-restricted Marwari sheep of the Indian desert
Authors: Bohra H. C. , Ghosh P. K. 
Published: March 2009

SUMMARYStudies were conducted to evaluate the effect of 50% restriction of normal daily water intake on nitrogen balance, plasma urea concentration and excretion of different urinary nitrogenous constituents (ammonia, creatine, creatinine, urea and undetermined nitrogen) in the Marwari breed of sheep of the Rajasthan desert, India. The results indicated that the reduction in feed intake in water-restricted sheep leads to a reduction in intake and excretion of nitrogen through faeces (P < 0·01) and urine (P < 0·01) of these animals. No sigficant differences in the excretion of most urinary nitrogenous constituents betweenad libitumwatered and water-restricted animals were observed, except for creatine which was excreted in significantly higher concentrations in the urine of the water-restricted animals. On offering waterad libitumfor 3 days to the restricted animals, the plasma urea in these animals dropped from 33·0 to 20·7 mg/100 ml, i.e. almost to the level in the animals wateredad libitum(18·7 mg/ 100 ml). The daily dry-matter intakes of thead libitumwatered and restricted animals were 790 and 488 g, respectively. The digestibility coefficients for dry matter and crude protein of the feed were 47·1 and 27·2%, respectively inad libitumwatered and 56·6 and 39·5%, respectively, in restricted animals. This improvement in the efficiency of digestion in water-restricted sheep may not be due to any enhanced microbial activity in the rumen, but may possibly be due to an increased absorption of feed nutrients in the hind gut of these animals.
The effect of roughage or concentrate feeding and rumen retention time on total degradation of protein in the rumen
Authors: Ganev G. , Ørskov E. R. , Smart R. 
Published: March 2009

SUMMARYSamples of soya-bean meal, groundnut meal, sunflower meal and fish meal were incubated in nylon bags in the rumens of sheep receiving either whole barley or dried grass. For the vegetable sources of protein the rate of disappearance of protein was greater when they were incubated in the rumens of sheep receiving dried grass than in sheep receiving whole barley. The rate of disappearance of fish meal did not vary between sheep fed whole barley or dried grass.Rate of outflow of protein particles from the rumen was determined by rendering the protein supplement totally indigestible by a treatment with sodium dichromate. The rate of outflow was greatest with sheep receiving dried grass and increased with increasing feeding level.The mathematical expressions of degradation rate and outflow rate were combined to give the total amount of protein degraded in the rumen for the grass and barley diets at two levels of feeding.The amino acid composition of residues left in the nylon bags after 9 h of incubation were shown to be almost identical to the amino acid composition of the original protein supplement, indicating that the composition of the amino acid in the undegraded protein entering the abomasum essentially resembled that of the supplements.
The association of dry-matter yield with nitrogen and soluble-carbohydrate concentration in perennial ryegrass (Lolium perenne L.)
Authors: Valentine J. , Charles A. H. 
Published: March 2009

SUMMARYThe associations between yield, nitrogen and soluble-carbohydrate concentration within S. 23 perennial ryegrass were investigated at three levels of nitrogen application. Controlled growth room conditions were used.The simple correlation between yield and nitrogen concentration was negative at the low rate of nitrogen application, not present at the intermediate rate of nitrogen and positive though not significant at the high rate of nitrogen. Yield and soluble-carbohydrate concentration were only correlated (positively) at the low nitrogen rate.At low nitrogen there were ‘efficient’ genotypes with relatively high yield and low nitrogen concentration. ‘Inefficient’ genotypes had relatively low yields and high nitrogen concentration. The majority of genotypes were neither markedly efficient or inefficient. The efficient genotypes at low nitrogen maintained their yield advantage at higher nitrogen levels with average nitrogen concentration and high numbers of tillers. Inefficient genotypes remained relatively stable in yield, numbers of tillers and nitrogen concentration.Partial correlation indicated an underlying high degree of dependence between yield, nitrogen and soluble-carbohydrate concentration at all nitrogen levels. The association of yield and nitrogen concentration showed a similar trend over nitrogen levels to that obtained using simple correlation. Yield and soluble-carbohydrate concentration were positively related, and nitrogen and soluble-carbohydrate concentration inversely related, when the effects of the remaining attribute were eliminated.Data extracted from Lee et al. (1977) confirmed that yield and nitrogen concentration for varieties under field conditions varied with level of nitrogen application in a similar manner to genotypes in the controlled growth room. The variety (Melle) could be characterized as being particularly efficient.Both sets of results indicate that selection for high yield of nitrogen in herbage can best be achieved through selection for yield alone.
The carcass composition of male, castrated male and female pigs resulting from two levels of feeding
Authors: Davies A. S. , Pearson G. , Carr J. R. 
Published: March 2009

SUMMARYAn anatomical study compared the effects of sex and a twofold nutritional difference in growth rate between 20 and 100 kg live weight, on 63 entire males, castrated male and female Large White × Landrace pigs. While the effect of growth rate was significant for overall fat deposition in the carcasses of all three sexes, it was greatest for the entire male. In contrast, sex and nutritional effects on the distribution of fat and on the proportion and distribution of muscle and bone were small.
The evaluation of a standardized commercial cutting technique for determining breed differences in carcass composition
Authors: Kempster A. J. , Cook G. L. , Smith R. J. 
Published: March 2009

SUMMARYData for 383 steer carcasses from the first 3 years of the Meat and Livestock Commission's Beef Breed Evaluation programme were used to evaluate a standardized commercial cutting technique for estimating breed differences in carcass composition. The sample included carcasses from cattle out of Friesian, Hereford × Friesian and Blue-Grey dams by sires of the main traditional British beef breeds and by Charolais, Limousin and Simmental sires. The left side of each carcass was divided into 14 standardized commercial joints which were deboned and trimmed of fat to a fixed level (commercial cutting); the other side was jointed in the same way and each joint fully separated into lean, subcutaneous fat, intermuscular fat and bone (full separation). Breed means for characteristics obtained by commercial cutting were adjusted to equal carcass subcutaneous fat percentage (SF) estimated by visual appraisal, while those for full separation characteristics were adjusted to equal SF obtained by tissue separation. Breed differences in deboned fat-trimmed joints (saleable meat) as a percentage of carcass weight were in good agreement with those for carcass lean percentage (between-breed correlation, rb = 0·92), as were those for saleable meat to bone ratio and lean to bone ratio (rb = 0·91). There was a poorer relationship between fat trim and separable fat (rb = 0·62) but there was little breed variation in these characteristics at equal SF. Breed differences in the percentage of total saleable meat distributed in higher-priced joints were very similar to those for lean distribution in higher-priced joints (rb = 0·87).
Comparison of the effects of phosphate fertilizer on the yield, phosphate content and quality of 22 different vegetable and agricultural crops
Authors: Greenwood D. J. , Cleaver T. J. , Turner Mary K. , Hunt J. , Niendorf K. B. , Loquens S. M. H. 
Published: March 2009

SUMMARYFifty-six experiments, each with 15 levels of P fertilizer in the presence of excess N and K fertilizer, were carried out on adjacent sites of the same field where the soil was maintained at the same low P status. Yields, in every experiment where there was a response, were related to level of P fertilizer by a diminishing-retums type curve, and fitted an inverse polynomial equation with a single parameter to define responsiveness. Responsiveness of many crops were similar but there were, nevertheless, considerable inter-crop differences.Applications of P fertilizer increased the % P in the dry matter of lettuce and spinach as well as yields. They increased the % P in the Cruciferae and Chenopodiaceae without appreciably affecting yield. Conversely, theyhad little effect on the % P of leeks, onions, broad beans and French beans but increased yields.When the optimum levels of P fertilizer were applied, % P (in the entire plant) of the different crops was negatively correlated with total dry weight per unit area and total uptake of P was related by a single curved relationship to total dry weight. In addition, the difference between the % P in the foliage and in the storage roots of the various root crops was asymptotically related to mean plant weight.Percentage recovery of added P (100 kg/ha) by the different crops was largely determined by the total weight of dry matter. It varied from 1% when crop dry weight was 2 t/ha to 12% when it was 15 t/ha.Applications of phosphate suppressed leaf scorch of spinach. On occasion they alleviated stem rot in summer cabbage and influenced the bolting of onions and the number of defective Brussels sprouts. Otherwise, the effects on quality were small.
Studies on the habits of Zebu cattle IV. Errors associated with recording technique
Authors: Rollinson D. H. L. , Habker K. W. , Taylor J. I. , Leech F. B. 
Published: March 2009

To obtain records of individual animals' habits when a small herd is observed for long periods of time, several observers are essential. The errors between observers were so much less than those between animals and between periods of observation that for most purposes records made by a succession of different observers will be adequate.The errors of observations at 1 and 4 min. intervals, using the grazing records of ten animals, were 3·20 and 7·36% of the mean respectively. The latter figure being of sufficient accuracy for practical application, it is concluded that the 4 min. interval is suitable for records of a major habit.The errors for the minor habits were large relative to the mean time occupied on them, but still reasonable in relation to the purposes for which work of this sort would usually be required.
Investigations into the chemical composition and nutritive value of certain forage plants at medium altitudes in the tropics II. The digestibility and nutritive value of three grasses at different stages of growth
Authors: Todd J. R. 
Published: March 2009

1. The results of nine digestibility trials on three East African grasses, using sheep as experimental animals, are reported.2. In five of the trials Bothriochloa insculpta, at various stages of growth during the season, was used. Chloris gayana (Rhodes grass) was used in two trials, as was Pennisetum clandestinum (Kikuyu grass).3. The results are discussed and are compared with other results from East Africa.4. P. clandestinum has a high digestible protein content and is highly digestible in the early stages of growth, and maintains its high protein content when 9 to 12 in. in height.5. Bothriochloa insculpta and Chloris gayana are moderately highly digestible in the-young stages but are relatively low in digestible protein. As growth ceases during the dry season the digestible protein content falls more rapidly than the starch equivalent with consequent widening of the nutritive ratio.6. It is suggested that the differences between Pennisetum clandestinum and the other grasses may be due to its predominantly vegetative habit.
The effect of date of planting on the yield of potatoes
Authors: Dyke G. V. 
Published: March 2009

Evidence obtained in the Agricultural Improvement Council Survey of Maincrop Potatoes 1948–50 and in experiments shows that yields in England and Wales are decreased by delay in planting after about 11 April at the rate of about 0·4 tons per acre per week. The effect is rather greater in years with fine springs, and on high-yielding fields.In Rothamsted experiments the responses to dung and fertilizers were all greatly reduced when planting was delayed; between early April and late May the effects of dung, nitrogen and phosphate were halved, while that of potash was reduced by about 80%. The evidence on the responses of different varieties to early planting in English experiments is contradictory, except for an indication that higher yielding varieties respond better. Data from Craibstone suggest that, if bulk yield is the only criterion, ‘early’ varieties which make rapid growth early in the season have a later optimum planting date than maincrop varieties.The effect of chitting seed at Craibstone is to increase yields by 1·7 tons per acre for March plantings, and by 2·5 tons per acre for plantings in mid-April and later. There is negligible loss of yield from sprouted seed at Craibstone for plantings delayed up to mid-April, but for unsprouted seed there is evidence of a gain from plantings a month earlier. Sprouted seed planted even as late as 1 May yielded as well as unsprouted planted two months earlier.
Observations on the relationship between riboflavin, hatchability and clubbed down
Authors: Coles R. , Cumber F. 
Published: March 2009

A brief account is given of the accepted view that riboflavin supplements in the diet of breeding stock lead to improved hatchability and that clubbed down is specific for a deficiency of this vitamin. Attention, however, is drawn to the apparent failure of various workers to achieve a hatching rate with a riboflavin supplemented diet substantially in excess of 80% of fertile eggs which appears to be the national average figure. An experiment is described in which range managed breeding stock received diets supplemented with riboflavin at varying levels, the lowest of which, in the light of available evidence, would be sufficient for good hatchability having regard to the riboflavin obtained by the stock from grass and their own droppings. The hatching rate of fertile eggs was maintained at about 80% with all rations and little change took place consequent on changing over from high to low or vice versa. Only a very small improvement was observed with a very high level of riboflavin. It is therefore concluded that either a figure around 80% hatchability represents the maximum influence of riboflavin on hatching rates or that there are generally other factor(s) present (or absent) in the embryo that prevent a higher rate being achieved. The evidence submitted suggests that this factor may be B12 or more probably, one of the unidentified factors in the A.P.F. complex, and that for hatching rates materially above 80% the A.P.F. complex must be increased above the levels presently supplied to range managed breeding stock, or the high hatching rates induced by high levels of riboflavin may greatly increase the birds' requirements for this factor(s) to a level well above that normally necessary.Attention is also drawn to the incidence of clubbed down among dead-in-shell with varying levels of dietary riboflavin. It is concluded that the presence of this embryonic abnormality is rapidly and almost completely influenced by changes in the level of dietary riboflavin and that these changes take place much more rapidly than changes in hatchability, once a moderately high hatching rate has already been reached. It is also contended that high riboflavin levels will almost eliminate the incidence of clubbed down, although an already moderately high hatching rate will remain unaffected. For this reason it is argued that the presence of clubbed down in some dead-in-shell is no conclusive evidence that an improvement in hatchability will follow supplementation of the diet with riboflavin unless the hatching rate is below average.
The feeding of fodder beet to pigs
Authors: Rees D. H. , Westmacott M. H. 
Published: March 2009

1. An examination has been made of the results of a number of experiments on the feeding of fodder beet to fattening pigs.2. When beet is introduced, the daily energy intake and hence the growth rate are slightly reduced.3. The value of beet as a replacement for meal, neglecting the reduction in growth rate, may be assessed satisfactorily from a knowledge of the dry matter content of the beet and of the starch equivalent of the meal, using the average values given by Woodman (1954).4. Where beet is used to replace meal, the available digestible protein is reduced. It is possible that the addition of protein-rich supplements to the ration will improve the performance of the pigs.5. The effects of beet on carcass quality are not clear. The Danish reports examined indicate slightly lower quality, but the English reports similar or slightly higher quality.
Fertilizer placement for horticultural crops
Authors: Cooke G. W. , Jackson M. V. , Widdowson F. V. , Wilcox J. C. , Goodway N. D. 
Published: March 2009

In field experiments on vegetable crops dressings of appropriate fertilizers were placed 2 in. to the side of the seed and 2–3 in. below the soil surface, and compared with the same amounts of fertilizer broadcast and worked into the surface soil. The work was carried out on ordinary arable land carrying rotations which included vegetables.Placing fertilizer gave higher yields of cabbage, lettuce, beetroot, onions, broad beans, runner beans and maize, than broadcasting. Fertilizer, however applied, had no regular effect on the yield of french beans.Both placed and broadcast fertilizer were tested at two rates of dressing. On average of all experiments on each crop, placing fertilizer at the low rate gave higher yields than broadcasting at the high rate. Broadcast fertilizer had little effect on yields of runner beans and broad beans, while placed dressings gave marked increases.In two-thirds of all individual experiments placing gave higher yields than broadcasting, and in one-third of the experiments placement was significantly better than broadcasting. There were no instances of significantly higher yields from broadcasting as compared with placing.Placing fertilizer made most of the crops grow more rapidly in the early stages than broadcasting, this improvement being often reflected in earlier maturity. For cabbage, lettuce and runner beans the relative gains from placing, as compared with broadcasting fertilizer, were much higher at the first than at the second harvest.By drilling fertilizer beside the seed of vegetable crops grown on ordinary soils, it is possible to economize in the dressings needed. In addition, some crops having placed fertilizer may be ready for market earlier. These advantages may be very profitable where high-value crops are grown and will justify the purchase of special placement drills.A small series of field experiments on established Brussels sprouts and autumn-planted cabbages compared mid-season top-dressings of nitrogen fertilizer broadcast by hand over the whole soil surface, with dressings placed at one point beneath the surface and near to the plants. The dressings used had practically no effect on yields of Brussels sprouts. Top-dressings broadcast in spring increased yields appreciably in two experiments on cabbage, and at both centres placing gave lower yields than broadcasting.
A study of the effects of potassium fertilizer with special reference to wheat on boulder-clay soils
Authors: Ralph R. L. , Ridgman W. J. 
Published: March 2009

SummaryA long-term rotation experiment testing the effects of applying K fertilizer in combination with N fertilizer and cropping treatments, and two experiments comparing the effects of residual and freshly-applied K together with N treatments over 3 years, all on boulder-clay soils, together with two detailed studies of the effect of K on the growth of wheat on a chalk soil very deficient in K, are described and the results discussed.Restricting the K supply had little effect on the growth of wheat until stem elongation began, but from then the growth of almost all organs was affected. It is concluded that there is no one mechanism by which lack of K in the soil restricts yield. It can decrease the area of the upper leaves, the dry matter produced in the upper internodes and ears, reduce the number of grains per unit area and the size of grain, but which of these is most important in a particular crop will depend on other cultural and environmental conditions.It is argued that boulder-clay soils should not be considered as a single class when giving advice on K manuring; more experiments are required to make practical recommendations more precise.
Effect of mating management and PMSG dose on lambing outcome in ewes bred in late anoestrus
Authors: Boland M. P. , Crosby T. F. , Gordon I. 
Published: March 2009

SummaryOestrus and ovulation was controlled by progestagen-impregnated sponges in 279 adult dry ewes in late anoestrus: at pessary withdrawal, ewes received doses of 0, 250, 500 or 750 i.u. pregnant mare serum gonadotrophin (PMSG). Rams were introduced to half the number of ewes which did not receive PMSG at the time of sponge withdrawal and to the remainder 48 h later. A significantly lower (P < 0·05) oestrous response was observed in ewes which did not receive PMSG but were introduced to rams at 48 h, when compared with ewes introduced to rams at time of sponge withdrawal. With iams introduced at 48 h a greater precision of synchronization was achieved by the use of PMSG (P < 0·05). Differences in conception rates were not evident between the various treatment groups, but a significantly higher (P < 0·05) litter size followed the use of the 750 i.u. PMSG dose.
Growth, development and yield of pigeon pea (Cajanus cajan (L.) Millsp.) in the lowland tropics:1. Effect of plant population density
Authors: Tayo T. O. 
Published: March 2009

SUMMARYThe growth, development and yield of pigeon pea (cv. Cita-1) grown at three population densities of 27 000, 55000 and 83000 plants/ha were evaluated in two field trials during the growing season of 1980.The results obtained showed that there was a progressive reduction in the developmentv per plant of vegetative characters, dry-matter accumulation and yield characters as population density increased. The calculated growth rates (net assimilation rate, crop growth rate, relative growth rate and leaf area ratio) were more or less the same at all population densities. The yields of seeds were 0·39 and 0·51 t/ha for the lowest population density, 0·43 and 0·65 t/ha for the medium population density and 0·58 and 0·75 t/ha for the highest population density for the two trials respectively.It would seem, therefore, that under the prevailing lowland humid tropical conditions, a population density of at least 80000 plants/ha would be needed to ensure maximum productivity in the sole cropping of pigeon pea.