bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of different protein contents in the rations of growing-fattening pigs
Authors: Braude R. , Townsend M. Jill , Harrington G. , Rowell J. G. 
Published: March 2009

1. A co-ordinated trial has been carried out at eighteen centres to study the effects of feeding various quantities of high-protein supplement to growing-fattening pigs. In treatment 1, 10% white fish meal was included from weaning to 150 lb. live weight and 3% soya-bean meal was included from 150 lb. live weight to slaughter (approximately 210 lb.). Treatment 2 was the same as treatment 1 except that only 7% white fish meal was included during the first stage. Treatment 3 was the same as treatment 2 except that the rations were changed at 1001b. live weight instead of 1501b. Treatment 4 was the same as treatment 3 except that highprotein supplement was omitted altogether after 1501b. live weight; thus there were three rations involved in treatment 4—7% white fish meal from weaning to 100 lb. live weight, 3% soya-bean meal from 100 lb. to 150 lb. and no high-protein supplement thereafter.2. Growth rate and feed conversion both differed significantly between treatments. Pigs on treatment 1 grew 5·0% faster than those on treatment 4; the average growth rate for treatments 2 and 3, the difference between which was negligible, was 3·3% higher than for treatment 4. Feed conversion for treatment 1 was 5·4% better than for treatment 4 and the average for treatments 2 and 3 was 3·8% better than for treatment 4.3. Treatment differences were not significant for killing-out percentage, length, quality of fat, proportions of gammon, middle and fore-end of the cured side, thickness of streak, size of eye muscle and amount of fat over it. Some of the fat measurements differed significantly between treatments; differences in fat thickness at the shoulder, middle and rump between treatments 1, 2 and 3 were generally small, but the lowest protein level (treatment 4) resulted in carcasses with about 2% more fat along the back than the average of treatments 1, 2 and 3. These slight differences in back-fat thickness did not result in significant differences in the percentage of pigs in the highest grades.4. An economic appraisal of the results suggested that under the conditions prevailing at the time of the experiment treatment 3 would have resulted in the greatest profit per year, and the greatest profit per pig. This ration was relatively cheap compared with those of treatments 1 and 2 but it did not lead to a seriously impaired performance, as did that of treatment 4, the cheapest ration.
Experimental design for grazing trials
Authors: Conniffe D. , Browne D. , Walshe M. J. 
Published: March 2009

SUMMARYAnimal production in grazing experiments depends both on treatment and on stocking rate. Production at optimum stocking rate is the only valid measure of treatment effect and treatment comparisons should be based on this criterion. Since optimum stocking rates are unknown these comparisons cannot be made directly, instead they must be inferred from the results obtained with the stocking rates actually used. This requires that some form of production stocking rate relationship be postulated. This paper suggests a form for this relationship and considers its implications on experimental design and particularly on the number of stocking rates per treatment.
The growth of vining peas
Authors: Meadley J. T. , Milbourn G. M. 
Published: March 2009

SummaryWhen incoming radiation was reduced artificially to 50% daylight during the postflowering period in peas, the rate of abscission of flowers and pods increased in the same way as when the density of planting is raised. Shading from flowering onwards reduced yield almost to the level of peas that were shaded throughout the growing season, even though peas that received full daylight until flowering had many fertile tillers and a greater reproductive potential in terms of the total number of flowers produced. Conversely, when shades were removed at flowering time the crop was able to compensate and yields approached those of peas grown entirely in full daylight, this was mainly due to a reduction in absoission losses of flowers and pods so that the majority of pods formed on the main stem contributed to final yield.It is suggested from these results that the major source of dry matter for pea yield is the photosynthate produced during the post-flowering period rather than that translocated from roots or stems following storage during the vegetative period.
Post partum conception in lactating Awassi and East Friesian × Awassi dairy ewes
Authors: Morag M. , Eyal E. 
Published: March 2009

SummaryTwo attempts were made to increase the number of lamb crops in intensively managed dairy sheep flocks. Rams were introduced into the flocks for the first 100 days after lambing. The ewes were milked twice daily from parturition. In the first flock of 188 ewes, the lambs were weaned at birth. Half the ewes received a course of progesterone and PMS in the third week post partum. 49% of the treated ewes conceived at average of 49 days post partum, and 59% of the non-treated ewes at an average of 53 days post partum. The hormone treatment reduced milk yield by 17% in the ewes which conceived and by 26% in those which did not conceive. Milk yield was 7% lower in those ewes which conceived a second time. Yield in the subsequent lactation was very low. In the second flock, the lambs of 83 ewes were weaned 40 days after lambing. 89% of the sheep conceived at an average of 64 days after lambing. The pregnant ewes yielded 6% less milk than those ewes which did not conceive. Yield in the following lactation was satisfactory. The practical implications of the results in terms of the possibilities of future production in dairy flocks are discussed.
Total protein and immunoglobulin concentrations in sera from 2-day-old Finnish Landrace × Dorset Horn lambs
Authors: Halliday R. 
Published: March 2009

SummaryImmunoglobulin concentrations in 2-day-old Finnish Landrace × Dorset Horn lambs were remarkably high and uniform and were unrelated to litter size. The mean concentrations in singles, twins, triplets and quadruplets were 2.95 ± 0.215, 2.95 ± 0.099, 2.94 ± 0.105 and 3.03 ± 0.142 g/100 ml respectively.
Some observations on the high level copper supplementation of pig rations
Authors: Fagan V. J. , Iles R. D. , Slowitsky Z. , Brocksopp R. E. 
Published: March 2009

1. Ten experiments are reported in which the effect of high-level copper supplementation of pig rations on growth rate and food conversion was observed. In three of the experiments the study included observations on carcass quality.2. In nine of the ten experiments a positive increase in the growth rate of the pigs receiving copper was recorded but the magnitude of this increase was markedly variable.
Environmental and genetic effects upon reproductive growth in tall fescue (Festuca arundinaceaSchreb.)
Authors: Bean E. W. 
Published: March 2009

SUMMARYThe environmental and genetic control of reproductive growth was studied in S. 170 a variety ofFestuca arundinaceaSchreb. The variety had induction requirements for short days and low temperatures before inflorescence production could occur, but some genotypes became induced with only short-day treatments. Low temperatures and short days in controlled environment rooms were less effective in bringing about induction than winter conditions in an unheated glasshouse. Only non-additive genetic effects could be shown to be significant in the control of induction requirements. Field studies showed that all inflorescence characters were subject to genetic and genetic x environmental control, and they also indicated that seed weight per inflorescence and seed fertility were most likely to show a response to selection. Diallel analysis under glasshouse conditions showed that the seed fertility and 1000 seed weight of the parental crosses were subject to maternal control, but these effects were not detectable in the next generation. Genetic control of seed fertility and 1000 seed weight in the diallel progeny was mainly additive.
Subjective assessment of body fat in live sheep
Authors: Russel A. J. F. , Doney J. M. , Gunn R. G. 
Published: March 2009

SUMMARYSubjectively assessed body condition scores, determined on the live animal, were related to the percentages of chemical fat in the fleece-free empty bodies of 30 adult Scottish Blackface ewes. The results show that body condition scores can provide an acceptable and useful estimate of the proportion of fat in the live animal, and that the level of prediction is superior to that afforded by live weight.
An analysis of the growth of inbred progeny ofLolium
Authors: Bean E. W. , Yok-Hwa Chen 
Published: March 2009

SUMMARYThe growth of the progeny from self-pollination was studied in seven cultivars ofLolium perenneand five cultivars ofLolium multiflorum. All cultivarsotLolium perenneshowed a reduction in the dry weight of the selfed progeny after one generation of inbreeding, although only four of these attained statistical significance. By contrast the reduction inLolium multiflorumwas less marked with only one cultivar showing a significant reduction on inbreeding. An analysis of the growth of two of theLolium perennecultivars which showed reduced vigour in progeny from self-pollination suggested that a lower germination rate and a slower development of leaves in the seedling were two factors which resulted in reduced weights in inbred progeny. The possible effect of the environment in which the inbreds were produced on seedling performance is discussed.
The effect of level of intake and free fatty acid content on the metabolizable energy value and net absorption of tallow by the laying hen
Authors: Shannon D. W. F. 
Published: March 2009

SUMMARYThe metabolizable energy (ME) values and net absorption of tallows containing 20, 40, 60, 80 or 98% free fatty acids were determined using mature laying hens. By restricting food intake, the intake of the tallows was controlled to 3, 5, 10 or 20 g per bird d. The tallows were added to a diet of known ME content and the ME's of the tallows were calculated from the data collected from 6- or 7-day energy balances.ME and net absorption values of the tallows were significantly (P < 0·001) lowered when the level of intake was increased from 3 to 20 g/bird d. The values were also significantly (P < 0·001) lowered when the free fatty acid content was increased from 20 to 98%. The effects of free fatty acid level (F) and level of intake (L) on the ME and net absorption values were considered in terms of curved surfaces represented by equations embracing the factors and their product. The equations obtained were:ME(kcal/g) = 8·745 – 0·004F – 0–361 log10L–0·011 F log10L,Net absorption (%) = 95·82 + 0·02F – 4·65 log10L – 0.13F log10L.
The analysis and prediction of some two factor interactions in grass breeding
Authors: Wright A. J. 
Published: March 2009

SUMMARYA method of analysis of two factor experiments is given. This involves a development of the regression analysis used by Finlay & Wilkinson (1963) and others, and allows for the regression of interaction components onto both main effects. The usefulness of the single joint regression parameter for prediction is outlined.The applicability of the analysis to three situations commonly found in grass breeding is illustrated by means of examples. It is concluded that the model may frequently describe variation due to genotype-environment interactions, and among diallel arrangements of binary mixtures of genotypes, but is likely to be of little utility for genetic diallel or other mating schemes unless the genes have a strongly correlated distribution among the parent plants.
Changes associated with pregnancy and lactation in some extra–reproductive organs of the ewe
Authors: Fell B. F. , Campbell Rosa M. , Mackie W. S. , Weekes T. E. C. 
Published: March 2009

SUMMARYThe food intake, the apparent digestibilities of dry matter, and of nitrogen were measured in housed Blackface ewes during late pregnancy, lactation, and after the lambs were weaned. The ewes were slaughtered serially together with non-breeding controls, and the liver, ruminal mucosa, intestines, CNS and carcass were weighed. In association with differing reproductive status marked changes occurred in the content of dry matter and protein in the alimentary organs, but not in the CNS, and the mean weight of DNA in the CNS for all the animals was 130 ± 20 (S.D.) mg.All of the alimentary organs became hypertrophied during lactation, and regressed after weaning. Maximum values for the liver and ruminal mucosa occurred in the sixth week of lactation, and were maintained until weaning. The small intestine reached maximum weight after 4 weeks of lactation.
Effects of pregnancy and lactation on the activities of some gluconeogenic and urea-cycle enzymes in sheep liver
Authors: Mackie W. S. , Campbell Rosa M. 
Published: March 2009

SUMMARYThe effect of reproductive state on the activity in sheep liver of the gluconeogenic enzymes glucose-6-phosphatase and fructose-1,6-diphosphatase, and of the urea cycle enzymes arginase and the arginine synthetase system, was investigated. The sheep were Blackface ewes that were killed during pregnancy, lactation and after the lambs were weaned, together with non-breeding controls.The total activities in the liver of glucose-6-phosphatase, and of arginase, fell during pregnancy and rose during lactation in proportion to liver hypertrophy, reaching maximum values late in lactation.In breeding ewes total hepatic fructose-l,6-diphosphatase activity differed little from that in the controls except in the period 14 days before to 13 days after parturition, during which the activity was 10 times higher than at other times. The arginine synthetase system declined in activity during late pregnancy. There were 2 peaks in activity after parturition, one at 30 dayspost partumand one at 30 days after the lambs were weaned. The peaks possibly were associated with periods of resorption of maternal proteins.
A source of error in the estimation of the organic matter content of samples containing calcium carbonate
Authors: Hovell F. D. DeB. , Ørskov E. R. 
Published: March 2009

The conventional method for the determination of the organic matter content of diets and faeces is by ashing the sample at 550 °C (A.O.A.C, 1965)Organic matter (O.M.) = dry matter (D.M.)–ash.If the sample contains calcium carbonate, then some of this carbonate will be converted to oxide (Vogel, 1951) and the weight of carbon dioxide evolved will be calculated as organic matter. The amount of carbonate converted will be dependent upon the temperature at which the sample is ashed and the duration of the ashing process. We have found (Ørskov, Hovell & Allen, 1966; Hovell & Greenhalgh, 1972) that when calcium salts of volatile fatty acids are included in diets given to sheep, most of the calcium is excreted in the faeces as carbonate, and since apparent digestibility is the difference between the amounts of nutrient ingested and excreted, the estimation of the apparent digestibility of organic matter will be in error if no correction is made for the high calcium carbonate content of the faeces. For example, a diet which contained 9·2% of calcium acetate had a true organic matterapparent digestibility of 86·8%. Had no correction been made this would have been estimated as 84·9%.
Prediction of the body composition of live cattle
Authors: Little D. A. , Morris J. G. 
Published: March 2009

SUMMARYTwo methods of determining body composition in live cattle have been compared with the composition of the cattle as determined by chemical analysis. Total body water (TBW) was estimated from tritiated water (TOH) dilution, and circulating redcell volume (RCV) estimated from measurements of plasma volume and haematocrit. TBW was very closely related to fat-free weight and fat weight as a percentage of live weight (LW) in eight cattle ranging from 3 to 34% fat. TOH space was more precise than RCV in the estimation of the various chemical fractions of the live animal.TOH injected intravenously equilibrated with ruminal water in 8–10 h; one could be confident that equilibration had occurred 10 h after injection, and equilibration time was not affected by previous restriction of feed and water. The mean biological half life of TOH was 4·2 ± 0·4 days. Equations are presented for the practical determination of the various compartments.
The effect of interval between harvests and nitrogen application on the numbers and weights of tillers and leaves in four ryegrass varieties
Authors: Wilman D. , Koocheki A. , Lwoga A. B. , Droushiotis D. , Shim J. S. 
Published: March 2009

SummaryThe effect of six intervals between harvests and three levels of N application on the number of tillers was studied in four ryegrass (Lolium) varieties in the first harvest year and in two varieties in the second and part of the third harvest years in a field experiment. Weight/tiller was recorded in the first 2 years and weight/green leaf and number of green leaves harvested were recorded in the first year.There was a large negative interaction between level of N and interval between harvests in respect of number of tillers, the number being increased by N with short intervals and tending to be reduced by N with long intervals. The interaction was larger in the second and third years than in the first. The negative interaction in respect of number of tillers and number of green leaves harvested was associated with a reduction in the percentage increase in yields of dry matter, digestible organic matter and N due to the application of N as the interval was increased. It is suggested that one should in general avoid a combination of high N and long intervals between harvests with present varieties of perennial ryegrass.The effects of interval between harvests, N application, variety and time of year on number of tillers and weight/tiller are discussed in relation to their effects on yield to show how tiller information can contribute to a better understanding of the ways in which yields are achieved. Rather low yields in the late summer and early autumn of the second harvest year were in many instances attributable to a rather low number of tillers rather than to low weight/tiller.There was a considerable increase in number of tillers between the end of one growing season and the early part of the next, suggesting that the period in which this increase is achieved may be an important one in relation to the continued vigour of the sown species.A reduction in annual yield of green leaf with extension of interval from 6 to 10 weeks with N applied resulted from a reduction in the number of green leaves harvested/harvest and in the number of harvests, which outweighed an increase in number of green leaves harvested/tiller and in weight/green leaf. Increasing the level of N with intervals of 3–6 weeks increased the number of tillers, the number of green leaves harvested per tiller and per unit area of ground and weight/green leaf and hence consistently increased green leaf yield.
Yield potential in a dwarf spring wheat and response to crop thinning
Authors: Fischer R. A. , Laing D. R. 
Published: March 2009

SummaryExperiments with wheat describing the effects of crop thinning on grain yield and its components are presented. These were carried out over 5 years in northwest Mexico, using a high-yielding dwarf spring-wheat variety (Triticum aestivumcv. ‘Yecora 70’) grown under irrigation and high fertility. It was shown that thinning largely relieved competition for light, thus increasing photosynthate levels in the plants remaining after thinning. The objective was to evaluate this simple technique as a guide to understanding when grain yield and its components were determined and, in particular, the extent to which post-anthesis photosynthate supply limited yield.There were major responses in grain yield with thinning between about 50 and 100 days after seeding, and in number of spikes and of grains with thinning between 50 and 90 days (50% anthesis was reached at 87 days). Number of spikelets per spike showed small responses to early thinning (before 50 days). Number of grains/spikelet and kernel weight snowed positive responses to thinning between 65 and 90 days, and 90 and 115 days, respectively. These results agreed with adjacent shading and CO2fertilization studies but, because of certain difficulties in interpretation of responses, pre-anthesis thinning was not considered a very useful technique.Anthesis thinning was carried out on 21 separate crops: the kernel weight increase relative to the unthinned control ranged from 6 to 41%, averaging 20%. Anthesis thinning led to increases in stem weight during the first half of the grain filling period, followed by increases in grain growth rate in the latter half. The increase in final kernel weight was greater with higher temperature and lower radiation during grain filling; these variables explained 64% of the variation in kernel weight response. It is suggested that the kernel weight response does indicate the degree of photosynthate limitation during grain filling, showing reasonable agreement with adjacent shading and CO2fertilization studies. It was concluded that anthesis thinning, because of its relative simplicity, is a useful technique. Implications for yield improvement in Yecora of the results provided by this technique are discussed.
A comparison of the effect of straw incorporation and CO2 enrichment on the growth, nitrogen fixation and yield of soya beans
Authors: Shivashankar K. , Vlassak K. , Livens J. 
Published: March 2009

SUMMARYIn a glasshouse pot culture experiment, the effect of adding straw at 3 and 6 t/ha with and without CO2 enrichment treatments at 1000 mg/1 from flowering to the pod-filling stage in open top chambers was evaluated on the growth and yield of soya beans in relation to nitrogen fixation. N2-ase activity of the soya-bean root nodules as determined by the acetylene reduction technique indicated that (1) straw on average gave significantly 34 and 43% higher N2-ase activity at 3 and 6 t/ha respectively than the controls; (2) CO2 treatments on average increased the activity by 34% compared with the no CO2 treatments; and (3) the mean N2-ase activity nearly doubled from 9·7 μg/h/plant in the control to 18·7 and 19·7 μg/h/plant with straw incorporation in conjunction with CO2 enrichment. High correlations were observed between weight of nodules and dry weight of leaves, between dry weight of nodules and grain yield and between dry weight of leaves and grain yield. Incorporation of straw was found to be beneficial in increasing CO2 content of soil air and in improving the growth and development of the plants. This study lends support to a hypothesis that straw can be considered to provide a partial substitute for the expensive CO2 enrichment treatment for improving N2(C2H2) fixation capacity and thereby the general growth and yield of crops.
Effect of the amount and form of roughage in the diet on digestibility of whole maize grain in cows and steers
Authors: Nordin M. , Campling R. C. 
Published: March 2009

SUMMARYFour experiments investigated some of the factors affecting the digestion of whole maize grain in non-lactating cows and yearling steers. With steers, but not cows, maize in diets containing small amounts of hay (14%) and large amounts of whole grain were better digested than those with 37 or 48% hay. The higher digestibility of maize in steers was associated with a greater time spent ruminating per kg feed and a longer retention time of maize in the gut than in cows. Replacing long roughage with ground and pelleted roughage in diets for steers improved the digestion of whole maize but not as well as reducing the hay to 14% of the diet. Finely grinding the maize produced a large increase in digestibility of the feed in cows and steers and both digested it to the same extent. It was concluded that the motility of the reticulo-rumen during eating and ruminating largely determines the extent of the digestion of whole maize grain.