bluuebunny/crossref_metadata_2025 huggingface dataset:
The reproductive performance, mothering ability, and productivity of crossbred and Tswana beef cows in Botswana
Authors: Light D. , Buck N. G. , Lethola L. L.
Published: September 2010

The calving rates, survival and growth of calves of Brahman (344), Bonsmara (454), Simmental (601) and Tuli (276) crossbred cows, and pure Tswana (405), were collected for a 7-year period, 1974–80. Calving and survival rates for calves were 0·90, 0·88, 0·87, 0·87 and 0·82; and 0·94, 0·93, 0·96, 0·94 and 0·93, for Simmental, Tuli, Brahman and Bonsmara crossbreds, and pure Tswana, respectively. These differences were not significant (P<0·05).

Calves produced by Simmental ♂ and Bonsmara ♂ crossbred cows were significantly heavier than those from Brahman ♂ and Tuli ♂ crossbred cows (P<0·01), but not from Tswana-sired calves. At weaning, calves from Simmental-cross cows weighed 214 kg, significantly heavier than those produced by any other cow type (P<0·01). Bonsmara- and Brahman-cross cows produced calves weighing 203 and 198kg respectively at weaning, which were also significantly heavier than the calves of Tswana and Tuli crossbred cows (P<0·01), which weighed 187 and 184 kg respectively.

Productivity estimates combining these three traits, and expressed as weight of calf weaned per cow per year, per kg cow weight and per kg metabolic weight of cow, demonstrate the advantages of three of the crossbred cow types over the pure Tswana. Recommendations for the further development of crossbreeding systems in Botswana are made on the basis of this finding.
Some sources of error and possible bias in Danscan ultrasonic measurements of cattle
Authors: Gibson J. P. , Alliston J. C.
Published: September 2010

Photographs of ultrasonic images of 10 animals were taken. Two replicate photographs were taken at each of four body positions (10th rib, 13th rib, 3rd lumbar and hindquarter) on both sides of the body in the morning and the afternoon of the day of scanning. Several measurements were taken on each photograph by an experienced interpreter. Replicate photographs failed to account for all possible sources of measurement error. Since neither time of day nor side of the body affected the mean value, taking observations at different times of the day or on both sides of the body could permit most sources of measurement error to be taken into account. Variation due to errors of measurement and differences among animals are presented. The residual error distribution contained several extreme outliers.

It was concluded that a better understanding of all the sources of bias and error will be needed if ultrasonic measurements are to be more widely used.
Lipid metabolism in finishing bulls and steers implanted with oestradiol-17 β-dipropionate
Authors: Prior R. L. , Smith S. B. , Schanbacher B. D. , Mersmann H. J.
Published: September 2010

Twenty bull calves were assigned to one of four treatment groups: 1) intact bulls; 2) intact bulls implanted with oestradiol dipropionate; 3) steers, and 4) steers implanted with oestradiol dipropionate. Subcutaneous adipose tissue was obtained by biopsy 5 months after implantation. Experimental treatment did not alter (P> 0·05) mean adipose cell volume, diameter or cell number per g adipose tissue. Soluble protein content of adipose cells from bulls was increased by implantation, but not in steers.In vitrorates of fatty acid synthesis were higher in oestrogen-implanted cattle compared with nonimplanted cattle when expressed per g adipose tissue, but not when expressed per cell. Maximal activities of the lipogenic-related enzymes, acetyl coenzyme A carboxylase, adenosine triphosphate-citrate lyase, aconitate hydratase and NADP-isocitrate dehydrogenase were higher in implanted compared with nonimplanted cattle when the activities were expressed per g tissue and acetyl coenzyme A carboxylase and aconitase were also higher when expressed per adipose cell. Bulls and steers had the same basal and stimulated lipolytic rates and implantation of oestradiol dipropionate had no effect on either basal or stimulated lipolytic rate. In this experiment, the oestrogenic implant appeared to have a stimulatory effect onin vitroestimates of lipogenesis.
Beef production from silage 3. The effect of supplements of hay and dried grass on the performance of beef cattle
Authors: Thomas C. , Tetlow R. M. , Gibbs B. G. , Gill Margaret
Published: September 2010

1. The primary growth of perennial ryegrass was cut between 7 and 9 June and ensiled with formic acid at 2·5 1/t. The regrowth was cut on 24 July; part was dried at high temperature (dried grass), the remainder was left to dry in the field (hay). The dried grass (DG) and part of the hay were ground and pelleted, the hay being pelleted alone (PH) or with the addition of formaldehyde at 20 g/kg crude protein (PHF). The remainder of the hay was offered in the chopped form (CH). The four supplements (CH, PH, PHF, DG) were offered at two levels, 6·5 (L) and 130 (H) g dry matter per kg live weight to 54 British Friesian steers (initial live weight, 110 kg) receiving the silage ad libitum.

2. The silage had a high pH and a high proportion of the total nitrogen was in the form of ammonia, indicating poor fermentation. The solubility of nitrogen in the supplements was highest (262 g/kg total nitrogen) in CH, progressively less in PH and PHF and lowest (122 g/kg total nitrogen) in DG.

3. Total dry-matter intake was highest with DG at the higher level of inclusion. Dry-matter intake was significantly higher for PH and PHF than for CH (P < 0·001). However, intake of digestible energy did not differ between hays. Live-weight gain was increased from a low level of 0·24 kg/day (silage alone) by all supplements, but this effect was greater with DG than with the hays (P < 0·001). Level of supplementation increased live-weight gain from 0·54 to 0·74 kg/day.

4. Supplements of dried grass gave higher live-weight gains than did hay made from the same sward. However, the results indicate that supplementation of badly preserved silage with grass hay of good quality can produce acceptable levels of performance of up to 0·70 kg/day in 4-month-old steers. Processing of the hay had little effect on animal performance.
Effect of inclusion of protected and unprotected tallow in the supplement on the performance of lactating dairy cows
Authors: Murphy J. J. , Morgan D. J.
Published: September 2010

Three concentrate mixtures were compared in a replicated 3 × 3 Latin square feeding trial with cows in early lactation to evaluate the effect of inclusion of tallow. The concentrates were based on barley and soya bean meal (223 g crude protein per kg dry matter) with either no tallow addition (control group) or with the addition of a protected tallow premix (0·75 spray-dried formaldehyde-treated tallow, 0·25 casein) or an unprotected tallow premix (0·75 spray-dried tallow, 0·25 casein), both added at 138 g/kg. Each concentrate was given at a rate of 8 kg per cow per day and silage was offered ad libitum. The inclusion of unprotected tallow in the concentrate did not significantly change milk yield, fat concentration, lactose concentration or live weight compared with those in the control group. The inclusion of the protected tallow supplement resulted in significantly higher yields of milk (22·9 kg/day), fat (0·95 kg/day) and lactose (1·05 kg/day) compared with those of the control group (21·3 kg/day, 0·79 kg/day, 0·95 kg/day), whilst milk protein concentration was significantly reduced. A digestibility trial with steers showed that, when hay was given with the diets, inclusion of tallow in the concentrate significantly increased the digestible and metabolizable energy concentration of the diets compared with the control diet, but dry matter, energy and fibre digestibility was reduced.
The effect of protein intake and lactation number on post-partum body weight loss and reproductive performance of dairy cows
Authors: Kaim M. , Folman Y. , Neumark H. , Kaufmann W.
Published: September 2010

In three experiments 250 high-yielding dairy cows were fed for 18 weeks after parturition either a low-protein (LP) diet containing 150 to 160 g crude protein per kg or a high-protein (HP) diet containing 190 to 200 g crude protein per kg. In all three experiments cows were fed an average of 2·6 to 2·9 kg crude protein per day on the LP diet and 3·3 to 3·7 kg crude protein per day on the HP diet. Inclusive of maintenance, crude protein intake was, on average, 71 to 83 g crude protein per kg milk on the LP diet and 84 to 112 g crude protein per kg milk on the HP diet.

Protein intake did not affect the post-partum decrease in body weight; however, cows in their 4th and later lactations lost significantly more weight than cows in their 2nd and 3rd lactations (P < 0·01). Number of lactation did not affect the levels of rumen fluid ammonia or plasma urea, but older cows had significantly higher milk yields than younger ones. In all the experiments the first oestrus was observed, on average, between 38 and 43 days after parturition. The first insemination was carried out, on average, between 69 and 75 days after calving. Protein intake or age did not affect the intervals between parturition and the first observed oestrus or insemination. Proportional conception rates of cows fed the LP and HP diets were 0·566 and 0·431, respectively (P < 0·05). Conception rates of cows in their 2nd and 3rd lactations were 0·582 and 0·515 for cows on the LP and HP diets, respectively, whereas conception rates of cows in their 4th and later lactations were 0·526 and 0·288, respectively (P < 0·02). Within the HP-fed group the difference in conception rate between cows in their 2nd and 3rd lactations and those in their 4th and later lactations was also significant (P < 0·01). The proportion of cows pregnant 126 days after parturition was 0·786 and 0·645 for cows fed the LP and HP diets, respectively (P < 0·05). The proportion of cows in their 2nd and 3rd lactations which were pregnant, was 0·792 and 0·702 for cows of the LP and HP groups, respectively. Pregnancy rates for cows in their 4th and later lactations were 0·769 and 0·515 in the LP and HP groups, respectively (P < 0·05).
Comparative performance of crossbred ewes from three crossing sire breeds
Authors: Cameron N. D. , Smith C. , Deeble F. K.
Published: September 2010

The performance of crossbred ewes sired by Border Leicester (BL), Bluefaced Leicester (BFL) and ABRO Damline (DL) crossing sires was compared. The dams of the crossbred ewes were of three hill breeds (Scottish Blackface, Swaledale and Welsh Mountain). Contemporary comparisons were made on 18 commercial and college farms throughout England and Wales from 1977 to 1981. A total of 1 277 crossbred ewes were involved with data on up to three years' lambings per ewe, giving a total of 3 522 mating records. The analyses were by least squares, fitting constants for terminal ram breed × farm × year of birth of ewe groups, sire breed, dam breed, age of crossbred ewe and all two-way interactions.

The DL crossbred ewes were lighter at mating than the other crossbreds at each age. The proportion of 1-year-old crossbred ewes lambing was highest for the DL (0·78), compared to BFL (0·73) and BL (0·62), indicating earlier sexual maturity. Over all ages, the DL crossbreds were more prolific with 1·79 lambs per ewe lambing compared to BFL (1·63) and BL (1·53) and more lambs were weaned (1·33, 1·29 and 1·19 respectively). The total litter weight at both birth and weaning of the DL crossbreds was greater than the BL crossbreds but less than the BFL crossbreds at each age. For prolificacy and early sexual maturity, the DL cross is superior to both breeds. In overall production, the DL cross had no advantage over the BFL cross, as the litters of the DL crossbred ewes were lighter than the BFL litters at both birth and 10 weeks of age
Follicle curvature score and its relationships with wool production
Authors: Gonzàlez R. , Lombardini A. , Ibañez W.
Published: September 2010

Medium-wool Australian Merino rams were sampled in 1978 and 1979 to estimate the relationships between the follicle curvature score, fleece and body characteristics.

As a high correlation coefficient between two independent observers was found in both years, only one observer was used to correlate follicle curvature score with wool production.

Repeatability of the follicle score between lambs at weaning and 14- to 15-month-old rams was 0·61*** and 0·65***.

Clean fleece weight was significantly correlated with greasy fleece weight (0·8***, 0·9***), clean scoured yield (0·6***, 0·7***), staple length (0·4*, 0·5**) and crimps per cm (-0·3, -0·4*), but the correlation was very low with fibre diameter (0·01, 0·06).

The correlation of clean fleece weight with body weight at 14 to 15 months varied between 0·2 and 0·5 (P < 0·001).

Follicle curvature score was significantly correlated with clean fleece weight (-0·5**), clean scoured yield (0·6***, 0·7***), staple length (-0·4*, -0·7***), fibre diameter (0·3, 0·6***) and crimps per cm (0·4*. 0·6***). Non-significant correlations of follicle curvature score with greasy fleece weight (–0·2) and body weight at 14 to 15 months (–0·04, –0·1) were found.

Depending on whether the proportion of superior 14- to 15-month-old rams which are to be retained for breeding is 0·10 or 0·05, then, according to our data, the proportion of lambs that can be culled at weaning (with an accuracy of P < 0·05) is 0·31 or 0·42, respectively.
A comparison of two-cut and three-cut systems of silage making for beef cattle using two cultivars of perennial ryegrass
Authors: Steen R. W. J.
Published: September 2010

Two randomized-block experiments have been carried out to examine the effects of increasing the digestibility of grass silage offered to beef cattle by harvesting three crops of grass after shorter growth intervals rather than two crops after longer growth intervals. In experiment 1 early-cut silages were harvested on 1 June, 16 July and 24 August, and late-cut silages on 20 June and 22 August 1979. In experiment 2 the early-cut silages were harvested on 19 May, 2 July and 20 August, and the late-cut silages on 5 June and 12 August 1980. Early- and late-cut silages were made from each of two cultivars of perennial ryegrass (cultivars Cropper and Talbot). The silages were unwilted and had formic acid applied at 2.5 1/t fresh crop.

In experiment 1 the silages were offered ad libitum, both unsupplemented and supplemented with 2·2 kg concentrates per head daily, to 88 cattle of mixed beef breeds and mean initial live weight 337 kg, in a 2 × 2 × 2 factorial design. In experiment 2 the silages were offered ad libitum and supplemented with 2·4 kg of concentrates per head daily to 56 Charolais × (Aberdeen Angus × Friesian) cattle of mean initial live weight 351 kg, in a 2 × 2 factorial design. Grass cultivar did not significantly affect silage intake or animal performance but intake, live-weight gain and carcass gain were significantly higher for the early-cut than for the late-cut silages in both experiments. In experiment 1 silage dry-matter intakes were 6·33, 5·12, 5·80 and 4·67 (s.e. 0·124) kg/day; live-weight gains were 0·72, 0·89, 0·47 and 0·76 (s.e. 0·029) kg/day; and carcass gains were 0·46, 0·60, 0·27 and 0·48 (s.e. 0·016) kg/day, for the unsupplemented and supplemented early-cut silages, and the unsupplemented and supplemented late-cut silages, respectively. In experiment 2 silage dry-matter intakes were 5·49 and 4·95 (s.e. 0·056) kg/day; live-weight gains Were 0·95 and 0·76 (s.e. 0·033) kg/day; and carcass gains were 0·67 and 0·50 (s.e. 0·17) kg/day, for the early- and late-cut silages, respectively.
Effects of body condition and environmental stress on ovulation rate, embryo survival, and associated plasma follicle stimulating hormone, luteinizing hormone, prolactin and progesterone profiles in Scottish Blackface ewes
Authors: Rhind S. M. , Doney J. M. , Gunn R. G. , Leslie I. D.
Published: September 2010

In a 2 × 2 factorial experiment, half of each of two groups of ewes in high (20 ewes) or low body condition (20 ewes) were subjected to procedures designed to simulate normal management and climatic stresses, and the effects of these treatments on ovulation rate, embryo survival and endocrine status were investigated.

The mean ovulation rate of ewes in the high condition group was significantly higher than that of ewes in the low condition group (1·8 v. 11) (P < 0·001). Embryo survival rates were unaffected. Neither ovulation rate nor embryo survival were affected by stressful treatments.

Circulating follicle stimulating hormone, luteinizing hormone and prolactin levels were recorded in the peri-ovulatory period. Mean circulating follicle stimulating hormone levels were similar in three of the treatment groups but were generally lower in ewes in the low condition/stressed group. This difference was significant in some of the sampling periods. Neither basal levels of luteinizing hormone nor the size of the pre-ovulatory luteinizing hormone surge were significantly affected by level of body condition or stress but the surge began earlier in ewes in the low condition groups. The difference in timing was not, however, related to ovulation rate. Circulating prolactin levels were consistently and often significantly lower in ewes in poor condition (P < 0·05). Levels were not significantly affected by stress.

While ovulation rate was affected by body condition, the recorded progesterone profiles during the first 2 weeks after mating suggest that luteal function was not affected by any of the treatments applied.
Prediction of the true metabolizable energy concentration in forages for ruminants
Authors: Dewhurst R. J. , Webster A. J. F. , Wainman F. W. , Dewey P. J. S.
Published: September 2010

A model has been developed to predict the true metabolizable energy (ME,) concentration in forages given to ruminants.

The chemical description of forages is based on the concentrations of ash, crude protein, ether extract, sugars and α-glycans, β-glycans and lignin, volatile fatty acids and lactic acid. The model assumes complete fermentation of sugars, α-glycans and lactic acid. The extent of fermentation of β-glycans and crude protein is determined in part by rumen solid-phase outflow rate, which can itself be predicted from dry-matter intake.

The model was tested using 121 graminaceous forages whose chemical composition and concentration of metabolizable energy had been measured in the Feedingstuffs Evaluation Unit at the Rowett Research Institute. The agreement between observed and predicted ME, for all classes of forage was nearly always as good as, or better than, the best prediction from single attributes of food chemistry which could only be determined retrospectively and were not consistent even within classes of forage. The model predicts a decline in ME, with increasing rumen solid-phase outflow rate which is determined mainly by the extent of fermentation of β-glycans.
Studies on lambs from lines genetically selected for low and high copper status 2. Incidence of hypocuprosis on improved hill pasture
Authors: Woolliams J. A. , Woolliams Carol , Suttle N. F. , Jones D. G. , Wiener G.
Published: September 2010

Growth rate and the concentrations of various biochemical constituents were measured in 2 years in lambs from two lines, selected on low (L) and high (H) copper (Cu) concentrations in plasma, and from two unselected pure breeds, Scottish Blackface (B) and Welsh Mountain (W). The lambs grazed improved hill pastures and half were given Cu supplements.

H lambs were always heavier and were fattened for slaughter earlier than were L lambs, differences that were not completely eliminated when supplementary Cu was given. In both years, the improvements in growth rate due to supplementary Cu varied with genetic type (average L 20·5 (s.e. 2·5); H 5·7 (s.e. 2·6); B 25·1 (s.e. 3·7); W 8·1 (s.e. 3·3) g/day). Growth rates of supplemented lambs were L 100 (s.e. 2), H 104 (s.e. 2), B 134 (s.e. 5), W 103 (s.e. 3) g/day.

At 6 weeks of age, unsupplemented lambs trom all genetic types were hypocupraemic and, at all ages, unsupplemented L and B lambs had lower concentrations of Cu in plasma and superoxide dismutase (SOD) activity than had unsupplemented H and W lambs. Supplemented lambs always had greater concentrations of Cu in plasma and SOD activities than had their unsupplemented counterparts. Supplementation increased the haemoglobin concentration for B (in year 2) and L lambs but not for H and W lambs. Cholesterol concentrations in plasma were unaffected by selection but were slightly higher in unsupplemented lambs. The concentration of total protein and the activity of aspartate transaminase were unaffected by genotype or Cu supplementation. In the liver of lambs at slaughter, the concentration of Cu was lower for unsupplemented lambs and inversely related to the concentration of iron.

It was concluded that (i) genotype was an important determinant of hypocuprosis; (ii) the degree of hypocuprosis could not be predicted from herbage analyses alone, but instead may be predicted from biochemical assessment of the lamb; and (iii) the dose of Cu supplement used was inadequate for L and B lambs and recommended levels could be increased, within limits, without risk of toxicity.
Effect of fish meal on the mobilization of body energy in dairy cows
Authors: Ørskov E. R. , Reid G. W. , Tait C. A. G.
Published: September 2010

Thirty-two Friesian cows in early lactation were divided into four treatment groups to receive ad libitum a mixed diet consisting of silage (0·70) and grain-based concentrate (0·30). Fish meal was subsequently mixed into the diet at levels of 0, 40, 80 and 120 g/kg to provide crude protein concentration (g/kg dry matter) in the complete diets of 156, 181, 200 and 212 respectively. In the 2nd week after calving the yields of fat-corrected milk (FCM) were 28·5, 29·2, 32·0 and 34·9 kg/day for the four levels respectively; at this time, food intake was sufficient only to meet the calculated energy requirement for 15 kg FCM per day. Due to recurring problems with ketosis on the diet containing 120 g fish meal per kg, this treatment was terminated and the experiment continued for 15 weeks with the groups receiving 0, 40 and 80 g/kg fish meal supplements. During this time average yields of FCM were 23·5, 25·6 and 28-0 kg FCM per day respectively and energy intakes were calculated to be sufficient to meet the requirement for 18 kg FCM per day.

It appeared possible to increase milk yield by stimulating fat mobilization through giving undegraded protein supplements to underfed cows in early lactation. However, when an excessive mobilization occurred with a high supplement, and when the animals were yielding 15 to 20 kg FCM more than their metabolizable energy intake was calculated to sustain, some cows became ketotic.
Effect of allyl-trenbolone on the attainment of puberty in gilts treated with oestradiol
Authors: Yang H. , Varley M. A. , Rodway R. G.
Published: September 2010

Sixty Large White d♂ × (Large White ♂ × Landrace ♀) pre-pubertal gilts were allocated at random to one of five treatments. Treatment consisted of a combination of three factors to induce puberty and maintain cyclicity: the administration of exogenous oestradiol benzoate (OB), the application of an orally active synthetic progestagen, allyl-trenbolone (AT), and exposure to mature boars. Treatment A gilts were given OB at 160 days of age (15 μg/kg body weight). This was followed by the administration of 20 mg/day of AT from 166 days of age for 18 days. These gilts were also allowed exposure to a mature boar for 30 min/day from 160 days of age until they were mated. Treatment B gilts were given OB at 160 days of age and were allowed boar exposure from 160 days of age but were not given AT. Treatment C gilts were given OB and AT but were not allowed exposure to a mature boar. Treatment D gilts were not given OB at the beginning of the experiment but were given AT for 18 days from 166 days of age and were allowed boar exposure. Treatment E gilts were not given any exogenous hormones but were allowed boar exposure from 160 days of age. The dose of OB was split equally into three bolus injections given on consecutive days beginning at 160 days of age. All gilts were mated twice during the first 2 days of their second oestrous period, and were slaughtered at either 25 days post coitum or at 220 days for anoestrous gilts.

The percentages of OB-treated gilts with normal oestrous cycles (oestrous cycles of between 15 and 30 days from one oestrus to the next) were: 91·7%(11/12), 45·5%(5/ll) and 58·3%(7·12) for gilts in treatments A, B and C respectively (P < 0·05). The OB-treated gilts (treatments A, B and C) attained puberty at a significantly younger age than did the control gilts in treatment E (F < 0·05). No significant differences were found in ovulation rate and the percentage embryo survival between treatments.

The results demonstrate that the combination of AT and boar exposure was an effective means of maintaining oestrous cycles in OB-treated gilts.
A note on the effect of the dry-matter concentration in forages on water consumption of yearling steers
Authors: Sekine J. , Asahida Y.
Published: September 2010

Water consumption has been considered to be a function of dry-matter (DM) intake (Leitch and Thomson, 1944; Winchester and Morris, 1956). Thus, water requirement for ruminants has been presented as kg per unit of DM intake (Agricultural Research Council (ARC), 1965; Japanese Agricultural and Fishery Technology Council, 1974). Little work, however, has been done on the effect of the DM concentration of a diet on water consumption in cattle.
Factors affecting culling and survival during rearing and first lactation in purebred and crossbred dairy cattle
Authors: Hocking P. M. , McAllister A. J. , Wolynetz M. S. , Batra T. R. , Lee A. J. , Lin C. Y. , Roy G. L. , Vesely J. A. , Wauthy J. M. , Winter K. W.
Published: September 2010

Factors affecting survival to first and second calving and successful completion of a > 168-day first lactation were assessed in 3075 purebred and crossbred dairy heifer calves. Growth, disease, frequency, reproduction, calving, udder and lactation traits were examined in females of a breeding project conducted jointly at five research stations (herds) of Agriculture Canada. Losses included mortalities and non-discretionary culling. About 0·23 of potential heifers were culled or died before first calving, and 0·25 of those calving once did not calve a second time. Results from retrospective selection index and stepwise linear logistic analyses showed that predictability of culling prior to 308 days post partum was poor. With few exceptions, survival rates from birth to 82 weeks varied among herds (P < 0·001) and among lines (P < 0·05). Heterosis for the probability of completing a lactation and of survival to second calving was significant (P < 0·05) and positive (0·05 to 0·09). Heavier heifers were more likely to survive to first calving. Sire's estimated breeding values (SEBV) for milk yield and fat, protein and lactose concentration were not important in predicting survival to first calving. SEBV lactose was negatively associated with survival after first calving as predicted from data available at most preceding stages of life. An age greater than 82 weeks at last insemination was associated with a lower probability of survival to first and second calving (P < 0·001). Cows which conceived for a second gestation and subsequently aborted had a lower probability of survival to second calving than cows which did not abort (0·57 v. 0·76, P < 0·01). The only continuous traits with large effects on survival or the probability of completing a first lactation were days to last insemination (a measure of fertility) and milk yield. It was concluded that (1) there is considerable scope for improved management to increase survival in early life by prevention of calfhood diseases; (2) losses in early life do not bias sire evaluation on first lactation records; (3) improved reproductive success would greatly enhance overall survival rates; and (4) crossbreeding could have a large impact on overall herd profitability through increased survival.
Effect of straw quality and ammonia treatment on voluntary intake, milk yield and degradation characteristics of faecal fibre
Authors: Ørskov E. R. , Tait C. A. G. , Reid G. W. , Flachowski G.
Published: September 2010

Thirty-two Friesian cows in early lactation were given one of tour completely mixed diets based on equal proportions of barley straw and concentrate. Two varieties of barley straws had been identified as varying in degradation characteristics (Corgi and Gerbel) and the straws were either given untreated or treated with anhydrous ammonia. The ad libitum intake for 10 weeks closely reflected degradation characteristics. For Corgi, treated and untreated and Gerbel, treated and untreated the 48·h degradabilities were 71·9, 66·8, 61·9 and 52·2 (g/100 g) respectively. The voluntary intakes of dry matter were 17·1, 14·8, 15·0 and 13·1 (s.e. 0·51) kg/day and average yields of fat-corrected milk for 10 weeks were 26·7, 21·5, 22·6 and 22·4 (s.e. 1·0) kg/day respectively.

It was calculated that the differences between actual digestibility and potential degradability were greatest for ammonia-treated straws. Also it was observed that the degradability of faecal dry matter was greater from animals given ammonia-treated straws.
Effect of castration and an anabolic implant on growth and serum hormones in cattle
Authors: Henricksi D. M. , Gimenez T. , Gettys T. W. , Schanbacher B. D.
Published: September 2010

In the present study, a commercially available anabolic implant containing trenbolone acetate and oestradiol-17p was investigated in intact and castrated bulls. Measurements of growth rate, serum hormones and metabolites in both phenotypes, and testicular development and function in bulls, were obtained. The experimental objectives were realized in a 2 × 2 factorially designed experiment utilizing eight Angus-sired crossbred bulls and eight similar steers castrated at 7 months of age. Half of each group were implanted with 140 mg trenbolone acetate plus 28 mg oestradiol-17β. Body weights were monitored every 7 days and plasma samples were obtained at 28-day intervals from 9 to 15 months of age. In the implanted groups, mean concentrations of plasma trenbolone and oestradiol-17p were 380 ng/1 and 31 ng/1, respectively. Trenbolone concentrations were undetectable in both non-implanted groups, and plasma oestradiol-17β was less than half that in implanted animals. While plasma GH concentrations were stratified according to implant treatment, they did not differ among the groups. Cortisol levels showed phenotype × implant interaction; implanted steers and non-implanted bulls had lower concentrations than non-implanted steers and implanted bulls. The implant resulted in no significant changes in gross testicular measures in the bulls but did affect the testosterone response to a GnRH challenge and basal plasma concentrations of testosterone were reduced. Plasma urea concentrations were reduced by the implant, but sex phenotype had no effect. Over the 175-day trial, implantation did not significantly improve the growth rate of bulls, except during the first third of the experiment. In contrast, implantation improved the growth rate of steers over the entire experiment, although implanted steers still grew more slowly than either implanted or non-implanted bulls. It can be concluded that the endocrine status of the young bull is set for a fast growth rate, making improvements via an anabolic implant marginal, except in the immature animal.
Development of some behaviour patterns in piglets under semi-natural conditions
Authors: Newberry R. C. , Wood-Gush D. G. M.
Published: September 2010

A study was made of the behavioural development of domestic piglets living in a spacious, ecologically and socially diverse environment. The effects of age and sex of piglet on the frequencies of 30 behaviour patterns over the period from birth to 14 weeks of age were examined through focal animal sampling of 35 piglets from six litters. It was found that the frequencies of lying and standing in contact with other pigs declined significantly with age while walking, wagging the tail, sniffing the ground and the biting of objects increased with age (P < 0·05). Trotting, scampering and circling with other piglets were most frequent between 2 and 6 weeks of age. The frequencies of shaking the head, ‘quacking’, rooting, shovelling, and chewing at, and shoving, other pigs also varied significantly with age. Females wagged their tails more frequently than males whereas males circled, shoved and mounted more frequently than females (P < 0·05). Results are discussed with reference to the behaviour of young pigs kept under intensive housing conditions.
Sampling of digestive contents by ileal cannulation in the rabbit
Authors: Gidenne T. , Bouyssou T. , Ruckebusch Y.
Published: September 2010

A technique is described for the collection of digestive contents with a glass T-shaped ileal cannula, in rabbits fed ad libitum. Repeated samples of ileal contents were easily obtained by gravity from conscious animals lying in a hammock for 1 h, twice a week, over a period of 2 months. Analysis of the ileal contents showed no diurnal variations in concentrations of crude protein, neutral-detergent fibre, ammonia, and total short-chain volatile fatty acids. The fresh weight output was maximal at 09.00 h and minimal at 03.00 h. The transit time of phenol sulphone phthalein between mouth and ileum was 75 (s.d. 14) min and did not vary according to the time of day when measured (08.00 to 12.00 h, 14.00 to 18.00 h, 20.00 to 24.00 h).
An assessment of the relationship between tissue growth patterns and selected hormone profiles among sex phenotypes in cattle
Authors: Gettys T. W. , Henricks D. M. , Schanbacher B. D.
Published: September 2010

The four sex phenotypes were used to study the relationship between carcass composition and serum profiles of hormones thought to affect growth. Forty calves (10 bulls, 10 steers, 10 heifers and 10 ovariectomized heifers) from Hereford dams crossed with Simmental-Hereford bulls (¾ Simmental-¼ Hereford) were given a high energy diet from 10 to 16 months of age. Sequential blood samples (20-min intervals) representing 6-h windows were obtained from each animal at the outset of the experiment and at 28-day intervals thereafter. Samples were assayed for growth hormone (GH), insulin, triiodothyronine, cortisol, testosterone, oestradiol-17β, urea and albumin. The 9-10-llth rib was dissected into fat, lean and bone, and chemical analysis was performed on the dissected soft tissue. Bulls accumulated more lean tissue and less fat than any other group. Heifers and ovariectomized heifers accumulated the least lean and most fat while steers were intermediate between bulls and the two heifer groups. Bulls may have accumulated more lean and less fat than the heifers due to higher GH and testosterone concentrations, and lower circulating concentrations of cortisol and insulin. The known function of these four hormones and their relative concentrations between bulls and the two female groups were consistent with their suggested role in the relative carcass compositions. The intermediate composition of the steer carcass may have resulted from an interplay between the proteogenic influence of higher GH concentrations, the proteolytic influence of elevated cortisol, the absence of testosterone and the lipogenic influence of higher insulin.
Differential rates of genetic change and genotype × environment interactions in six pig breeding company populations and a purebred Large White population
Authors: Evans D. G. , Kempster A. J. , Steane D. E.
Published: September 2010

Differential rates of genetic change in litter productivity, growth and carcass traits were estimated for the pig populations of six British breeding companies from their relative performance between 1972 and 1981 in the Meat and Livestock Commission's Commercial Pig Evaluation. Pigs were grown on one of two feeding regimens and slaughtered at one of three live weights (61, 93 and 118 kg).

Important differentials were found for a number of traits. Annual rates of change in litter size at birth differed by 0·34 pigs between the two extreme populations. The range between populations for live-weight daily gain (ad libitum feeding) was 20 g, for lean weight daily gain (restricted feeding) it was 6 g, and for lean weight food conversion (feeding regimens pooled) it was 28 g food per g gain. The average annual rate of change of the six company populations was compared with the rate achieved by the purebred Large White breed over the period 1972 to 1977. For mean piglet birth weight the rate was 30 g higher for the company populations, whilst for carcass weight daily gain it was 24 g higher.

There was little evidence for population × feeding regimen interactions except that companies ranked differently in average daily food intake, live-weight daily gain and carcass weight daily gain on the two feeding regimens. On limited evidence, population × slaughter weight interactions were also unimportant.
Effect of air temperature on the abomasal and small intestinal digestion of a milk substitute diet given to young calves
Authors: Cockram M. S. , Rowan T. G.
Published: September 2010

Twelve Friesian calves were each fitted with an abomasal cannula. The calves were placed in a controlled environment chamber and given a milk substitute diet in buckets at 12-h intervals. The calves were exposed to air temperatures of 25°C from 4 to 10 days of age, 5°C from 11 to 14 days of age, and 25°C at 15 days of age. At 9, 10, 11, 14 and 15 days of age, the abomasal contents of the calves were sampled at 2-h intervals and the temperature and pH of the abomasal contents were recorded at 40-min intervals for a period of 12 h. The rectal and abomasal temperatures of the calves were lower at 11 days of age than at 10 days of age, and were greater at 15 days of age than at 14 days of age (P < 0·05).

In a similar experiment four Friesian calves were each fitted with an ileal re-entrant cannula. The calves were exposed to air temperatures of 25°C from 5 to 19 days of age, 5°C from 20 to 26 days of age, and 25CC at 27 days of age. At 18, 19, 20, 26 and 27 days of age the ileal contents of the calves were collected and sampled for a period of 12 h.

No significant effects of the air temperatures of 25° and 5°C on the abomasal digestion (acidity and proteolytic activity of the abomasal contents) and ileal apparent digestibility of the diet were found.
Relationship between muscle and bone development of the hind limb in lambs of different breeds
Authors: Anous M. R.
Published: September 2010

A total of 52 ram lambs of different morphological types slaughtered at a comparable stage of body development (carcass weights = 19·5 (s.d. 3·10) kg) were used to study the variation in the relationship between muscle and bone development in the hind limb using multivariate techniques. Development of individual muscles was expressed relative to the weight of the major bone to which they are closest, considered here as their carrier bone.

Variability of muscle: bone ratios of individual muscles varied considerably from one muscle to another. The coefficient of variation (CV) ranging from 0·111 to 0·462 (average CV = 0·199). Relative to the same bone, the variability of muscle: bone ratios for each of the three anatomical regions of the hind limb was still important. This suggests that variability may be due to other factors besides muscle weight, such as bone shape.

The correlation between the various muscle: bone ratios was low in some cases. However, a significant association existed between muscle: bone ratios of individual muscles and the total muscle: bone ratio in the hind limb which indicated that some muscle: bone ratios can be used as indicators of muscling in the selection of meat animals such as m. semimembranosus/femm, m. gluteobiceps/femur, m. adductores/'femur and m. semitendinosus/femur.

The most discriminant variables of the population in multivariate analysis were m. soleus/tibia, m. extensor digitorium lateralis/tibia, m. quadmtus femoris/coxal, m. gemelli/coxal and m. vastus medialis/femur. It was also possible to distinguish the different morphological types of the different breeds by the values of the ratios between these variables.
Variability of litter size of french sheep breeds following natural or induced ovulation
Authors: Bodin L. , Elsen J. M.
Published: September 2010

The assumption that observed values for litter size result from a set of thresholds which impose a discontinuity to the visible expression of a continuous underlying variate has been tested using data from the French sheep recording scheme: 629 724 natural lambings for 32 different pure breeds and 66 379 litters obtained after synchronization treatment in 15 breeds. Frequencies of single, twin, triplet and higher-order births varied regularly with litter size within each fecundation type. The coefficient of variation of litter size was remarkably constant from breed to breed under both natural (0·35 to 0·40) and induced lambings for which it was higher (0·40 to 0·45). The regression of the difference between the first two thresholds of an underlying normally distributed variate on prolificacy was slowly negative for natural fecundation, but not significant for induced fecundation. A significant effect of fecundation type was found, resulting in a lower incidence of induced than of natural twin litters for the same level of prolificacy. Multivariate polynomial regression of frequencies on natural and induced prolificacy was used to predict expected frequencies of litter size and the proportion of lambs of each birth type.
An assessment of optimal air temperatures in pig houses by the quantification of behavioural and health-related problems
Authors: Geers R , Dellaert B. , Goedseels V. , Hoogerbrugge A. , Vranken E. , Maes F. , Berckmans D.
Published: September 2010

Air temperatures were measured every 2 h in 12 growing-finishing pig houses. All houses were operated on the all-in, all-out, principle. Data were collected for two fattening periods in each house. Stocking density, feeding system, pig type, and the farmer's skill were standardized. Every 2 weeks, the houses were visited and live weight, mortality rate, the incidence of coughing and tail biting, and the extent of dirty lying areas were recorded.

Air temperature limits could be isolated from the complex of factors affecting behavioural and health problems of pigs observed within these experiments. Sensitive periods within the growth period of the pigs seem to exist. At the onset of the fattening period (20 to 30 kg), pigs which have been transported from other farms need special care. During summer, mortality rate was lowered when the periodicity of the temperature cycles was lowered for 40- to 50-kg pigs, whereas for heavier pigs the mean maximal air temperature was important also. With respect to coughing, a statistically significant negative relation with the air temperature in the pig house was found for all weight classes, with interactions from the number of different temperature cycles within a 24-h period. In order to avoid dirty lying areas for 20- to 40-kg animals, air temperatures should be between 20 to 24°C, whereas for diarrhoea, animals of 40 to 50 kg were especially sensitive to the occurrence of low air temperatures. For minimizing tail biting, an optimal air temperature range of 20 to 22°C is suggested.
A note on the effect of feeding cimaterol on some endocrinological parameters and growth in different types of finishing beef bulls
Authors: Fiems L. O. , Decuypere E. , Boucque Ch. V.
Published: September 2010

Investigations were made of the effects of the fi-agonist cimaterol on the growth and hormone status of normal and double-muscled Belgian White-blue bulls. Results indicated that repartitioning effects of this agonist may in part be mediated indirectly through an alteration in the levels of metabolic hormones and that the growth promoting effect is transient.
The effect of concentrate: silage ratio and of hoof trimming on lameness in dairy cattle
Authors: Manson F. J. , Leaver J. D.
Published: September 2010

During weeks 3 to 26 of lactation, two groups of 24 cows were offered either a 60:40 (high) or a 40:60 (low) ratio of concentrate dry matter:silage dry matter. The 40:60 diet was restricted to give the same daily metabolizable energy and crude protein intake. The hooves of half the cows on each diet were trimmed prior to the experiment, the other half remaining untrimmed. The high concentrate ratio significantly increased locomotion score (high scores indicating poorer locomotion), and the number and duration of clinical cases of lameness. Trimming of hooves significantly reduced the number and diiration of clinical cases. Hoof growth was significantly increased by trimming. Hoof hardness was significantly reduced by the high concentrate ratio. The low concentrate ratio had 8/24 cows lame for an average of 3·3 weeks compared with 11 cows for 3·9 weeks on the high ratio. There were 7/24 trimmed cows lame for 3·1 weeks compared with 12 untrimmed cows lame for 4·2 weeks. The main hoof lesions were solar ulcers and heel erosion. There was no significant effect on milk yield, but milk protein was signficantly increased by the high concentrate ratio. Condition score was significantly negatively correlated with locomotion score.
Depression of dry-matter and water intake in Boran cattle owing to physiological, volumetric and temporal limitations
Authors: Nicholson M. J.
Published: September 2010

Dry-matter (DM) intake and water consumption were recorded in Borana cattle (Bos indicus) which were subjected to infrequent watering regimes, prolonged walking and night-enclosure. DM intake and water intake were depressed in cows watered every 2nd day (0·04 and 0·16 respectively) and in cows watered every 3rd day (0·1 and 0·3 respectively) as proportions of the food and water intake of daily watered cows. DM intake was further reduced by proportionately 0·05 as a result of a 40-km walk every 3rd day throughout the dry season and by 0·05 as a result of night-enclosure. Digestibility of food was unaffected by treatments. Water intake increased in some months as a result of walking but not as a result of night-enclosure. It is thought that DM intake was depressed with decreasing frequency of watering owing to the physiological effects of dehydration resulting in inappetence. Water consumption fell owing to the constraint imposed by rumen volume at drinking. Walking and night-enclosure independently reduced DM intake as a result of the greatly decreased time available for grazing.
Plasma β-endorphin and cortisol concentrations in lambs after handling, transport and slaughter
Authors: Fordham D. P. , Lincoln G. A. , Ssewannyana E. , Rodway R. G.
Published: September 2010

The effects of the routine stressful stimuli of handling, transport and slaughter on the plasma concentrations of cortisol and β-endorphin have been studied in lambs. Blood samples were obtained from group 1 lambs after rounding up, after transport and at slaughter. Group 2 lambs were treated similarly except that blood was collected only at slaughter. Group 3 lambs served as controls and were blood sampled twice daily for 5 days to accustom them to handling before being slaughtered. Plasma cortisol and β-endorphin concentrations were increased above control levels by rounding up and transport, and were further increased at slaughter. Group 3 lambs, however, had very much lower β-endorphin levels at slaughter than the other two groups, although their cortisol levels were similar, β-endorphin concentrations declined during the 5-day blood sampling period in group 3 animals but cortisol levels were unchanged. The results suggest that although levels of both hormones are increased by stress, they are not necessarily released concomitantly.