bluuebunny/crossref_metadata_2025_split huggingface dataset:
Voluntary intake of low-protein diets by ruminants: II. Intake of food by sheep
Authors: Elliott R. C. 
Published: March 2009

1. A study was made of the voluntary intake of hay of low nutritive value by sheep when given four different amounts of concentrate foods (9, 18, 27 and 36 g/kg W0.73/day) each providing three levels of protein (1·3, 2·6 and 3·9 g DCP/kg W0.73/day). Hay alone was offered as a separate treatment. The trial was designed as an incomplete Latin square with thirteen treatments, thirteen sheep and four replicates.2. Voluntary intake of low-protein hay by sheep was invariably lowered when they were given increasing amounts of concentrates. Hay consumption was also affected by level of supplementary protein; intakes increasing sharply from the lowest level provided (1·3 g DCP/kg metabolic body weight) to maximal intakes when about 3 g DCP/kg W0.73 were given to the sheep.3. Total food and digestible energy (DE) intakes were similarly affected by changes in dietary protein level. Successive increments in concentrate allowances, except at the highest level of concentrate input, caused corresponding reductions in hay intake so that total food consumption remained similar (when protein level was kept constant). In consequence, DE intakes rose to maxima when approximately 30 g concentrate/kg W0.73/day were fed to the sheep.
Soyabeans in Tanzania: II. Seasonal variation and homeostasis in soyabeans
Authors: Auckland A. K. 
Published: March 2009

1. Investigations of individual soyabean families over a 5-year period showed in some famines that the strain compounded in theF5generation had a more stable environment × genotype interaction than the daughter strains compounded in theF6generation.2. Regression of each strain yield on an ‘environmental’ mean gave values for the slope of the regression line (bi), and the mean square of the regression (s2d) gave a value of deviations from the regression line. The valuesbiands2dwere used as estimates of stability.3. Groups ofF5andF6compounded strains were compared. Analysis of variance for yield over 5 years for twenty-fourF5compounded strains and twentyfourF6compounded strains gaves2dvalue of 166·4 for the former and 289·1 for the latter. With 72 degrees of freedom for each group they differed from each other at the 1 % level ofP.4. Multiple correlation analyses were also done on the two groups of strains. It was concluded, all else being equal, that theF5strains over a period of years would be less liable to give low yields in a bad year than theF6strains.
The effect on nitrogen retention in lambs of feeding protein supplements direct to the abomasum. Comparisonof liquid and dry feeding and of various sources of protein
Authors: Ørskov E. R. , Fraser C. 
Published: March 2009

SummaryThree experiments were conducted to investigate the influence on nitrogen retention of feeding protein supplements to early weaned lambs direct to the abomasum via the oesophageal groove. In Exp. 1 the lambs received a basal diet of barley and a protein mixture consisting of soyabean meal, sunflower meal and fish meal which was given either in a liquid suspension from a bottle or as dry feed incorporated with the barley. The results showed that the regression coefficients of nitrogen retention on intake were 0.48 and 0.33 with liquid and dry feeding respectively. The regressions of urinary nitrogen on intake were with liquid and dry feeding respectively 0.26 and 0.44.In Exp. 2, various sources of protein were compared isonitrogenously as substitute for part of a barley concentrate ration. The nitrogen intakes and retentions were 14·28 and 5·09, 20·16 and 9·39, 20·53 and 8·19, 19·00 and 7·80, and 18·87 and 7·86 g/day for the control diet and fish meal, yeast, soyabean meal and sunflower meal supplemented diets respectively.In Exp. 3 the fish meal supplement was compared with a high lysine, bloodmeal and with casein as liquid supplements to a basal diet of barley concentrate. The intake and retention of nitrogen were for bloodmeal, casein and fish meal respectively 23·41 and 7·48, 22·56 and 9·11, and 21·88 and 8·31 g/day. It appeared that the protein sources high in methionine resulted in the highest nitrogen retention. The implications of these findings in relation to the nutrition of young ruminants is discussed together with an evaluation of the experimental method as a technique to study postruminal digestion.
Some observations on endogenous loss of calcium in the sheep
Authors: Field A. C. , Suttle N. F. 
Published: March 2009

SummaryEstimates of endogenous loss of calcium have been obtained from balance studies with growing lambs and adult sheep given diets containing deficient and adequate amounts of calcium and phosphorus. The values were generally lower than those obtained for sheep by methods employing radioactive calcium and it was concluded that the endogenous loss by sheep is considerably less than the figure used by the Agricultural Research Council (1965) and is probably of the same order as that of cattle (16 mg/day kg live weight).
Fleece shedding, staple length and fleece weight in experimental Wiltshire Horn-Scottish Blackface sheep crosses
Authors: Slee John 
Published: March 2009

1. A crossing experiment was carried out between two breeds of sheep: the Wiltshire Horn—a breed with a short-stapled fleece which is normally shed both in lambs and adults, and the Scottish Blackface—which has a long-stapled carpet type of fleece. Animals of F1, F2 and both backcross generations were studied for gross characteristics of the fleece.2. The influence of the Wiltshire genotype caused a high incidence of fleece-shedding animals amongst all the crosses. Three separate components of the shedding process were distinguished: (a) the ability to shed, (b) the extent of shedding—or proportion of the body area denuded, (c) the time of onset of shedding. Attributes (a) and (b) were determined genetically; control was probably on a multifactorial basis, although there may have been fewer genes involved than for the other characters studied. Given the genetically determined existence of (a) and (b), (c) was apparently controlled by the environment. Seasonal change in day length was postulated as a major operative factor.3. The mid-side staple length of Wiltshire crosses was less than that of the Blackface parents. The decrease resulted partly from shedding and partly also from a reduction in the average growth rate of some fibres. When corrected for shedding the mean staple lengths of the crosses were about equal to the values theoretically expected on the basis of multifactorial inheritance without directional dominance.4. The mean fleece weight of the Wiltshire crosses was less than that of the Blackface parents, due, about equally, to: (a) loss of wool by fleece shedding, (b) reduced wool production—probably caused, at least partly, by the decreased average growth rate of some of the component fibres of the fleece. Differences in wool production appeared to be inherited multifaetorially.
The availability of iron on certain grass, clover and herb species Part II. Alsike, broad red clover, kent wild white clover, trefoil and lucerne
Authors: Raven A. M. , Thompson A. 
Published: March 2009

1. The availability of iron in five species of legumes has been investigated, using the rat as the experimental animal.2. Two procedures were employed, namely, the increase in blood haemoglobin concentration, and the gain in total grams of haemoglobin, by nutritionally anaemic rats.3. Inorganic iron, as ferric chloride, was shown to be significantly more available than the iron contained in the five legumes.4. A significant difference in iron availability between alsike and wild white clover was obtained with both methods of expressing the results. Differences between other species were not significant.5. The data are compared with those obtained for three species of grass in an identical experiment reported previously.
Observations on the use of plasma free fatty acid concentrations in the determination of maintenance requirements of sheep
Authors: Russel A. J. F. , Doney J. M. 
Published: March 2009

SUMMARYThe objective of the investigations reported in this paper was to examine the possibility of using plasma free fatty acid concentrations as a means of estimating food requirements for maintenance purposes in sheep. Estimates derived in these investigations are considered to be less satisfactory than those based on live-weight change. It is concluded, however, that the technique merits further consideration, and that, with more precise knowledge of FFA concentrations in maintenance-fed sheep and of the FFA: food intake response curve, it could provide a useful alternative means of estimating maintenance requirements.
Body composition of young sheep: I. Body composition in merino and Border Leicester × Merino hoggets in relation to and at common empty body weight
Authors: Gharaybeh H. R. , McManus W. R. , Arnold G. W. , Dudzinski M. L. 
Published: March 2009

SUMMARYFlocks of 9-month-old Merino and Border Leicester & Merino sheep were sampled over the full range of body weights present within flocks. Six pairs of ewes and wethers of equal body weight were taken. The sheep were weighed and slaughtered after a 36 h fast. Total weights of blood, skin, head, feet, internal organs and carcasses were obtained for each animal. Each component was analysed for ash, crude protein, ether extract and total energy. Half of each carcass was dissected into bone, muscle, fat and waste.The compositions of the sheep were compared by regression analyses of weights of body components on empty body weight (EBW) between the four groups and by means of percentages of EBW. There were highly significant linear relationships between both fresh and dry weights of body components, carcass components, and chemical components with EBW; moisture content was not related to EBW. Rates of change with EBW in weights of body components, or in amounts of ash, crude protein, ether extract and energy were the same for all groups of sheep with the exceptions of bone and skin ether extract (EE) weight. However, intercepts of regression lines frequently differed, indicating that body composition differed between groups at the same EBW.All groups had the same dry weight of blood, internal organs and muscle, weight of ether extract, and total energy in the whole body at the same EBW. Border Leicester × Merinos had lighter skins with less wool, but their carcass weights were higher than Merinos. There were other differences between breeds in the chemical composition of individual components. Wethers had heavier head + feet weights and carcass bone than had ewes. There were also some sex differences in chemical composition of body components. In general, there were fewer sex than breed differences in body composition. The breed differences cannot be explained on the basis of early and later maturing types.
Heterosis and combining ability in hybrids ofAvena sativaL. andA. byzantinaC. Koch.
Authors: Jenkins G. 
Published: March 2009

SUMMARYThree varieties ofAvena byzantinaC. Koch., Sierra, Avon and Anita, originating respectively in California, Australia and South Africa, together with the Dutch variety Condor (A. sativaL.) were used as ‘subject’ varieties in crosses with a range of nine tester varieties of mainly north-west European origin. The results of a yield trial of spacedF1transplants and a drilledF2trial are presented.In theF1trial there was marked heterosis for grain yield, the thirty-six crosses yielding, on average, 109 % of the higher yielding parent, with individual cross values ranging from 68 to 139%. Heterosis was more marked insativa × byzantinacrosses than insativa × sativacrosses and the variety Sierra showed particularly high general combining ability. In theF2trial, heterosis was considerably reduced and the thirty-six crosses yielded, on average, only 96% of the higher yielding parent. In someF1crosses, heterosis for grain yield was accompanied by transgression of the higher yielding parent in number of panicles per unit area. The number of grains per panicle was positively correlated with grain yield in theF2trial but no heterosis was observed for this component. Grain size was negatively correlated with yield in theF2trial and heterosis for this component was observed in a few crosses in which yield heterosis occurred.Straw height was positively correlated with grain yield in theF1trial but negatively correlated in theF2trial. Crosses showing heterosis for yield exceeded the mid-parent but not the taller parent in straw height. The ratio of grain yield to straw yield was higher for the progenies of thebyzantinavarieties Sierra and Avon than for the progenies of thesativasubject Condor. Grain yield was positively correlated with number of days to 50% panicle emergence in both trials.It is concluded that theA. byzantinavarieties Sierra and Avon could, with advantage, be used for hybridization with adapted genotypes ofA. sativa, thereby enlarging the gene pool available to oat breeders in north-west Europe.
Effect of low skin surface temperature on wool growth
Authors: Downes A. M. , Hutchinson J. C. D. 
Published: March 2009

SUMMARYThe length of wool grown per day, on closely clipped patches of the skin of two sheep exposed to an ambient temperature of 2 °C for 4 days, was reduced to 30% of normal. For individual fibres, this decrease was directly proportional to their normal growth. Fibre diameter was not affected. Growth in a warm 4-day period succeeding the cold period returned to normal and remained normal thereafter.
The digestibility of oat hay
Authors: Walker H. F. 
Published: March 2009

1. Digestibility trials, using sheep, were carried out on five batches of oat hay grown during 2 years; nitrogen balance experiments were made simultaneously.2. The oat hay was not readily consumed by the sheep; this necessitated calculating the digestibility data on an ‘as consumed’ and on an ‘as offered’ basis; it also prevented a majority of the sheep from obtaining their maintenance requirements of energy or from maintaining nitrogen equilibrium.3. Statistical analysis of the data revealed a downward drift in digestibility in the succeeding periods of the 1955 trial.4. While stage of maturity had little consistent effect on digestibility or on the amounts of digestible nutrients present, the percentage digestible crude protein did increase with advance in maturity.5. The amounts of digestible nutrients present in oat hay indicated that it had a nutritive value between those of oat straw and medium-quality meadow hay.6. The data suggest that the maximum yield of digestible nutrients is obtained when the oat hay is cut at the ‘late cheesy’ stage of maturity.
The isolation of ‘pure lines’ fromF1hybrids of tomato, and the problem of heterosis in inbreeding crop species
Authors: Williams Watkin 
Published: March 2009

1. The problem of inbreeding and the fixation of apparent heterosis in the cultivated tomato and in inbreeding crop species generally is discussed. The case is argued that ‘heterosis’ as normally understood in out-breeders is not likely to exist as a general phenomenon in inbreeding species.2. Selections were made among segregating progenies of two successful, commercialF1hybrids, and the performance of the selected lines, up to theF4generation, shows that the superiority of the hybrids over their parents can be fixed in purebreeding lines.3. Owing to selection effects in inbreeding species of crops the best parents will differ in respect of fewer quantitative loci than is to be expected from general experiments on quantitative inheritance. In the present material, desirable recombinants were isolated at a frequency of 1 in every 1000–1500F2individuals.4. The utility ofF1hybrids in the tomato thus depends on the economy of effort involved in their development as compared with the isolation of pure lines. It is concluded that the production of hybrids is to be favoured only when reliable methods of prediction of their performance are available, and then as an interim measure while pure-line forms become available.
Grazing behaviour of calves reared at pasture
Authors: Chambers D. T. 
Published: March 2009

1. Observations were made on the behaviour of young spring- and autumn-bom calves reared at pasture.2. Bucket-fed calves rapidly learnt to graze, whereas single-suckled animals running with their dams made no serious attempt to graze until they were 6 weeks old.3. The time spent in grazing was modified by the presence of hay and probably by that of concentrates, and it was influenced also by the quality and quantity of herbage on offer.
The effect of plant spacing on grain yield of tall and short sorghum in Nigeria
Authors: Goldsworthy P. R. , Tayler R. S. 
Published: March 2009

SUMMARYThe grain yield, head structure and components of yield of a Nigerian long-season sorghum (Farafara) and an American hybrid short-season type (NK 300) were compared at three populations. The effect of thinning at initiation and at heading was also examined.At each population, the grain yield per plant of NK 300 was larger than that of Farafara, mainly due to differences in the number of grains per head. This factor was also the main one responsible for a decline in yield per plant with increase in population. At all populations, Farafara plants showed an appreciable increase in stem weight after heading.The results from the thinning treatments suggest that the main difference between the two varieties is in the number of spikelets present at head emergence: the number and/or potential size of developing grains in Farafara appeared to be largely determined by the time of initiation and was probably too small to accept all the currently produced assimilate.
The effect of wilting berseem and lucerne herbage on voluntary dry-matter intake by buffalo heifers
Authors: Yoelao K. , Jackson M. G. , Saran Ishwar 
Published: March 2009

SUMMARYTwo changeover experiments, each on eight buffalo heifers, were conducted in two different years to determine the effect of wilting lucerne herbage (Exps. 1 and 2) and berseem herbage (Exp. 2 only) on voluntary dry-matter intake. The dry-matter content of the herbages increased by field wilting from 27 to 50 and from 26 to 44% for lucerne in Exps. 1 and 2 respectively, and from 21 to 31% for berseem. The drymatter intake, nutrient digestibility coefficients, nutritive value index and retention time of undigested residues were determined for each fresh and wilted herbage.Wilting increased the dry-matter intake of lucerne from 2·3 to 2·8 and from 2·1 to 3·5 kg per 100 kg body weight in Exps. 1 and 2 respectively. Berseem dry-matter intake was increased from 2·2 to 3·1 kg per 100 kg body weight. Digestibility coefficients of all nutrients of both herbages increased by 6–20%. Retention times were unaffected by wilting. The nutritive value indices for lucerne and berseem in Exp. 2 increased by 160 and 60% respectively. In Exp. 2, the average loss of herbage dry matter due to wilting was 3·8%. The higher consumption of the wilted herbages is ascribed to their lower water content. The practical implications of these results are discussed.
Effects of experimentally produced local subdermal temperature changes on skin temperature and wool growth in the sheep
Authors: Lyne A. G. , Jolly M. , Hollis D. E. 
Published: March 2009

SUMMARYA heat-exchange chamber made of perspex was inserted beneath the skin of a Merino sheep. By passing water at predetermined temperatures through the chamber, the normal subdermal temperature of 37°C was raised approximately 4°C for 4 days, then lowered approximately 5°C for 4 days.In response to heating, the animal's temperature regulating mechanism was able to maintain a fairly constant subdermal temperature. However, it was unable to maintain as constant a subdermal temperature in response to cooling. There was, during the cooling period, an obvious nervous response to environmental disturbances manifested by sudden transient decreases in subdermal temperature over the chamber.During the cooling period there was a decrease of 12% in mean length growth rate of wool over the chamber but mean fibre diameter was unchanged. Heating produced a small decrease in mean fibre diameter, but no change in mean length growth rate. Heating appeared to produce a slight reduction in pigmentation of some fibres but neither heating nor cooling produced demonstrable changes in crimping.
The potassium Q/l relationships of soils given different K manuring
Authors: Addiscott T. M. 
Published: March 2009

SUMMARYThe potassium quantity/intensity (Q/I) relationships, which relate change in exchangeable K content (Q) to change in activity ratio were measured in soil samples from manuring experiments at Rothamsted and Woburn. Within each experiment, Q/I curves for different K-manuring treatments were super-imposable on each other and on the curve relating exchangeable K to Io, the activity ratio at which the soil neither gains nor loses K. The distances on the Q axis between the curves were equal to the differences in exchangeable K.The buffer capacity, dQ/dI, was related to the K saturation of the cation exchange capacity (CEC) by the equations(Q and CEC in m-equiv/100 g)Broadbalk and Hoosfield soil, andfor Barnfield soils (b= 3·08; m= 1·0) and for Woburn market garden soils (b =2·41; m= 0·6) but for soils from other Woburn experiments, dQ/dl did not vary significantly with Q/CEC.
Urinary phosphate excretion in the dairy cow
Authors: Manston R. , Vagg M. J. 
Published: March 2009

SUMMARYAnalyses of cow urine showed that about 10% of housed cows excreted phosphate greatly in excess of ‘normal’. The phosphaturia only occurred when the cows were permanently housed. No high phosphate concentrations were found in. urines from grazing cows although a significant increase in phosphate concentrations occurred when these cows were temporarily transferred to housed conditions.No significant differences were detected between the high and low phosphate excreting cows with respect of urinary concentrations of creatinine, calcium, or chloride, urine specific gravity or pH, or plasma concentrations of calcium, inorganic phosphate, magnesium, sodium, potassium, alkaline phosphatase, chloride or bicarbonate.Complete phosphorus balance measurements on four cows during the last six weeks of pregnancy showed that an increase in urinary phosphate excretion occurred in both high- and low-phosphate excreting cows when a dietary 'steaming-up' schedule was employed, and that the phosphaturia was accompanied by an increase in absorption of dietary phosphorus.The cause of the phosphaturia does not appear to be acidosis. Little change in urinary phosphorus excretion occurred after oral doses of ammonium chloride but some increase occurred after equivalent doses of sodium and potassium carbonates. It is concluded that a small proportion of cows have a tendency to excrete relatively large amounts of phosphorus in the urine but that this only occurs under housed conditions.