bluuebunny/crossref_metadata_2025_split huggingface dataset:
Milk production in the Latin-American Milking Criollo and its crosses with the Jersey
Authors: de Alba J. , Kennedy B. W. 
Published: September 2010

ABSTRACTAn analysis was conducted on milk production data collected from 1954 to 1981 at Turrialba, Costa Rica. The local conditions are humid and tropical without a sharply defined dry season. The data included purebred Central American Milking Criollos, Jerseys, their reciprocal F, crosses and backcrosses. Two data sets were created: one with minimum restrictions intended to include production data from all calvings, and another data set intended to include only lactations with normal let-down without the presence of the calf. Data were analysed by maximum likelihood according to a model that included the fixed effects of year of calving, parity of lactation, breed or cross and the regression on year of birth of the sire's first daughter and random effects of sire, cow and error. Breed or cross differences were significant for milk yield, fat-corrected milk (FCM) yield and lactation length but were not significant for fat concentration.F1 crosses were superior to both parental breeds for milk and FCM yields for both data sets; there were no significant reciprocal effects. The ¾ Criollo backcross had significantly lower milk and FCM yields and shorter lactations than did the F1 or ¾ Jersey. These results suggest that breeding programmes for this type of environment should backcross F1's to Jersey sires and use criss-crossing from then on. The proportion of heterosis for milk, FCM, butterfat concentration and lactation length was 0·26, 0·28 0·02 and 0·15 for minimum-restriction lactations and 0·21, 0·22, 0·01 and 0·09 for normal lactations. Heritabilities for milk, FCM, fat concentration and length of lactation were 0·44, 0·42, 0·28 and 0·41 for minimum restriction lactations and 0·28, 0·27, 0·35 and 0·08 for normal lactations. The relatively higher values for minimum-restriction records suggest a strong genetic effect on ease or difficulty of milk let-down.
Growth and carcass composition of pre-pubertal dairy heifers treated with bovine growth hormone
Authors: Sandles L. D. , Peel C. J. 
Published: September 2010

ABSTRACTThe effects of long-term administration of exogenous growth hormone (GH) on growth and carcass composition of pasture-fed, pre-pubertal dairy heifers were examined. Purified bovine GH (specific activity, 0·78 i.u. per mg) was administered daily for 21 weeks (0·6 mg GH per kg M0·75) to one member of each of 12 sets of twins. GH administration resulted in a significantly higher growth rate (0·58 kg/ day) compared with the control group (0·54 kg/day) and produced a heavier carcass (75·6 kg v. 69·5 kg). However, this production gain did not persist when GH treatment ceased. Plasma metabolite concentrations and carcass composition were not affected by GH treatment. GH tended to increase slightly the voluntary intake of freshly cut herbage dry matter (3·5 kg/day v. 3·7 kg/day; P < 0·05), but had no effect on food conversion efficiency. Serum somatomedin levels were not significantly increased by GH during week 13 of treatment. This experiment indicates that pre-pubertal heifers chronically treated with GH will increase their food intake to sustain an increased rate of growth. However, the production gains made over the treatment period were transient and within 5 weeks of the cessation of GH treatment there was no difference in the live weight of the two groups.
The milk yield and milk composition of the Greek indigenous goat (Capra prisca) as influenced by duration of suckling period
Authors: Zygoyiannis D. 
Published: September 2010

ABSTRACTTwo groups, A and B, each consisting of 12 Greek indigenous goats suckling single kids were traditionally fed during a 36-week lactation period. During the suckling period (6 and 12 weeks for the groups A and B, respectively) milk production was estimated at 7-day intervals. During the milking period (30 and 24 weeks for the groups A and B, respectively) the goats were hand milked twice daily and their milk production was measured at intervals of 4 weeks. Milk samples were analysed for fat, protein, lactose, ash and dry matter concentration. Solids-not-fat and energy concentration were calculated. During lactation the goats were weighed weekly up to week 12 and monthly thereafter and body condition score was assessed at each weighing.Goats with a 6-week suckling period produced significantly less milk throughout lactation but significantly more marketable milk than those with a 12-week suckling period. Yield peaked at the 6th and 10th weeks of lactation respectively, then declined rapidly and tailed off gradually from weeks 7 and 16 respectively. Milk composition was affected only occasionally by the duration of the suckling period. Thus, fat concentration was higher for the group with the 6-week suckling period between weeks 7 and 16, whilst protein was higher between weeks 8 and 12. Lactose concentration was lower for the same group between weeks 7 and 11, whilst ash concentration was similar in both groups. Live weight and body condition of the goats throughout lactation showed similar changes in both treatment groups.
Optimum selection procedures in animal breeding
Authors: Smith Charles 
Published: September 2010

SUMMARYA simple expression relating the standardized selection differential (i) to the intensity of selection (p) is given byi≏0·8+0·41 ln (R−1)where R equals 1/p. This linear expression may allow simpler solutions to some optimization problems in selection than does the conventional formula for selection differential on truncation of the normal curve.Using the expression, formulae for the maximum immediate response and optimum selection intensity in mass selection have been developed, taking account of the loss in performance through inbreeding. These formulae were used to study the effect on response of the total number of animals tested. The maximum response over a specified period of time, allowing for the loss in genetic variance from inbreeding, has also been considered. The optimum intensity of selection may then be well below that necessary for the maximum immediate response.
The rumen pathology of intensively managed beef cattle
Authors: Rowland A. C. , Wieser M. F. , Preston T. R. 
Published: September 2010

SUMMARYHistological examination of the rumen wall in intensively managed beef cattle confirmed the superficial nature of many of the lesions present and failed to reveal evidence of secondary bacterial infection. Of the lesions described, only intra-mucosal abscesses and their subsequent erosions proved to be significantly related to the occurrence of hyperkeratosis of the rumen mucosa. The remaining lesions, vacuolation of the stratum granulosum, acute microscopic ulceration, congestion of the submucosa and the presence of leucocyte aggregations in the submucosa, were all independent of this hyperkeratosis.
The control of voluntary food intake in ruminants
Authors: Owen J. B. , Davies D. A. R. , Ridgman W. J. 
Published: September 2010

SUMMARYAn experiment to test the effect on the voluntary food intake of lambs of giving diets containing 0, 20, 40 and 60% of either coarse or finely ground oat husks, in either a loose or pelleted form, is described and the results discussed. The results showed that voluntary intake was uniformly depressed with increased dilution of the diet with oat husks when the oat husks were coarse and the diet given loose. However, when the oat husks were finely ground and when the diet was pelleted the response to dilution was much modified and in the case of older, heavier lambs intake initially increased with dilution. It is concluded that ruminants may sometimes be able to respond to increased diet dilution so as to maintain their maximum digestible-energy intake but that the attempt is often thwarted to varying degrees according to the physical form of the food. An hypothesis is suggested for the pattern of response in food intake to be expected according to the type of food given.
A note on the effect of amino acid or urea supplements to barley diets for the finishing pig
Authors: Hintz H. F. , Pond W. G. , Visek W. J. 
Published: September 2010

SUMMARYIn trials 1 and 2, supplements of urea and cottonseed meal increased the protein content of the basal diets from 12·2 to 14·0–14·6%, but had no significant effects on growth rate or carcass characteristics. In trial 3 the effect of cottonseed meal on growth rate was almost significant but urea had less effect. In trial 4, the basal diet contained 11·0% protein; soya bean meal increased this to 13·1% and had an almost significant effect on growth rate. Lysine and lysine + urea had no effect.
Studies on the nutrition of ruminants: 5. The effect of diets containing up to 70% ground barley straw on the live-weight gain and carcass composition of yearling Friesian cattle
Authors: Swan H. , Lamming G. E. 
Published: September 2010

SUMMARY1. Three groups, each of eight steers, were fed on pelleted diets containing 30, 50 or 70% ground barley straw, maize and soya bean meal. On an air-dry basis the diets contained 12% crude protein.2. Daily live-weight gain was 1·29, 1·19 and 1·02 kg/day for the 30, 50 and 70% straw diets respectively, and was negatively related to the percentage of crude fibre in the dry matter (r = −0·61, P < 0·05).3. The apparent digestibility of dry matter, determined in sheep at the maintenance level of feeding was negatively related to percentage crude fibre in the dry matter (r = −0·91, P < 0·001).4. All animals were killed at approximately the same live weight, which was reached on average in 140,153 and 163 days by the 30, 50 and 70% groups, respectively.5. The differences in mean carcass weight between treatments were significant (P < 0·05). Killing-out percentage was significantly reduced (P < 0·05) as the proportion of ground barley straw in the diet was increased from 30 to 70%.6. The proportion of straw in the diet had no direct effect on the composition of carcass gain.7. The results are discussed in relation to the intake of digestible energy.
Photoperiodism in the ewe: 1. The effect of long supplemented daylengths on the breeding activity of pregnant and non-pregnant Teeswater-Clun ewes
Authors: Ducker M. J. , Thwaites C. J. , Bowman J. C. 
Published: September 2010

SUMMARYDaylengths of 13 or 20 hr were applied to six groups of nine ewes during the 2nd to 8th, 8th to 14th and 14th to 20th week of pregnancy. Two groups of nine non-pregnant ewes received a constant 13- or 20-hr daylength during the above experimental period. A group of 10 non-pregnant ewes which initially received a 20-hr daylength were subjected to a 13-hr daylength in the last 14 to 20 weeks of the experimental period. After parturition (26 March) all the ewes received increasing natural daylength.The mean number of days from the onset of the experimental light treatments (17 November) to the cessation of oestrous activity did not vary significantly between the three non-pregnant groups of ewes and was on average 89 days.Only two of the 82 ewes, both non-pregnant, exhibited oestrus prior to the longest day (22 June). The various light treatments did not significantly affect the mean dates of occurrence of the natural breeding season of the groups of ewes.
A note on a Urea feeding experiment with sheep in Iran
Authors: Sarif-Sarban M. , Menke K. H. 
Published: September 2010

SUMMARYFour groups of 50 sheep were given rations containing barley, dried beet-pulp, wet beet-pulp silage, lucerne hay and straw, with A, no protein supplement; B, 1·6% urea; C, 21% Rumevite (supplying 1·3% urea); and D, 15% cottonseed cake. Average daily gains in body weight were 143, 187, 190 and 189 g for groups A to D respectively. Undernourishment and infection with endoparasites did not affect adaptation to urea.
Nutrition of the early-weaned calf. XI. Intake of diets differing in energy concentration
Authors: Kay M. , MacLeod N. A. , McLaren Margaret 
Published: September 2010

SUMMARY1. A growth and digestibility trial was carried out with 27 British Friesian calves given diets having either 3·1, 2·8 or 2·4 Meal metabolizable energy per kg dry matter and either the same concentration of protein or the same protein-to-energy ratio.2. Daily dry-matter intake and rate of gain in live weight increased significantly as the energy concentration of the diet was reduced. There were no significant differences in digestible-energy intake between calves given the different diets, although the trend was the same as for dry-matter intake.3. Both dry-matter digestibility and energy digestibility were lowest for the low-energy diet.
The performance of two breeds given different amounts and sources of protein in a high-molasses diet
Authors: Preston T. R. , Willis M. B. , Elías A. 
Published: September 2010

SUMMARYOn a fattening diet in which final molasses supplied from 68 to 76% of the metabolizable energy and napier grass some 10%, the treatments in a 2 × 2 × 3 factorial design were breed (Brahman or Brown Swiss × Brahman), source of supplementary protein (fish meal or poultry waste) and protein level (low, medium or high—replacing urea). Mean daily gains to 404 kg live weight were better for the crossbreds (0·89 compared with 0·77 kg), as was conversion rate in terms of Meal ME per kg gain (25·6 compared with 29·5); fish meal improved gains by 44% and conversion rate by 39% as compared with poultry waste when the two supplements were fed at levels designed to equate N intakes from this source. The superiority of the crossbreds was only apparent on the fish meal diets where they averaged 1·19 compared with 0·94 kg/day for the Brahmans. Daily N × 6·25 intakes decreased from 3·8 g/kg live weight on the low level of poultry waste to 2·9 on the high level due to low palatability of this material. On this treatment (poultry waste), daily gain (kg) was significantly related (b = 0·119±0·031; P<0·01) to N×6·25 intake (g) per unit live weight (kg). Commercial half carcass dissection showed the crossbreds to have significantly more edible meat, more bone and less e×cess fat than Brahmans. Protein source had no effect on carcass composition.
Responses in milk yield and composition to the inclusion of ammonium salts of short-chain fatty acids in the drinking water of dairy cows
Authors: Jackson P. , Rook J. A. F. 
Published: September 2010

SUMMARYThe effect of introducing a solution of fatty acids (consisting mainly of ammonium acetate) into the drinking water of Jersey and Friesian cows on the yield and composition of milk was investigated. In short-term experiments there were small increases in milk yield and in the yield of fat in Jersey cows receiving either a high-roughage or a high-concentrate diet and in Friesian cows receiving a high-concentrate diet. Friesian cows receiving a high-roughage diet gave no response. In a long-term experiment extending over 16 weeks of lactation with Jersey cows receiving a high-concentrate diet, there was no immediate effect on milk yield but a greater persistency and overall the yield of fat was increased by 5·9%.Inclusion of ammonia salts in the drinking water caused increases in the ammonia contents of rumen liquor and of blood but there was little effect on rumen pH or the volatile fatty acids of rumen liquor.
A note on the variation and heritability of twinning in British Friesian cattle
Authors: Bowman J. C. , Frood I. J. M. , Wood P. D. P. 
Published: September 2010

SUMMARYRecords of calving, excluding first calving, on 2862 cows, the daughters of 63 bulls used in AI were analysed to estimate the incidence and variation of twinning between bull progeny groups. The mean incidence of twinning was 2·8% and though the incidence increased with later parities the effect of parity was not significant. The incidence for bull progeny groups ranged from 0 to 8·8%. The intraclass correlation between parities for cows within bulls was 0·064±0·018 and a sire half sib group estimate of heritability for twinning, based on a single calving, was 0·43±0·012.
The induction of pregnancy during lactation in the sow: the effects of a treatment imposed at 21 days of lactation
Authors: Crighton D. B. 
Published: September 2010

SUMMARY1. Experiments carried out in two herds to examine the effects of a treatment designed to induce oestrus and ovulation during the lactational anoestrus of the sow and to allow the establishment of pregnancy during lactation are described. Two aspects are examined: (a) the effects on the reproductive performance of the sow of repetition of the treatment in successive lactations and (b) the effects of the treatment on the suckled young.2. The treatment involved the separation of each sow and litter for 12 hr on days 21, 22 and 23 of lactation followed by an injection of 1500 IU pregnant mare serum gonadotrophin (PMSG) at the end of the third period of separation.3. It is concluded that oestrus and ovulation can be induced with some consistency in the fourth week of lactation, that lactation is not incompatible with the first two to three weeks of pregnancy, and that the establishment of pregnancy during the fourth week of lactation is not detrimental to the growth of the suckled young when supplementary food is provided.
Yield of colostrum and immunoglobulin in cattle at the first milking after parturition
Authors: Kruse V. 
Published: September 2010

SUMMARYThe experimental animals consisted of 71 heifers or cows of the Black and White Danish breed (SDM), 61 heifers or cows of the Red Danish breed (RDM), and 8 heifers or cows of the Jersey breed. Highly significant differences between breeds were found in yield of colostrum at first milking after calving and in the concentration of immunoglobulin (Ig) in colostrum. The RDM animals had the highest colostrum yield but the lowest Ig %. The total yield of Ig was not significantly different between RDM and SDM. The individual variation in colostrum yield, Ig %, and Ig yield was very marked.Heifers had a lower colostrum yield and Ig yield than cows in second and later lactations. For SDM the Ig % was not dependent on the lactation number. In contrast the older RDM cows had a significantly higher Ig % in colostrum than the younger cows. No effect of season of the year was found on colostrum yield, Ig %, and Ig yield. An increase of the interval between calving and the first milking caused a very significant drop in colostrum Ig %. Loss of colostrum from the udder before milking increased the probability of getting colostrum with low Ig %. The repeatability in Ig % at successive calvings was found to be high.
Computer simulation of reciprocal recurrent selection with overdominant gene action
Authors: Arthur J. A. , Abplanalp Hans 
Published: September 2010

SUMMARYPrevious studies have shown that reciprocal recurrent selection (RRS) would be ineffective in the early cycles of selection if over-dominant loci were at equilibrium gene frequencies in both selected populations. It is shown in the present study that response to RRS may be reduced by this unstable equilibrium even when gene frequencies are as much as 30 % removed from the theoretical equilibrium frequency. Reducing one population to a bottleneck of two individuals for one generation or more before initiating RRS (RRSB) was very effective in overcoming the unstable equilibrium. RRS with recurrent inbreeding, then outcrossing in both populations each cycle of selection (RRSC) was not effective in overcoming the unstable equilibrium, but yielded greater response per cycle after selection response began. The effectiveness of RRSC was inversely proportional to the heritability of the trait. Use of these modifications to increase the effectiveness of RRS in poultry breeding is discussed.
The development of solid food intake in calves. 1. The effect of previous experience of solid food, and the physical form of the diet, on the development of food intake after weaning
Authors: Hodgson J. 
Published: September 2010

SUMMARY1. British Friesian male calves were offered reconstituted milk substitute four times a day in steadily increasing quantities, so that the amount offered exceeded appetite after 14 days. They were given one of three dried herbage diets (pellets P1 and P2, and untreated material H2 made from the same crop as P2) to appetite, either from the start of the experiment (Treatment A) or from the start of weaning (Treatment W) 21 days after arrival. The experiment was terminated six weeks after the calves were weaned.2. Grinding and pelleting (P2 v. H2) markedly reduced the in vivo digestibility of the diet, and the time of retention in the alimentary tract, increased the voluntary dry-matter intake by 50% and live-weight gain of the calves by 100%. The intakes of the two pelleted diets were similar.3. The intake of diet H2 after weaning was greater in calves which had experience of the diet before weaning than in those which did not, but the intake of the pelleted diets was not affected by previous experience of solid food. The time required to eat unit weight of dry matter was four times as long for diet H2 as for the pelleted diets, and there were similar differences between diets in ruminating time. It is suggested that the development of solid food intake is influenced by the ease with which the diet can be eaten.4. The initial increase in solid food intake after weaning was related to an increase in the times spent eating and ruminating, but later increases in food intake were achieved with no further increases in eating or ruminating time.
Investment appraisal for national breeding programmes
Authors: Hill W. G. 
Published: September 2010

SUMMARYThe discounted cash flow procedure of management accounting is used to evaluate national breeding programmes. Alternative methods of improvement of meat production from cattle born in the dairy herd are taken as examples. These schemes utilize selection for beef characters either in the dairy breed itself or within a beef breed, maintained in a small herd and used as a source of bulls for crossing by AI. In each case young bulls are selected for growth rate in a performance test, which precedes the progeny test for milk production in the dairy breed.Greater rates of genetic progress and monetary returns are predicted from improvement of the beef breed, but both schemes are expected to yield a return on investment of over 15%. The net returns from the programme in the beef breed are influenced less by changes in assumptions.Approximate, but simple, methods of computing the discounted returns are described.
The voluntary intake of roughages by pregnant and by lactating dairy cows
Authors: Marsh R. , Curran M. K. , Campling R. C. 
Published: September 2010

SUMMARY1. Effects of late pregnancy and early lactation on the voluntary intake of dried grass (Expt 1) and a poor quality seeds hay (Expt 2) by dairy cows are described. Each cow received a constant daily allocation of concentrates throughout late pregnancy. After calving half the cows received an 80% increase in concentrates, and the remainder continued to receive their pre-partum allowance.2. Mean daily intakes of dried grass were higher than those of poor quality seeds hay. Intake of dried grass in week 2 of lactation was significantly correlated with the live weight of the cows, but a non-significant correlation was observed when seeds hay was offered.3. During late pregnancy mean daily intakes of both roughages were approximately constant until the week immediately before par turition, when a significant decline occurred.4. After calving mean daily intakes of both roughages increased throughout the first six weeks of lactation by 20–30% of the intake at week 1 post partum.5. The 80% increase in daily concentrate allocation in early lactation caused a significant decline of 0·55 kg dried grass dry-matter intake per kg concentrate dry matter; the decline of 0·17 kg poor quality hay dry matter per kg concentrate dry matter was not significant.