bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of sire with feeding regime interaction in pigs
Authors: Cameron N. D. , Curran M. K. , Thompson R.
Published: September 2010

The interaction of sire with feeding regime (ad libitum and restricted) was assessed in the first stage of a selection experiment. There were 79 sires (59 Large White (Edinburgh) and 20 British Landrace (Wye)) with 1549 progeny (745 at Edinburgh and 804 at Wye) in the study. Progeny within each litter were allocated at random to each feeding regime. Pigs started test at 30 (± 3) kg and finished test at 85 (± 5) kg for ad libitum fed pigs or after 84 days on test for restricted fed pigs. All pigs were individually penned. At the end of test, food intake, weight off test and ultrasonic backfat depths were recorded. Variance components were estimated using restricted maximum likelihood and a weighted analysis took account of the different residual variances between feeding regimes, within each breed.

There were differences in some genetic parameters due to feeding regime within breeds. No evidence of a sire with feeding regime interaction for average daily gain or food conversion ratio was detected in Large White pigs (genetic correlations between ad libitum and restricted feeding were 1·21 (s.e. 0·17) and 0·89 (s.e. 0·19) respectively). Similar conclusions could not be made for the sample of British Landrace pigs due to the large standard errors of the genetic correlation estimates. For ultrasonic backfat depths, the negative estimates of sire variances under restricted feeding prevent calculation of the genetic correlations and conclusions to be made about the sire with feeding regime interaction.
A note on the food conversion and meat quality of crossbred Aberdeen Angus and Charolais heifers
Authors: Hankey Catherine , Kay M.
Published: September 2010

The food conversion and meat quality of 10 Aberdeen Angus and 10 Charolais crossbred heifers, about 18 to 20 months of age, was measured. The animals were finished using diet of hay and concentrates for up to 10 weeks prior to slaughter at either fat class or 4L using the Meat and Livestock Commission scheme. There were no significant breed differences in food conversion. Post slaughter, samples of muscle from the L. dorsi over the 11 to 12th rib from all heifers were used for sensory evaluation using a trained taste panel. The muscle from heifers in fat class 4L showed an increased flavour intensity compared with those in fat class 3 (P < 0·05). No other differences in sensory characteristics were found. The measurement of muscle fibre areas in the L. dorsi revealed no significant differences, suggesting a similarity in the texture of the meat from the breeds when slaughtered at the same age.
Effect of duration of wilting on the conservation of silage and on gains in body components by steers
Authors: Charmley E. , Thomas C.
Published: September 2010

Four silages were prepared from a sward of perennial ryegrass (Lolium perenne cv. Melle). Two were ensiled directly either without (UWN) or with formic acid at 31 1/t fresh material (UWA). The remaining herbage was left undisturbed in the swath for 43 h (WL) or was spread and harvested after 19 h (WS). The dry matter (DM) concentrations at harvest for the unwilted herbage were 229 (UWN) and 238 g DM per kg (UWA) and wilting increased DM concentration to a similar extent for both treatments (WS, 339 v. WL, 346 g DM per kg).

Forty British Friesian steers initially 3·5 months of age and 105 kg live weight were used for the trial. Eight steers were allocated to an initial slaughter group and the remainder were offered the four silages at a restricted level to give 940 kJ digestible energy per kg M0·75. These animals were slaughtered after 112 days to estimate the incremental increases in the components of the body.

Loss of DM in the field by respiration increased from 22·2 to 40·6 g/kg DM cut with increased length of wilting. In silo losses were greater with unwilted (UWN, 222, UWA 183 g/kg DM ensiled) than with wilted silage (WS, 133 WL, 122 g/kg DM ensiled). All silages were well preserved. Wilting was more effective than formic acid in reducing total fermentation acids but a lower proportion of these acids was in the form of lactic acid.

Live-weight gain was lower for the steers given the control (UWN) silage (398 g/day) than for those given silages UWA (463 g/day), WS (476 g/day) and WL (470 g/day). However, a lower proportion of the gain by steers given UWN was in the form of gut contents so that gains in fat, protein and energy were not significantly affected by treatment. In conclusion, when steers were given similar amounts of digestible energy and unwilted silage was well preserved, neither the use of formic acid nor wilting influenced gains in protein and energy. Further, the duration of wilting, in the absence of any differences in DM content, had no effect on animal performance.
Influence of ammonia treatment and supplementation on the intake, digestibility and weight gain of sheep and cattle on barley straw diets
Authors: Silva Ayona T. , Greenhalgh J. F. D. , Ørskov E. R.
Published: September 2010

Three experiments of 2 × 2 × 2 factorial design were made with sheep or cattle given a basal diet of barley straw. Fish meal (FM) and unmolassed sugar-beet pulp (SBP) were given either separately or in combination as supplements to untreated (US) or ammonia-treated barley straw (AS) to form eight diets. The diets were given for 8 weeks in experiment 1 (24 sheep), 10 weeks in experiment 2 (24 steers) and 20 weeks in experiment 3 (32 steers and bulls). Urea was added to the shredded straw US and AS, to give a final concentration of 17 g nitrogen per kg dry matter (DM). n I experiments 1 and 3, both FM and SBP, given alone or in combination, significantly increased the DM and organic matter digestibility of urea-supplemented US, but not of AS. Ammonia treatment of straw given alone increased DM intake from 414 to 729 g/day in sheep and from 4·75 to 6·09 kg/day in cattle. All animals given US as the sole food lost body weight, but cattle gained weight when US was combined with either 50 g/kg FM or 15 g/kg SBP. It was necessary to combine the two supplements to achieve a significant gain in body weight of sheep. Although the diets based on AS promoted growth in all the animals, the body-weight gains achieved with US combined with 50 g/kg FM or 15 g/kg SBP were greater than those when AS was given as the sole food.
Rebreeding activity in milking Awassi ewes under semi-arid conditions
Authors: Kassem R. , Owen J. B. , Fadel I.
Published: September 2010

Post-partum interval to oestrus and conception was studied in relation to previous and current lactation (milk yield and lactation length), age of ewe and treatment with intravaginal sponges in a total of 186 Awassi ewes lambing in December/January. In the first trial, 62% of ewes, tested for oestrus twice a day with vasectomized rams until the end of May, showed oestrus between 1 and 170 days after lambing with a mean interval of 83 (s.d. 31·9) days. Neither current nor previous lactation had important effects on the rebreeding interval (P > 0·05). In another trial where ewes were exposed continuously to fertile rams until the end of March, 50% showed oestrus with a mean interval of 56 (s.d. 23·7) days (range 33 to 113 days). Of those showing oestrus, 86% conceived with a mean post-partum interval of 70 (s.d. 33·0) days (range 33 to 133 days). Lactation yield had no significant effect on the lambing-to-oestrus interval (P > 0·05) but ewes with longer lactations showed longer lambing-to-conception intervals (P > 0·01). Treatment with progesterone-impregnated vaginal sponges at 1, 2 and 3 months post partum showed an increase in the percentage of ewes showing oestrus from 35% to 75% and in those conceiving from 25% to 70% as the timing of treatment increased from 1 to 3 months post partum. It is concluded that lambing three times in 2 years is biologically feasible and that hormone treatment can facilitate its operation in practice.
The effect of dietary inclusion of yeast culture on digestion in the sheep
Authors: Chademana I. , Offer N. W.
Published: September 2010

Six mature sheep, each fitted with a rumen cannula, were assigned to six diets in a 6 × 6 Latin-square design experiment to examine the effects of a yeast culture on ruminal metabolism, rumen liquid outflow rate, fibre digestion in the rumen and overall nutrient digestibility. The yeast culture (YC) was a commercial product composed of a yeast (Saccharomyces cerevisae) and the media on which it grew and dried so as to maintain its fermentative capacity. The six dietary treatments were three diets differing in hay dry matter (DM): concentrate DM ratio (90: 10, 65: 35 and 40: 60 designated low, medium and high concentrate respectively) each given either without or with a supplement of 4 g/day of YC. Treatment periods were of 3 weeks duration. There were significant effects of dietary forage: concentrate ratio on rumen function (P< 0·05). Rumen pH, rumen liquid outflow rate, rumen ammonia concentration, total volatile fatty acids concentration, and molar proportions of acetate, propionate and butyrate were not significantly affected by the inclusion of YC (P< 0·05). Supplemental YC did not affect the overall nutrient digestibility of organic matter, neutral-detergent fibre or gross energy measuredin vivo. However, at every forage:concentrate ratio, YC increased the disappearance of hay organic matter from nylon bags incubated in the rumen for 24 h (P< 0·05). The values with and without YC were 0·482 and 0·432 for the low, 0·423 and 0·366 for the medium, and 0·360 and 0·321 for the high concentrate diets respectively. However, YC had no effect on hay disappearance when bags were incubated for 48 h. YC appeared to increase the initial rate of forage digestion in the rumen without altering overall food digestibility or the patern of production of fermentation end products.
Effect of protein and energy intake on digestion and nitrogen metabolism in wethers and on ovulation in ewes
Authors: Waghorn G. C. , Smith J. F. , Ulyatt M. J.
Published: September 2010

Two experiments were conducted to investigate the basis for an increase in ovulation rate in ewes given improved nutrition prior to mating.

Sixteen wether sheep were used in the first experiment in order to screen physiological and nutritional variables likely to be affected by protein and energy intake. They were given low protein (LP) and high protein (HP) diets (19·1 and 35·2 g nitrogen per kg dry matter (DM)) each at four levels of energy intake (range 7·67 to 27·06 MJ gross energy per day). Effects of treatment on digestibility and partition of digestion between the rumen and intestines were small but increased nitrogen intake increased both nitrogen retention and the concentration of some essential amino acids (EAA) in plasma. The dietary treatments imposed on the wethers had been given to 800 ewes previously in a separate trial designed to predict ovulatory response to dietary and energy intakes. When the variables measured in the wether sheep were compared with predicted ovulation for ewes given the same treatments, the strongest relationship was with plasma concentrations of branched-chain amino acids (BCAA; r = 0·95; P < 0·001). Correlations with other EAA were weaker (r = 0·61; P < 001) and were not significantly related to concentrations of non-essential amino acids (NEAA) in plasma (r = −0·21).

Eighty ewes in experiment 2 were given an LP diet, blood samples were taken and ovulation rate determined by laparoscopy. One group of 20 ewes was maintained on the diet and another group of 20 was given an HP diet starting on day 7 of the oestrous cycle. Blood samples were taken 5 days later and numbers of ova determined during the next cycle. There were no changes in the number of ova present in ewes maintained on the LP diet, but a change to the HP diet increased ovulation rate from 1·47 to 1·89 eggs per ewe. Ewes which had single or multiple ova when given the LP diet (pre-treatment) had similar concentrations of amino acids in their blood, but those given the HP diet increased blood concentrations of BCAA by proportionately 0·58 and other EAA by 0·29 whilst NEAA were unaffected. Ewes which increased their ovulation rate when given the HP diet had a greater increase in blood BCAA concentration than those which did not increase their ovulation rate. Both the concentration in blood and the magnitude of increase in BCAA concentration appear to affect the number of eggs released. This concept is supported by evidence that BCAA are able to exert regulatory effects on mammalian protein metabolism under some circumstances.
Grassland performance of Hereford cattle selected for rate and efficiency of lean gain on a concentrate diet
Authors: Bishop S. C.
Published: September 2010

The performance of 273 Hereford calves from lines previously selected for lean growth rate (LGR) or lean food conversion efficiency (LFCR), on a concentrate diet, was evaluated on a grassland diet over a period of 3 years. Both bull and heifer calves were tested, and each year the performance test ran from the 1st week of May (average age of 233 days) until the 1st week of October. Carcass lean content was predicted from body weight and ultrasonic backfat depth, and lean gain was calculated from the product of live-weight gain and predicted carcass lean content. The LGR line was superior to the control (C) line for live-weight gain on test, lean gain on test and lean gain from birth until the end of test. The LFCR line performed similarly to the C line for live-weight gain on test and lean gain on test, but was inferior for total lean gain. For lean gain on test, the proportional differences between the lines were similar to those predicted from parental breeding values for LGR, but they were smaller for total lean gain. The lines did not differ significantly for either fat depth or predicted carcass lean content.

Heritabilities were high for all growth traits, e.g. 0·52 (s.e. 0·17), 0·54 (s.e. 0·17) and 0·59 (s.e. 0·17) for live-weight gain on test, lean gain on test and total lean gain, but lower for fat depth and carcass lean content, 0·25 (s.e. 0·17) and 0·14 (s.e. 0·16), respectively. Genetic correlations with LGR, measured on a concentrate diet, were 0·57 for lean gain on test and 0·56 for total lean gain. If only males were considered, these correlations rose to 0·80 and 0·70, respectively. Coheritabilities between the two environments for lean growth were close to 0·3. It is concluded that although there is some evidence for genotype × environment and genotype × sex interactions, selection for lean growth on a concentrate regimen will still be effective in improving grassland performance.
Urinary excretions of purine derivatives and nitrogen in sheep given straw supplemented with different sources of carbohydrates
Authors: Balcells J. , Fondevila M. , Guada J. A. , Castrillo C. , Surra J. C. E.
Published: September 2010

Estimations of purine derivatives excretion and urinary-nitrogen loss were used to test the response of rumen fermentation to supplementation of straw with different sources of carbohydrate. Two groups of Rasa Aragonesa ewes (44 (s.e. 0·75) kg live weight were givenad libitumbasal diets of either ammonia-treated (ATS) or urea-supplemented (USS) barley straw, with 12 animals per basal diet group. Three supplements, barley grain, sugar-beet pulp or grass hay, respectively, were given to each basal diet group, giving a total of six dietary treatments with four animals per treatment group. Four levels of supplementation were studied (150, 300, 450 and 600 g air dry matter per day), one in each of four experimental periods. Each 45-day experimental period comprised 38 days of adjustment followed by a 7-day measurement period. Digestible organic matter (DOM) intake was higher in animals receiving ATS than in animals receiving USS (504v.474 (s.e. 21·1) g/day,P< 0·005) and higher in animals receiving barley grain and sugar-beet pulp than in those receiving grass hay (512 and 496v.370 (s.e. 25·9) g/day,P< 0·005). DOM intake also increased with the level of supplementation and this increase was greater with barley grain (504 to 634 and 314 to 554 g/day for ATS and USS) and sugar-beet pulp (440 to 582 and 315 to 522 g/day) than with grass hay (430 to 407 and 267 to 370 for ATS and USS). Urinary excretions of hypoxanthine, xanthine and uric acid were not affected by the experimental treatment whereas allantoin excretion (y, mmol) increased in response to DOM intake (x, kg) (y = 13·72 × − 0·26; r = 0·79;P< 0·001; no. = 96). The response in allantoin excretion was mainly explained by the increase in DOM intake. However when data were expressed per unit of DOM intake significant differences were still evident. Allantoin/DOM intake (mmol·kg) ratio and calculated microbial nitrogen (g·kg DOM intake) supply were lower with USS diets and sugar-beet pulp supplemented diets (P< 0·05) and increased significantly with level of supplementation (P< 0·001).
Genetic evaluation of birth and weaning weight of Gudali and two-breed synthetic Wakwa beef cattle populations under selection in Cameroon: genetic and phenotypic trends
Authors: Tawah C. L. , Rege J. E. O. , Mbah D. A. , Oumate H.
Published: September 2010

Breeding programmes for Wakwa and Ngaundere Gudali cattle breeds were initiated in Wakwa (Cameroon) in 1952 and 1965, respectively, to improve growth performance of the indigenous breeds. Animals were selected on 240-day weaning weight (WWT). Data analysed covered the period 1971 through 1985 and consisted of 2211 calf birth weight (BWT) and 1409 WWT records on Gudali and 1196 BWT and 763 WWT records on Wakwa. Selection responses in BWT and WWT were estimated as regressions of average sire estimated transmitting abilities (ETAs) and average dam estimated breeding values (EBVs) on year of calving. ETAs and EBVs were predicted using best linear unbiased prediction procedures. Estimated annual changes in sire ETAs for WWT were 0·67 (s.e. 0·17) and 1·69 (s.e. 1·13) kg/year for Gudali and Wakwa, respectively. Corresponding trends in dam EBVs were –0·03 (s.e. 0·03) and –0·24 (s.e. 0·19) kg/year. Estimated correlated trends in BWT among Gudali and Wakwa sires were 0·09 (s.e. 0·05) and –0·14 (s.e. 0·04) kg/year, respectively. Corresponding correlated trends in BWT associated with dam selection were essentially zero, being –0·001 (s.e. 0·001) and –0·01 (s.e. 0·01) kg/year. Environmental trends were negative for all traits except Gudali WWT. Phenotypic trends were all positive, except that of Wakwa BWT. Overall, selection on WWT yielded moderate selection reponse despite substantial infrastructural constraints in the breeding programme. Trends in sire ETAs and dam EBVs for WWT jointly accounted for estimated genetic gains of 8·60 kg in Gudali and 20·4 kg in Wakwa over the study period. Overall correlated response in BWT during the study period was significant (P < 0·001) and negative for Wakwa. It was positive but not significant for Gudali.
Growth and body composition of Omani local sheep 2. Growth and distribution of musculature and skeleton
Authors: Mahgoub O. , Lodge G. A.
Published: September 2010

Distribution of tissue weight in the musculature and skeleton was studied in ram, wether and ewe Omani sheep raised under an intensive management system and slaughtered over the range 18 to 38 kg live weight. Ram lambs had higher muscle weight in the forequarters than wether and ewe lambs whereas the latter ‘sexes’ had heavier hindquarters and slightly more muscle in the muscle groups of proximal hind- and forelimbs and those surrounding the spinal column. Some of the neck region muscles, e.g. m. splenius and m. longissimus capitis et atlantis, were more developed in ram than in wether and ewe lambs. The proportions in the side muscle weight of some muscles (mainly in the hindquarter) decreased with increased slaughter weight whereas others (mainly in forequarter) increased, with the majority of the muscles showing no significant slaughter weight effects. The magnitude of change in proportions of individual muscles with increased slaughter weight was small and unlikely to have a commercial impact on meat production from Omani sheep.

As a proportion of total carcass bone, the axial skeleton and the hindlimb decreased with increased slaughter weight whereas the forelimb did not show a significant change. Ram lambs had heavier individual bones than wether and ewe lambs and higher proportions of the axial skeleton and lower proportions of the hindlimb than wethers at 28 kg live weight. There were few differences between the various ‘sexes’ in length, width or circumference of bones. Except for the 12th rib, individual bones, in all sexes, grew at a rate lower than empty body weight.

It is suggested that future improvement of Omani sheep should take into consideration the high proportion of bone in the carcass of these animals as well as the relatively higher proportion of bone in the limbs than in the axial skeleton.
Growth-related hormones in plasma of bulls, steers and heifers given food with two different energy levels
Authors: Röpke R. , Schams D. , Schwarz F. J. , Kirchgessner M.
Published: September 2010

Concentrations of growth hormone (GH), insulin-like growth factor (IGF-1), insulin and glucagon were determined in the plasma of growing bulls, steers and heifers (no. = 138 in total, German Simmental breed). The animals were offered either a high level or a low level of energy resulting in relatively high and low average daily gain. Trials were subdivided into two experimental series and started at approximately 3 months of age at an average live weight of 110 kg. The animals were slaughtered at different body weights from 200 to 510 kg (heifers) or 660 kg (bulls, steers). Blood samples (needle puncture) were collected at biweekly intervals. Frequent samples time-course analysis of GH were taken by catheter from nine animals in total. Concentrations of GH declined during growth in steers and heifers as well as in bulls in blood samples collected by means of a catheter. IGF-1 and insulin concentrations increased from the start of the trial onwards up to different ages among the groups. Concentrations of glucagon constantly decreased from the start of the trial until slaughter. Significant differences (P < 0·05) in concentrations ofGH, IGF-1 and insulin could be observed between sexes and levels of nutrition, with the highest GH and IGF-1 levels in bulls followed by steers and heifers. In contrast insulin values were highest in heifers followed by steers and bulls. A high level of nutrition increased concentrations of IGF-1 and insulin in all sexes.
The effect of pre- and post-partum energy and protein supply on the performance of single- and twin-suckling beef cows and their calves
Authors: Sinclair K. D. , Broadbent P. J. , Hutchinson J. S. M.
Published: September 2010

Changes in live weight, body condition, milk production and composition were monitored for single- and twinsuckling cows in two experiments. In experiment 1, all cows were managed for 3 months before calving to achieve condition scores at calving 2·1 (low) and 3·1 (moderate). Subsequently, these animals were placed on a fixed level of energy intake (80 MJ metabolizable energy (ME) per day) for 16 weeks. Post-partum diets contained differing amounts of digestible undegradable protein (DUP), but similar amounts of effective rumen degradable protein (ERDP). In experiment 2, single- and twin-suckling cows were fed to achieve a condition score at calving of around 2·75. These animals were subsequently placed on two levels of energy intake (80 MJ and 130 MJ ME per day) during the first 16 weeks of lactation. The diets providing these energy intakes also contained differing amounts of DUP. Neither the level of DUP in the diet nor the level of feeding significantly altered the digestibility of the dry matter or organic matter in the dry matter of the experimental diets.

Body condition at calving had little effect on daily milk yield (9·5 kg) and composition (33·5 g/kg fat; 30-0 g/kg protein) in experiment 1. Cows with higher body condition scores at calving lost 13·5 kg more live weight and 0·26 units more body condition (P < 0·05) during the 1st month post partum but remained in better condition throughout the trial period than cows with lower body condition scores. Cows on 130 MJ ME per day produced higher (P < 0·001) daily yields of milk, milk fat and protein (+2·0 kg; +151 g; +85 g) and lost 57 kg less live weight and 0·52 units less body condition (P < 0·001) than cows on 80 MJ ME per day. Elevated dietary levels of DUP promoted (P < 0·05) daily milk yields (by 1·25 kg) and reduced live-weight and body condition-score loss during the 1st month post partum in both experiments. Twin-suckling cows produced the highest average daily yields of milk throughout the 16-week trial period in both experiments but yields were not significantly higher after early lactation in experiment 1. Cow body condition score at calving and the level of DUP in the post-partum diet of cows had no effect on the post-partum performance of calves. Twin calves had slower growth rates (P < 0·001) than single calves (0·65 and 1·07 kg/day respectively) in experiment 1. However, twin calves sucking cows on 130 MJ ME per day in experiment 2 grew similarly to single sucking calves from week 8 of lactation (0·8 kg/day).
The effect of condition at service and plane of nutrition in early pregnancy in the sow 1. Uterine and extra-uterine changes
Authors: Pike I. H. , Boaz T. G.
Published: September 2010

Twelve sows (F) were fed 7·3 kg/day and twelve (T) 3·7 kg/day of a 16% crude protein (CP) diet for the last 5 weeks of an 8-week lactation, so that at the subsequent service F sows were heavier (16%) and in better condition.

From service to slaughter 70 days later, sows received either 3·7 kg/day (H) or 1·8 kg/day (L) of a 15% CP diet, giving four treatment combinations; FH, FL, TH and TL.

In pregnancy H sows gained more weight than L sows and, on the low plane, F sows gained more weight than T sows. Ovulation rate as measured by corpora lutea count at slaughter was higher for TH than TL sows and for FL sows than FH sows. A combination of low ovulation rate and high mortality rate gave fewer foetuses (10·0) in the TL sows than in sows on the other treatments (13·5). Similarly mean foetal weight and thus foetal litter weight was least in TL sows. Foetal membranes, uterine fluids and uterine wall were lighter at slaughter in T sows than F sows and lighter in L sows than H sows, those of TL sows being appreciably the lightest.

The results indicate that when the sow is in poor condition at service, body reserves being depleted, the uterus and its contents become more vulnerable to adverse pregnancy nutrition.
The nutrition of artificially reared lambs 2. The effect of feed restriction at three stages of growth on growth and carcass composition
Authors: Morgan J. A. , Owen J. B.
Published: September 2010

Lambs weaned from the ewe at 2 days of age were fed ad libitum or restricted in each of three periods of growth to a slaughter weight of 35 kg according to a factorial design. Restriction in the milk-feeding period was achieved by reducing the milk allowance (6·4 kg v. 13·6 kg of milk replacer) and after weaning, by restricting the daily allowance of feed.

Restriction of the milk allowance reduced early growth but the effect was partly offset by the higher concentrate consumption of restricted lambs. There was also a tendency for lambs restricted in the milk period to eat more and grow faster when subsequently fed ad libitum. Performance after 15 kg on a diet containing no protein of animal origin was poor and the level of restriction was severe. Overall growth and efficiency from 15 to 35 kg were considerably reduced by any degree of restriction. However, there was no evidence that restriction in the middle period of growth had any effect on the performance of lambs fed ad libitum in the final period. Although carcass weight was not affected by treatment at any stage, restriction in the milk-feeding period and feeding ad libitum from 15 to 25 kg resulted in a greater weight of head, liver, heart and lungs (weighed together). Chemical analysis of the whole minced carcass showed that restriction of milk intake had a significant effect in reducing the carcass dry-matter content. There was also a trend towards a higher energy and fat content of the dry matter. Restriction in the final period increased the protein content of the carcass.
Rearing of dairy cattle 3. A note on the use of whole milk for calves fed once daily
Authors: Leaver J. D. , Yarrow N. H.
Published: September 2010

Whole milk was given once daily to three groups each of 18 Friesian heifer calves and concentrates and hay were also available. Calves in one group received 2·4 kg milk/day and in a second 3·0 kg milk/day and in both of these groups individual calves were weaned when their daily intake of concentrates reached 400 g. In the third group the calves received 3·0 kg milk/day and were weaned after 28 days. Concentrate and hay intakes were not significantly affected by the treatments. Mean growth rate over 56 days increased with increasing quantity of whole milk offered but the differences between treatments were not significant. The performance of calves given whole milk was compared with the performance achieved in previous experiments where milk substitute was given. It was estimated that 1 kg whole milk gave the same live-weight gain as 170 g milk-substitute powder. From this estimate price/cost relationships were determined to indicate when whole milk or milk substitute should be fed to calves.
A note on a comparison of two systems for rearing pigs weaned at 2 days of age, involving either a liquid or a pelleted diet
Authors: Braude R. , Newport M. J.
Published: September 2010

In two experiments pigs were weaned at 2 days of age on to a liquid milk substitute, and from 7 days were either kept to 28 days in individual cages and given the liquid diet to a scale based on live weight, or kept in groups and allowed continuous access to the same diet in the form of pellets. The dry-matter intake from the pelleted diet was considerably less than that from the liquid diet, and the live weight of the pigs given the liquid diet was considerably greater at 28 days. The type of diet did not affect the feed: gain ratio. A liquid diet seems essential to realize the maximum growth potential of pigs weaned at 2 days of age. All pigs received a pelleted diet from 29 days and their overall performance from 2 to 56 days was similar regardless of initial treatment.

In a further experiment, the performance of pigs given the liquid diet was better when individually caged rather than when kept in groups.
The effect of body size and body condition on the ovulation rate of ewes
Authors: Ducker M. J. , Boyd J. S.
Published: September 2010

Body size was estimated for 255 Greyface ewes using five linear body dimensions. On the basis of this calculated measure combined with a subjective measure of body size 50 small and 50 large ewes were selected for use in the experiment. Precise ovulation data were obtained by endoscopy and this technique allowed the ewes to be mated subsequently.

Body size did not affect the mean ovulation rate of the ewes although, at the same level of body condition, the large ewes were 25% heavier than the small ewes. The ovulation rates and the numbers of lambs born were influenced by changes in live weight and body condition. For these reasons live weight per se was not a good indicator of ovulation rate as ewe live weight was a combination of both body size and body condition. At the same live weight small ewes in improving body condition had a significantly higher ovulation rate than large ewes in reducing body condition.

The onset of the breeding season of the ewes was not affected by their body size. The mean date of onset of oestrous activity for both large and small ewes was 17 October 1972 at a latitude 55° 52′ N.
Superovulation and non-surgical embryo recovery in the lactating dairy cow
Authors: Brand A. , Trounson A. O. , Aarts M. H. , Drost M. , Zaayer D.
Published: September 2010

A simple non-surgical technique was used to recover embryos from lactating dairy cattle, given 3000 IU PMSG to induce superovulation and the results obtained were compared with the ovulation rate and recovery of embryos from slaughtered cows.

In the slaughtered cows, which were treated late in lactation, mean ovulation rate was only 8·3 ± 1·24 or 9·8 ± 1·26 excluding cows that failed to ovulate. A mean of 6·1 ± 0·63 eggs was recovered but only 4·2 ± 0·63 were normally developed embryos. In the cows treated in mid-lactation for non-surgical embryo recovery, 25/92 had fewer than three ovulations. A mean of 3·5 ± 0·45 eggs was obtained non-surgically from 58 cows that were flushed, and 3·1 ± 0·44 were normal embryos. The estimated recovery rate of normal embryos non-surgically was 38 % of those ovulated compared with 43 % from slaughtered animals.

It appears that the lactating dairy cow has a rather low ovulatory response to PMSG but by the repeated use of the non-surgical embryo recovery method described, sufficient numbers of embryos may be obtained on a yearly basis to justify the use of the procedure for the improvement and dissemination of dairy breeds.
Genetic and non-genetic factors affecting pre-weaning survivability in kids
Authors: Singh D. K. , Mishra H. R. , Singh C. S. P.
Published: September 2010

The present study was carried out on 1243 kids (379 Black Bengal; 568 Jamunapari × Black Bengal and 296 Beetal × Black Bengal) born between 1981 and 1986. Data were analysed to study the influence of genetic group, sex, season of birth, type of birth, birth weight, dam's weight at kidding, filial generation and parity of dam (as covariate) on survivability of kids during the pre-weaning period (0 to 90 days of age). The overall survival rates during 0 to 15, 16 to 30, 31 to 60, 61 to 90 and 0 to 90 days of age were 81·68 (s.e. 2·89), 95·55 (s.e. 2·00), 90·77 (s.e. 2·33), 93·31 (s.e. 2·59) and 69·94 (s.e. 3·65) % respectively. Variation in survival rates from 0 to 15 days of age was significant due to genetic group (P < 0·01), birth weight (P < 0·01), dam's weight at kidding and parity of dams as a covariate (P < 0·05). Season of birth (P < 0·05), weight of kids (P < 0·01) and dam's weight at kidding (P < 0·01) had significant effects on survival rate during 0 to 90 days of age. Sex and type of birth had no significant effect on survival rates. The interaction effects of genetic groups with season of birth and sex on pre-weaning survival rates were not significant in all ages except the effect between genetic group and sex during 31 to 60 days of age. An improvement in survival rates during the period of study was noticed with the increase in filial generation number from Fj to F3, although the difference was not significant except from 61 to 90 days of age (P < 0·05). Birth weight of kids had a positive linear relationship with survivability during the pre-weaning period. Summer-born kids had a significantly lower survival rate than those born in the winter and monsoon periods from 16 to 30, 61 to 90 and from 0 to 90 days of age. A negative linear relationship was observed between dam's weight at kidding and survival rates of kids from 0 to 90 days of age except the 25 to 30 kg dams deviate. Heritability estimates of survival rates during pre-weaning periods were not significantly different from zero, indicating that improvement by simple selection is probably limited.
Effect of boar exposure on expression of genetic potential for age of puberty in gilts
Authors: Safranski T. J. , Lamberson W. R. , Bates R. O.
Published: September 2010

Genotype × environment interaction for age at puberty was evaluated using gilts from the Nebraska Gene Pool population derived from lines selected randomly (RS; no. = 48) or for seven generations for decreased age at puberty (AP; no. = 73). Age at puberty was evaluated in two environments: boar exposure for 15 min daily (BE) or no boar exposure (NBE). Pigs were randomly assigned to treatment and mixed into groups of 20 in pasture lots. Oestrous detection was initiated when the oldest gilt in a pen was 125 days of age. Blood samples were taken weekly and assayed for progesterone. Gilts were considered to have expressed oestrus if they exhibited lordosis or had consecutive weekly blood samples with progesterone values above 6·4 × 109 mol/1 (2 μ, g/l). Gilts were removed from the pen upon confirmation of puberty or at 250 days of age. Two gilts failed to reach puberty by 250 days so this value was assigned as their age at puberty. Least-squares analyses of variance were used to analyse the data. A model including line, sire within line, farrowing group, treatment and line × treatment interaction was fitted to the dependent variables age at puberty and percentage cycling by 185 days. Line and treatment each affected age at puberty (P < 0·05) but did not interact. Least-square mean ages at puberty were 154 (s.e. 4·5), 164 (s.e. 4·7), 164 (s.e. 6·1) and 179 (s.e. 5·9) days for AP-BE, AP-NBE, RS-BE and RS-NBE, respectively. Treatment affected percentage of gilts cycling by 185 days (P < 0·05). Least-square percentages were 91 (s.e. 6·9), 76 (s.e. 71), 84 (s.e. 9·2) and 65 (s.e. 8·9) % for AP-BE, AP-NBE, RS-BE and RS-NBE, respectively. These results indicate that expression of response to selection for decreased age at puberty in the gilt is not dependent on stimuli from the boar.
Behaviour patterns of intensively fed male calves as affected by allowance and type of space, diethylstilboestrol implantation, and ration
Authors: Ilan D. , Levy D. , Holzer Z.
Published: September 2010

The effects of two levels of roughage (18 or 40%), of DES implantation (36 mg, twice), and of the addition of adjoining dirt yards to pens with concrete slatted floors, on the behaviour of intact male calves, were examined in a 2 x 2 x 2 factorial experiment. Observations were carried out on four days, every 15 min for 24 hr. Activities recorded were: standing, lying, eating, drinking, ruminating, jumping and idling.

Animals on the high roughage diet spent 26% more time eating, 5% more time drinking, and 19% more time ruminating, than those on the low roughage diet.

Most of the rumination was performed while the animals were lying down. Animals allowed yards adjoining their pens spent 20% less time ruminating and 13% more time jumping than animals confined to pens alone. Those allowed the yard preferred to stand there and to lie down in the pen. The yards were used more on a cool day than on a hot day.
A note on the effect of polyethylene particles on rumen metabolism of strees
Authors: Fordyce J. , Kay M.
Published: September 2010

Experiments were carried out to determine the effects of giving 1·36 kg of ‘RuffTabs’, polythene particles of dimension 1·27 × 0·63 × 0·95 cm3 (RT) to castrated male cattle (steers) given an all-concentrate diet, on the outflow of fluid from the rumen, on rumination and on the molar proportions of volatile fatty acids produced in the rumen.

RT reduced the flow of fluid from the rumen of steers, given a restricted amount of an all-concentrate diet, from 4·65 to 2·75% rumen volume/hr. RT had no effect on the total time spent daily in ruminating and eating. The molar proportions of volatile fatty acids were unaffected by RT in steers which were given the diet ad libitum but when RT was given to steers offered a restricted allowance of feed there was a highly significant (P < 0·001) reduction in acetic and an increase in butyric, valeric and caproic acids.

The feed intake of the steers was unaffected by RT.
A note on environmental factors affecting beef cattle performance tests
Authors: Collins-Lusweti E. , Curran M. K.
Published: September 2010

Field data from four breeds (Charolais, Hereford, South Devon and Welsh Black) comprising a total of 145, 68, 262 and 197 records respectively and obtained from 30, 24, 38 and 25 herds were used. Station data from two breeds (Charolais and Hereford) comprising 268 and 687 records respectively, from cattle originating from 27 and 44 herds respectively were also used. The data were analysed to identify environmental factors which significantly affected bull performance traits. In performance traits, herd of origin, in field and station data, accounted on average for 0·50 and 0·18 respectively of the total variance. Year, season and dam's age accounted for 0·02, 0·03 and 0·02 respectively of the total variance, the last being higher in pre-weaning than in post-weaning traits.
A survey of reproductive performance in dairy herds. Characteristics of the patterns of progesterone concentrations in milk
Authors: Bloomfield Glenys A. , Morant S. V. , Ducker M. J.
Published: September 2010

Progesterone concentrations were measured by radioimmunoassay in fat-free milk samples obtained three times weekly from calving until day 60 of pregnancy from over 700 cows in commercial dairy herds. Profiles of progesterone concentration during the ovulatory cycle and early pregnancy were also examined. In 94% of the animals cycling had commenced by 60 days post partum and a further 3% had shown some ovarian activity. In 34% of cows, the resumption of regular ovulatory activity was preceded by short periods of progesterone secretion which did not meet the criteria for a 'normal cycle’. Peaks of progesterone cross-reactivity (>0·75 ng/1) were detected at the time of ovulation in proportionately 0·06 of all cycles. There was no relationship between the detection of oestrus and the length of the following progesterone cycle or the concentrations during that cycle. However, there was a tendency for the first progesterone cycle post partum to be more variable in length than later cycles (0·56 within the range 18 to 24 days compared with 0·70 of later cycles; P < 0·001). Extension of the length of the luteal phase occurred in 58 second and later cycles (proportionately 0·141) following inseminations which did not result in calving. However, since the comparable figure for 1053 cycles where no insemination was given was 0·048, the overall figure for embryo mortality later than 24 days after insemination was estimated as 9·3%. Concentrations of progesterone in pregnant animals, compared to non-pregnant animals, and the distributions of luteal lengths between 8 and 21 days long following inseminations not resulting in calving could both be explained by early maternal recognition of pregnancy.
Interactions between supplementary nitrogen source and ration energy density on performance and nitrogen utilization in growing and fattening male cattle
Authors: Holzer Z. , Levy D. , Samuel V. , Bruckenthal I.
Published: September 2010

Four diets containing 9·6 MJ metabolizable energy (ME) per kg dry matter (DM) (LMEC), and four diets containing 11·3 MJ/kg DM (HMEC) were formulated. One diet of each ME concentration contained 90 g crude protein (CP) per kg DM and served as a negative control (NC). In the three other diets of each ME concentration, the level of CP was raised to 140 g/kg DM by inclusion of poultry litter (PL), non-protein nitrogen (NPN) or fish meal (FM). These diets were examined in a digestion and N balance trial and in a feeding trial.

For the NC, PL, NPN and FM subtreatments of the LMEC diets, DM intakes were 107·1, 112·4, 100·6 and 130·2 g/kg M075 respectively; digestibility coefficients of organic matter (OM) were 0·64, 0·70, 0·67 and 0·71 respectively; and N retention 0·40, 0·76, 0·53 and 1·21 g/kg M075 respectively. For the respective subtreatments of the HMEC diets, the values were: 100·4, 119·4, 109·3, 107·5 for DM intake; 0·64, 0·73, 0·73, 0·73 for digestibility coefficients of OM and 0·40, 0·87, 1·06 and 1·03 g/kg M075 for N retention.

Daily gain on the respective diets in the first 130 days of the feeding trial was 0·85, 0·90, 0·91, 1·04 kg for the LMEC and 1·09, 1·21, 119, 1·24 kg for the HMEC diets, and from the 131st day to slaughter was 0·98, 1·02, 100, 1·08 kg for the LMEC and 1·03, 1·02, 1·07, 1·05 kg for the HMEC diets respectively. Daily carcass gain was 0·49, 0·51, 0·51, 0·53 kg for the LMEC and 0·55, 0·59, 0·59, 0·60 kg for the HMEC diets, respectively.

The relationship between ME concentration in the diet and source of CP is discussed.
The effect of plane of nutrition and type of diet offered to yearling Friesian steers during a winter store period on subsequent performance
Authors: Steen R. W. J.
Published: September 2010

Three randomized block experiments, involving a total of 80 castrated male cattle, were carried out to examine the effects of plane of nutrition and type of diet offered during a winter store period from about 10 to 15 months of age on the subsequent performance of late-maturing, Friesian steers slaughtered at 22 to 23 months of age. A control diet of medium-quality grass silage (mean digestible organic matter in the dry matter (DOMD) 0·617) offered ad libitum and supplemented with 0·3 kg concentrates (17·1 to 25·6 g nitrogen per kg dry matter) per head daily, which was designed to sustain a live-weight gain of 0·4 kg/day, was compared with three diets which were designed to sustain a live-weight gain of 0·7 kg/day. These were medium-quality silage supplemented with 1·6 kg concentrates, medium-quality silage supplemented with 0·6 kg concentrates and 0·25 kg fish meal and high-quality silage (mean DOMD 0·704) supplemented with 0·3 kg concentrates. The animals were at pasture for 5 months after the treatment period and were then given silage and concentrates for 3 months until slaughter. The low and high planes of nutrition sustained mean daily live-weight gains of 0·43 and 0·73 kg respectively, giving a difference in live weight at the end of the treatment period of 45 kg. Compensatory growth at pasture reduced this difference to 30 kg. This resulted in a difference of 17 kg carcass weight between the two planes of nutrition. The type of diet offered at the high plane of nutrition did not affect subsequent performance. It is concluded that, when the live-weight gain of late-maturing, Friesian, yearling cattle was reduced below about 0·7 kg/day, there was relatively little compensatory growth during the subsequent period at pasture and consequently the optimum live-weight gain during the winter for this type of animal may be higher than that previously recommended.
The effect of level of concentrate supplementation in winter and grazing allowance on the milk production and financial performance of spring-calving cows
Authors: Reeve A. , Thompson W. , Hodson R. G. , Baker R. D. , Carswell A. J. P.
Published: September 2010

An experiment with a 2 × 2 factorial design was used to assess the effects of offering either 6 (L6) or 12 (H12) kg concentrates daily from day 13 of lactation until turnout to grazing with grass silage (600 to 620 g digestible organic matter per kg dry matter (DM)) ad libitum and either ad libitum (G) or restricted (g) quantities of grass from turnout to the end of August. In each of 3 years, 60 to 70 January- to March-calving British Friesian cows were used. From calving until turnout to grazing the mean daily DM intakes of silage were 7·2 and 8·9 kg, and of concentrates 8·5 and 4·9 kg for the H12 and L6 groups respectively, giving a mean substitution rate of 0·47 kg silage DM per kg concentrate DM. Mean daily milk yields were 26·7 and 22·9 kg giving a direct response of 0·85 kg/kg additional concentrate DM. Milk from the L6 group had a higher fat concentration and these cows were also lighter at the end of the winter. At pasture, there were no significant interactions for milk variates between winter treatments and grass availability. The stocking rate of cows with restricted grass availability was 0·33 higher from turnout to the end of August. It resulted in a 0·10 proportional reduction in milk yield per cow but per ha there was a 0·21 proportional increase. At pasture, the H12 cows gave more milk at both grass availabilities. The total responses to concentrates were 1·59 and 2·11 kg milk per kg concentrate DM at the ad libitum and restricted grass availabilities respectively. The good response to concentrate coupled with a 0·35 cow per ha increase in annual stocking rate as a result of restricting the grazing area ensured that gross margins and grass utilization were highest for the H12g cows. Conception rates were similar on all treatments and there were no significant differences in live weight at the end of lactation.