bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of castration of fallow deer (Dama dama) on body growth and venison production
Authors: Mulley R. C. , English A. W.
Published: September 2010

Castration of fallow deer (Dama dama) at 7 months of age resulted in a depressed growth rate to slaughter at 20 months of age, compared with entire bucks. The castrated bucks were significantly lighter at 15 and 20 months of age respectively (P < 0·001). The mean carcass weight of castrated bucks was 6·2 kg lighter and their dressing proportion 0·07 lower than entire bucks. The potential loss of income per carcass is equivalent to A$27·00 per castrated buck at 1984 prices, with a further potential loss of A$30·00 per head from velvet antler production prior to slaughter, if this is deferred until 2 years of age. It is suggested that the only advantage that castrated bucks would have over dean tiered entire bucks occurs during the rutting period of 3 to 6 weeks from early April, when entire bucks are extremely aggressive, and difficult to confine and transport without risk of injury and bruising of carcasses.
The effects of oestradiol treatment on activity, growth and survival in neonatal piglets
Authors: Hughes P. E. , Pearce G. P. , Baguio S. S.
Published: September 2010

Two experiments were conducted to elucidate the effects of intra-muscular injection of oestradiol within 1 min of birth (experiment 1) or within 4h of birth (experiment 2) on piglet activity, growth and pre-weaning survival rate. In experiment 1, 248 piglets (25 litters) were alternately injected within litter at birth with either 1 ml peanut oil/saline solution or 0·1 mg oestradiol benzoate in this carrier solution. The subsequent behaviour, growth and survival of these piglets were recorded. Experiment 2 used 38 litters (385 piglets), these being treated by litter with either of the same two treatments as soon after birth as they were found (approx. range 0 to 4 h). Piglet survival data were collected from this field trial. Oestradiol treatment significantly reduced the intervals from birth to reaching the udder (596 v. 740 s, P < 0·05) and from birth to first sucking (1060 v. 1497 s, P < 0·01) relative to control piglets in experiment 1. Treatment had no significant effect on pre-weaning growth rate (experiment 1), but did tend to reduce early postnatal mortality rate in both experiment 1 (7·2 v. 2·4% for control and oestradiol-treated piglets respectively) and experiment 2 (13·0 v. 10·2% for control and oestradiol-treated piglets respectively). It is concluded that oestradiol treatment at, or soon after, birth induces short-term hyperactivity in piglets. This may subsequently be reflected in an improvement in pre-weaning survival rate of piglets, although further data are required to confirm this conclusion.
Social hierarchy and feeder access in a group of 20 sows using a computer-controlled feeder
Authors: Hunter E. J. , Broom D. M. , Edwards S. A. , Sibly R. M.
Published: September 2010

Twenty pregnant sows sharing a double-entry back-out Pig Code feeder with a similar group of 20 were observed over six 24-h feed cycles by a combination of direct observation and video recording. The group had access to an area of 47 m2. Sows were fed once a day on a pelleted diet and water was continually available. Feeding order was relatively constant from day to day, and was positively correlated with parity. A social hierarchy based on displacements and attacks within pairs of sows was found to be basically linear, with the exception of six reversals of dominance. Social hierarchy was positively correlated with feeding order overall, but this was not the case for the latter half of the feeding order. This was partly due to disruption of feeder use by non-feeding visits made by early-feeding dominant sows. Overall the results showed that older sows with more experience of the feeder in two or three previous parities were higher in the feeding order and social hierarchy than younger sows, and may exclude them from the feeder by repeated non-feeding visits.
Relationships between cardio-respiratory parameters and draught work output in F1 crossbred dairy cows under field conditions
Authors: Zerbini E. , Gemeda T. , O'Neill D. H. , Howell P. J. , Schroter R. C.
Published: September 2010

Cardio-respiratory and mechanical work output variables were measured for four F1 crossbred dairy cows (average weight 475 kg) over a range of work levels. Resting (standing prior to exercise) heart rates (average 62 beats per min) and respiratory rates (average 21 breaths per min) were similar to those previously reported for cattle of similar weight. Minute ventilation was 0·146 l/min per kg. Resting oxygen uptake (average 0·0057 l/min per kg) was higher than values that have been reported for cattle under more relaxed conditions.

The cows were exercised on an oval track by undertaking two bouts of activity for 500 m with a 5-min intervening recovery period. Walking increased minute ventilation by approximately 60 I/min and heart rate by 30 beats per min. Pulling a loaded sledge increased these variables further to approximately 200 l/min and 135 beats per min at 32 kg/min (530 W), the highest work level studied. The calculated oxygen pulse was 72 ml per heart beat, with maximum oxygen consumption approximately 9 l/min.

Overall ivorking efficiency increased with work level to a maximum of approximately 26% at the highest work level. At this level the cows were pulling proportionately about 0·14 of their body weight.

During periods of recovery after work, the cardio-respiratory parameters varied as would be expected and recovery was usually complete within 7 min.
The effect of dietary inclusion of yeast culture (Yea-Sacc) on patterns of rumen fermentation, food intake and growth of intensively fed bulls
Authors: Mutsvangwa T. , Edwards I. E. , Topps J. H. , Paterson G. F. M.
Published: September 2010

The effects of a barley beef diet without (control) and with a yeast culture (YC) on rumen fermentation, in vivo diet digestibility, nitrogen retention, live-weight gain and food intake were evaluated using 13 Limousin × British Friesian bulls per treatment. The YC was composed of the yeast species Saccharomyces cerevisiae and its growth medium dried in such a manner that it maintained its fermentative capacity. The addition of YC significantly increased the concentration of acetate (P < 0·05) while propionate concentration tended to be higher for bulls given YC (P > 0·05). The acetate: propionate ratio remained unchanged. Concentration of total volatile fatty acid (VFA) was significantly higher in YC bulls compared with control bulls (P < 0·05). The in vitro studies using the Menke gas test confirmed these findings. Mean in vitro gas production in bulls receiving YC was lower than that in the controls (P < 0·05) and methane production was significantly reduced by the addition of YC after 12h (P < 0·01). Ruminal ammonia concentrations were not affected by treatment but ruminal pH was significantly depressed by the addition of YC (P < 0·05).

Apparent digestibility of dry matter, organic matter, crude protein and neutral-detergent fibre were unaffected by treatment but tended to be higher with the control diet. Nitrogen retention was not affected by the addition of YC and mean values for allantoin excretion and plasma urea were similar.

In a 28-week feeding trial, dry-matter intake was significantly greater for bulls given YC (5·55 kg/day) than for control bulls (5·32 kg/day, P < 0·05) but average daily gain, 1·55 and 1·58 kg/day for control and YC respectively, and food conversion efficiency were not improved significantly by YC (P > 0·05).
Wool follicle development, wool growth and body growth in lambs treated from birth with recombinantly derived bovine somatotropin
Authors: Sun Y. X. , Michel A. , Wickham G. A. , McCutcheon S. N.
Published: September 2010

The effect of recombinantly derived bovine somatotropin (bST) administration on wool follicle populations, wool growth and body growth was examined in young lambs. Romney × (Border Leicester × Romney) lambs were treated with bST at doses of 0·1 or 0·3 mg/kg live weight per day, or with excipient, commencing on the day of birth and continuing at weekly intervals until the last injection was given at 11 weeks of age. Concentrations of immunoreactive somatotropin in plasma were 19·2 (s.e. 2·1), 65·2 (s.e. 2·8) and 74·7 (s.e. 4·8) μgll in the control, low dose bST and high dose bST groups, respectively. Somatotropin treatment did not alter the density of primary (P) or secondary (S) follicles in the skin, or the S/P ratio, as measured by histological examination of mid-side skin biopsy samples at 14 weeks of age. Mid-side greasy and clean wool growth during weeks 2 to 14 of the study were increased (P < 0·05) in bST-treated lambs but treatment had no effect on wool growth during the immediate post-treatment period (weeks 14 to 22), or on yearling fleece weight or wool quality characteristics. Body growth was not altered by bST administration. It is concluded that bST treatment stimulates wool growth even in very young lambs but, contrary to the results of a previous study, does not alter the development of wool follicle populations.
The effect of active immunization against gonadotropin-hormone-releasing-hormone on growth performance and sample joint composition of bulls
Authors: Lobley G. E. , Connell A. , Morris B. , Anderson R. , Clayton J. , Williams P. E. V. , Nevison I. M.
Published: September 2010

Forty-six Simmental × British Friesian bull calves were allocated to six treatment groups. In four groups (each of eight animals) half the animals were given a prime injection of gonadotropin-hormone-releasing-hormone (GnRH) either as the decapeptide or as an octapeptide (residues 3 to 10) conjugated to egg albumen. Prime injection times were at 3, 4, 5 or 6 months of age. All animals were boosted with a GnRH conjugate, similar to that used for the prime injection, at 8 months. At 8 months, six other animals were surgically castrated while the remaining eight were left as untreated bull controls. Weight gain and consumption of a barley-based diet offered ad libitum were recorded for individual animals. Blood samples were taken at a minimum of fortnightly intervals and the serum analysed for antibody titre against GnRH, testosterone and insulin-like growth factor 1 (IGF-1). Animals were slaughtered at 12 months and chemical analyses performed on the dissectible material of the 10th rib for protein, lipid, ash and water content. Greater antibody titres and a longer period of low serum testosterone were achieved with the octapeptide conjugate compared with the decapeptide. Serum IGF-1 slowly decreased following both surgical- and effective immuno-castration. There were no significant differences in food intake between the groups. Both steers and the more responsive immunocastrates had higher fat (P < 0·01), lower protein (P < 0·05) and water concentrations (P < 0·01) in tissues from a rib sample joint compared with untreated bulls. As immuno-responsiveness decreased there were indications of compensatory changes in body composition. The technique may be applicable during periods of, for example, mixed grazing for bulls.
Calcium hydroxide treatment of malt distillers' grains 2. Effects on apparent digestibilityin vivo, intake and performance in sheep
Authors: Offer J. E. , Offer N. W.
Published: September 2010

The effects of calcium hydroxide (Ca(OH)2)treatment of malt distillers' grains (MDG) on apparent digestibilityin vivo, food intake and lamb performance were measured in three experiments. Experiment 1 measured effects on intake and apparent digestibility of wet MDG either untreated (C), mineralized with a high-calcium mineral (M), Ca(OH)2treated at ambient temperature (L) or at 70°C for 72 h (LH) and offeredad libitumto mature wether sheep (approx. 75 kg live weight). Dry matter (DM) intakes for MDG were 1251,1585,1838 and 1889 (s.e. 93) g/day for C, M, L and LH respectively when given with 780 g DM per day of a standard complete diet (diet A). Corresponding values for whole diet organic matter (OM) apparent digestibility when MDG was given at a fixed rate (1250 g DM per day) with a standard diet (660 g DM per day diet A) were 049, 049, 0·58 and 0·60 (s.e. 0·008) respectively. Experiment 2 compared mineralized wet MDG (M) with a prototype dried food made from Ca(OH)2-treatedensiled MDG (neutralized with NaOH before treatment) held at 60°C for 18 h before drying (NID) and a proprietary lamb finishing compound (PC). The supplements were offered at an increasing rate (350 g DM per day to 1200 g DM per day) to 30 Blackface lambs of approximately 31 kg initial live weight, penned in pairs, and givenad libitumaccess to hay and water. Mean DM intakes (g DM per day) to day 60 for supplements were 925, 750 and 934 (s.e. 19) and for hay were 258, 200 and 311 (s.e. 17) for NID, M and PC respectively. Corresponding values for live-weight gain (g/day) were 136, 123 and 130 (s.e. 11); for condition score (day 59) were 3·9, 3·6 and 4·0 (s.e. 0·06) and for number of lambs finished at day 60 were 8, 2 and 10. Experiment 3 evaluated the apparent digestibility and effects on rumen function of NID, M and PC fed at a fixed rate with chopped hay (804 g DM per day supplement + 396 g DM per day hay) to rumen fistulated wethers (approx. live weight 70 kg). Apparent digestibility values for OM were 0·63, 0·53 and 0·65 (s.e. 0·015) and for neutral-detergent fibre were 0·69, 0·55 and 0·57 (s.e. 0·037) for NID, M and PC respectively. Rumen pH, volatile fatty acid concentrations or hay digestibility in sacco were not significantly affected by supplement. Ca(OH)2treatment greatly improved the nutritional characteristics of MDG giving substantial improvements in apparent digestibility, intake and performance.
The response of weaner pigs to a choice of foods differing in protein content
Authors: Bradford M. M. V. , Gous R. M.
Published: September 2010

Two experiments were designed to test the hypothesis that young growing pigs between 7 and 25 kg live weight are capable of selecting a diet which closely matches their changing requirement for amino acids, when offered a choke between two balanced foods differing only in their protein content. In the first experiment, three single-food treatments (8·6,11·7 and 17·4 g lysine per kg food) and one choice-feeding treatment (8·6 v. 17·4 g lysine per kg food), were used. In the second experiment, three foods of similar nutrient composition (approx. 14·7 g lysine per kg food) were formulated using different ingredients (fish meal, soya-bean oilcake meal and a combination of sunflower-, cottonseed- and groundnut-oilcake meals). These were fed either alone or as a choice with each other or with a low protein food (8·3 g lysine per kg food) to test whether palatability or anti-nutritional factors would override the selection based on protein alone. In both experiments, 10 pigs were housed per pen, with males and females being penned separately. One food bin with a central partition was supplied per pen, and an initial 6-day training period was used, in which pigs experienced each of the two foods on offer, separately, at daily intervals. All pigs were weighed weekly, as was the amount of food consumed in each pen. The conclusions reached were that growing pigs are able to differentiate successfully between two foods on the basis of their amino acid contents, and of changing the selected diet to match their changing requirement for dietary amino acids. However, one of the foods on offer appeared to contain either anti-nutritive factors or unpalatable components, and whereas the piglets performed as well on this as on the other foods of similar nutrient content when these foods were offered as the sole source of food, they actively selected against this food when it was offered as a choice, even if this meant their growing at a significantly slower rate than that of which they were capable.
Hexoestrol implantation of steers fattened at pasture II. Effects on empty weight, carcass weight and carcass quality
Authors: Alder F. E. , Tayler J. C. , Rudman J. E.
Published: September 2010

The first paper of this series (Alder, Tayler and Rudman, 1964) described experiments carried out over 4 years on the effects of hexoestrol on live-weight gain and herbage intake in grazing steers. The 52 steers used weighed between 750 and 1,100 lb. initially and included four pairs of twins. The experiments lasted between 55 and 124 days and involved both summer and winter grazing. This paper is concerned with observations made on the animals after slaughter.
Crossbred sheep production I. Factors affecting production from the crossbred ewe flock
Authors: Yalçin B. C. , Bichard Maurice
Published: September 2010

Donald (1962) has recently pointed out the paucity of available data on production from British sheep, though some information is available for hill sheep (see for example Donald, 1958; Purser and Roberts, 1959; Purser and Young, 1959; Dalton, 1962). Most of these refer mainly to the Scottish Blackface and Welsh Mountain breeds. Hill sheep form approximately 40% of the national flock of over 11 million breeding ewes. Another 40% of ewes are found in crossbred flocks mainly kept on the lowlands; these produce fat lambs and hoggets with wool as a secondary product. Very little information has so far been published on these crossbred ewes, exceptions being work reported by Bywater (1945) and Rennie (1957). This is the first of three papers to be presented with the object of providing such information, and is based mainly on the work of Yalçin (1963). It is hoped that these papers will be of use on two counts:

1. To provide a documentation of one specific cross, the Border Leicester × Cheviot ewe and her Suffolk-cross lambs under North of England grassland conditions.

2. To analyse the usefulness of keeping production records within such flocks as aids to good commercial management, to culling and to selective breeding.

In this paper the traits studied are body weight, fleece weight and litter size of the ewes, and the weights of the lambs between birth and slaughter or weaning. Estimates were obtained for the effects upon some of these traits of age and live-weight of ewe, and of sex, year and type of birth and rearing of the lambs. The usefulness of such correction factors is considered within recording schemes. In subsequent papers the effects on production of differences between crossbred ewes and between the rams used as fat lamb sires will be considered.
Variation in the responses of shorn sheep to cold exposure
Authors: Slee J.
Published: September 2010

Thirteen Blackface and Merino × Cheviot female sheep were shorn and each exposed for a maximum of 10 hours to intense cold (—18° C, 4 m.p.h. wind). Individual exposures were terminated earlier if rectal temperatures fell by 4·5° C. In the first year of the experiment (1963) 11 out of 13 of the sheep were in late pregnancy. There were also 12 control sheep, 9 of them pregnant, which were not subjected to cold treatment. In 1964, 12 of the previously treated sheep were subjected again to similar cold exposures. This time they were unmated and there were no controls.

The cold treatment apparently caused increased variation in gestation length, but the effects on neo-natal lamb mortality were inconclusive.

In 1963 and 1964 there was wide variation between individual sheep in cold tolerance—defined as the ability to maintain rectal temperature during cold exposure. Repeatability for this character was approximately 0·73, suggesting the existence of a genetic component. The average decline in rectal temperature was similar in both years: 3·9·2° C. in 1964. Pregnancy and breed had no detectable effects on cold tolerance.

Skin temperatures on the midside, ear and hind foot (pastern) were measured in 1964. They all declined during cold exposure. Midside skin temperatures typically fell to about 10° C., ear temperatures to about 3° C. and foot temperatures to zero. There were temperature fluctuations due to periodic vasodilation on the ears but the feet generally showed sustained vasoconstriction.

Superior cold tolerance tended to be associated with low mean body skin temperatures and a previous history of live-weight gain. It is suggested that subcutaneous fat deposition may be one factor responsible for improving skin insulation and thereby reducing heat loss in shorn sheep, but direct evidence for this was lacking.
A note on the examination of genotypic ratios in domestic animals using incomplete family data
Authors: Cooper D. W.
Published: September 2010

During the last 10 years many genetical polymorphisms have been discovered in blood proteins. The phenotypes within each system have usually been found to be determined by a series of two of more alleles at a single locus and between which there is no dominance. A number of investigations have compared the fitness of heterozygotes and homozygotes at these loci. Apart from examining for possible associations between heterozygosity and traits for which selection is likely, such as production characters in domestic animals, these investigations have taken one of two forms; either family data have been examined for agreement with Mendelian ratios or else the genotypic numbers in a population have been examined for agreement with Hardy-Weinberg expectations.
Sires' own performance as an indication of progeny performance in testing Suffolk rams for growth rate
Authors: Broadbent J. S. , Watson J. H.
Published: September 2010

Comparisons of performance for growth rate were made on 15 Suffolk rams and their 362 Suffolk × Welsh progeny from 2 to 16 weeks of age or to 100 lb. live-weight, whichever was earliest.

The Suffolk rams were reared artificially from 7 days of age.

A high negative correlation was found between growth rate and efficiency of food conversion.

The correlation between the sires' growth rate and the growth rate of their progeny was 0·25. This was increased to 0·46 by limiting the performance test of progeny to the period between 8 to 16 weeks of age.

Heritability estimates increased as animals grew older. An estimate of 0·52 ±0·012 was obtained for the period 8–16 weeks of age.
The effect of different levels of management on the assessment of differences within a variety of chicken
Authors: Oakes M. W.
Published: September 2010

The data relating to twenty single location trials, involving the progeny of seven sires from one variety mated with random females from another, have been analysed to obtain estimates of sire × location (genotype–environment) interaction for egg production, 23- and 64-week body weights and 32-and 45-week egg weights. In no case was a significant interaction found, indicating genetic correlations not significantly different from unity.

The between- and within-sire components of variance have been calculated for each trait on each location separately. The regressions of these components on the mean levels at the locations have been obtained. Though low and non-significant, they tend to support the use of those locations giving maximum expression of a trait for comparisons involving that trait.
A note on some comparisons between the rumen content of barley-fed steers and that of young calves also fed on a high concentrate ration
Authors: Eadie J. Margaret , Hobson P. N. , Mann S. O.
Published: September 2010

In previous work the rumen microbiology of young animals fed on a high carbohydrate ration has been considered and has tended to be fairly consistent (Eadie, Hobson and Mann, 1959; Eadie, 1962). In this note a further controlled experiment on calves weaned on to a 50:50 mixture of roughage/high concentrate mixture and on to the high concentrate alone, is reported. In view of interest in the intensive feeding of cattle on barley these results from young animals are compared with a series of observations made more recently on older animals fed predominantly on barley, since it was obvious from the outset that the physical nature of the rumen contents was different in the two age groups. The sudden introduction of large amounts of carbohydrate into the diet of animals previously fed conventionally has been shown to create profound changes in the rumen microbial population (Krogh, 1961) and the microbiology of the young concentrate-fed calf was very different from the roughage-fed animal. However, the barley-fed steers used in this work had been early weaned on to a high concentrate ration and had clearly become adapted to the adult high carbohydrate diet.
The relationship between live-weight and herbage intake in grazing cattle
Authors: Hodgson J. , Wilkinson J. M.
Published: September 2010

Six dry cows, six in-calf heifers and six yearling calves grazed in groups of six, arranged either in single age groups or mixed age groups; the arrangements alternated, and each was repeated three times in a continuous grazing sequence with six-day periods. All the animals grazed together for a preliminary period of seven days. Under each arrangement the cattle grazed on a mature sward for two periods, and on an aftermath for one period. Access to fresh and grazed herbage was restricted by electric fences which were moved daily, but the amount of fresh herbage offered was well in excess of appetite at all times.

Records of live-weight, herbage intake, grazing behaviour and social dominance ranking were obtained for all individuals. There was a close relationship between live-weight (LW) and herbage organic matter intake (OMI) in each grazing period, and the regression equations for the six periods were very similar. The best-fit exponent of LW for the pooled results was 0·61±0·038; this was significantly different from 0·73 and 1·0. The exponent increased to 0·71±0·045 when the cow data were excluded. The inclusion of weight change as a third variable was only of value in the mature sward.

The calves ate significantly more, and the cows tended to eat more, when grazing in mixed age groups. These differences could not be explained by differences in the time spent grazing.

There were high simple correlations between LW and OMI, between social dominance rank and OMI, and between LW and rank, particularly in the mixed age groups. When variations in LW were excluded, dominance rank had little influence on OMI in the mixed age groups, but the independent effects of LW and social rank on OMI were of approximately equal importance in the single age groups.
A note on the utilization of urea nitrogen by sheep
Authors: Deif H. I. , Akkada A. R. Abou , El-Shazly K.
Published: September 2010

The effects of giving starch and sulphur, and of the frequency of administration of urea, were measured in N balance experiments with two Rahmany rams. Urea N utilization was greatly improved by dividing a single daily dose into three equal parts. Starch and sulphur also improved the utilization of urea N.
A note on the voluntary food consumption and the sodium-potassium ratio of sheep after shearing
Authors: Ternouth J. H. , Beattie A. W.
Published: September 2010

The daily voluntary food consumption (VFC), water intake and urinary excretion of water, sodium and potassium of eight sheep were studied before and after shearing. The extracellular volume of each sheep was measured twice before and three times after shearing. VFC was significantly higher for the first 3 weeks after shearing than for the 3 weeks immediately before shearing. There was a decreased excretion of Na in the urine and a smaller Na/K ratio for the first 2 weeks after shearing, although the extracellular volume was not significantly increased until 4 weeks after shearing. Within, but not between, the 3-week periods before and after shearing, there was a close linear relationship between VFC and water intake, the latter being significantly less for the same VFC after shearing. During weeks 4 and 5 after shearing, there was an increased loss of Na in the urine and a higher Na/K ratio, and the linear relationship between VFC and water intake was intermediate between that shown before and after shearing. The VFC of the sheep before shearing and in week 5 after shearing were similar.
The effect of level of environment on sex differences in pre-weaning growth rate in beef cattle
Authors: Hopkins I. R.
Published: September 2010

Using pre-weaning records of 3822 calves from 11 Victorian herds, mean male and female growth rates and corresponding sex differences were calculated for each dam age and herd-year class. From these means simple regression equations relating sex differences and growth rates were calculated. There was a close similarity between equations based on dam age means and those based on herd-year means while correlations between sex differences and male growth rates were high.

These results showed that sex differences and female growth rates could be predicted reliably from the level of environment as measured by male growth rate. Sex differences predicted by these regression relationships differed markedly from those predicted by the simple multiplicative and simple additive models generally used in adjusting for sex differences in selection.

The results also suggested that other differences such as breed differences may be predictable in the same way and that such differences are determined primarily by the level of environment per se rather than differences in the nature of the components contributing to that level.
The effect of density on the intake of dried forage pellets by young ruminants
Authors: Tetlow R. M. , Wilkins R. J.
Published: September 2010

Dried grass pellets of high density (1·3 g/ml) were fed ad libitum to British Friesian male calves 5 to 7 mo old (Experiment 1) or 2 to 5 mo old (Experiment 2). All eight animals in Experiment 1 and eight out of 12 in Experiment 2 were fitted with rumen fistulae. In some subperiods of both experiments, pellets were broken down in water and administered as a slurry directly into the rumen at a level equivalent to approximately one-third that of voluntary intake. Intake per os was significantly reduced by this treatment but total intake (per os+per rumen) was not affected.

In Experiment 3 pellets of high (1·24 g/ml) or medium (1·14 g/ml) density were fed ad libitum to 40 9-mo-old Suffolk × Scottish Halfbred wether sheep, either alone or with access limited to 3 hr a day, in which case chopped hay was always available. Pellet density did not affect total intake, but when offered as supplements to hay the consumption of medium-density pellets was higher than that of high-density pellets. In all three experiments animals required 2 or 3 weeks to reach maximum intake of pellets. Over the 42 days of Experiment 3 the proportion of pellets in the feed consumed by animals given pellets as supplements to hay increased from 60 to 80%.
Effects of rumen stimulatory licks on reproductive performance and live-weight gain of beef cattle in Botswana
Authors: Capper B. S. , Pratchett D. , Rennie T. W. , Light D. , Rutherford A. , Miller M. , Buck N. G. , Trail J. C. M.
Published: September 2010

The effects of supplementary feeding of licks containing non-protein nitrogen on the reproductive performance of beef breeding cows and on the live-weight gain of growing stock in Botswana is described. The trials involved 1375 breeding cows at five artificial insemination centres, and 360 breeding cows and 269 growing stock under ranch conditions. These licks increased the percentage of pregnancies in cows under lactation stress by up to 20%, but had no effect on the reproductive performance of dry cows or cows with a calf older than 5 mo. In growing animals the provision of rumen stimulatory licks increased live-weight gain by an average of 12%, but was of doubtful economic value.
Effects of divergent selection for body weight on bone length and diameter in mice
Authors: Hooper A. C. B.
Published: September 2010

The length and diameter of the humerus, ulna, femur and tibia were studied at generations 10 and 14 in lines of mice selected for high and low body weight at 10 weeks of age.

Although some deviations from control were not significant, a general pattern of correlated responses was evident. The divergences of high and low line means for bone length and diameter were significant in the four bones, confirming the contribution of these parameters to genetically determined alterations in body weight. Maternal effects did not affect bone length and diameter and heterosis was not important in the genetic control of these parameters. Unlike bone length, bone diameter continued to diverge in response to the additional four generations of selection. There may therefore be differences in the quantitative genetic control of bone length and diameter and consequently in the control of endochondral and intramembranous ossification.
Reproductive performance of group-synchronized Merino d'Arles and Romanov crossbred ewes. 1. A note on the effects of lactation on fecundity
Authors: Galindez F. J. , Prud'hon M. , Reboul G.
Published: September 2010

Fifty-six Merino d'Aries and 56 Romanov × Merino crossbred lactating ewes were divided into two treatment groups, one (T1) with a ewe-to-ram ratio of 48: 1 (24 Merino and 24 crossbred) and the other (T2) of 64: 1 (32 Merino and 32 crossbred).

Intravaginal sponges with 40 mg FGA (Searle) were inserted in two subgroups at 8-day intervals and withdrawn after 12 and 16 days in situ, in four equal groups at 4-day intervals. A dose of 400 IU pregnant mare's serum gonadotrophin (PMSG) was applied at sponge withdrawal.

Fertility after two oestrous cycles was equally satisfactory in both treatments, though it was lower in treatment group T2. This could be due to the significantly low (P<0·01) number of Merino ewes raddled by the T2 ram (0·33 Merino against 0·92 crossbred) suggesting preferential behaviour by the ram in this treatment.

Comparisons between breeds show a slight superiority in the fertility of crossbred ewes and a highly significant superiority in prolificacy These results suggest that using the described method, 2% of rams seems more than adequate to mate with progestagen-synchronized ewes with a satisfactory fertility level. It is, however, recommended to use homogeneous groups of ewes.
The effect of protein content on the response of lactating cows to level of concentrate feeding
Authors: Gordon F. J.
Published: September 2010

Seventy-two lactating dairy cows were used in a 4x 3 factorial experiment to assess the effects of the protein content of concentrates on the response to concentrate feeding level. Concentrates containing 12,18 and 24% crude protein in the dry matter were given at each of four levels of feeding: 0·25, 0·36, 0·47 and 0·58 kg/kg milk for a 7-week experimental period. Milk yield, milk energy output, liveweight change and the percentage solids-not-fat and protein in the milk were significantly affected by both the level of concentrate feeding and the protein content of the concentrate. Response curves for the effect of level of concentrate feeding on milk output and liveweight change were computed for each of the three protein levels, and although there was no significant interaction between these two main factors the benefit from increased protein in the concentrate was shown to depend partly on the level of feeding at which the concentrate was used. At low feeding levels the response to an increase in protein content of the concentrate tended to be smaller than that obtained at high feeding levels. At no stage was there any marked response to protein content in the concentrate above 18%. The response curves have been used to demonstrate the interchangeability of level of concentrate feeding and protein content of the concentrate as means of supporting a given level of milk production.
The utilization of dried forage crops by growing ruminants
Authors: Owers M. J. , Swan H. , Wilton B.
Published: September 2010

Mixtures (1: 1) of whole-crop dried wheat or barley, with peas or beans as a nitrogen supplement, were fed ad libitum to four groups of 16 6-mo-old male castrate sheep for a period of 42 days in 1971. The mean dry-matter consumptions (kg/day) and live-weight gains (g/day) were: wheat+peas 1·69, 264; wheat+beans 2·05, 288; barley+peas 1·80, 282; and barley+beans 1·81, 229. This experiment was repeated in 1972. The differences between treatments were non-significant.

Dried pelleted whole-crop maize was fed ad libitum to British Friesian steers for 90 days, in conjunction with molasses and one of three protein sources, soya bean meal, urea or whole crop beans. The dry-matter intakes (kg/day) and live-weight gains (kg) were: maize+soya 9·68, 1·26; maize+urea 9·38, 10·4; and maize+beans 9·72, 1·15.

Dried maize in conjunction with urea, whole crop beans and dried grass to supply crude protein levels between 9 and 11% was fed to 48 Hereford × British Friesian steers. The dry-matter intakes (kg/day) and live-weight gains (kg/day) were: whole crop maize, 8·35, 0·87; whole crop maize+urea, 9·55, 1·0; whole crop maize+whole crop beans, 7·44, 0·70; whole crop maize+dried grass, 8·94, 1·15; whole crop maize+rolled barley, 9·30, 1·23; and dried grass + rolled barley, 9·24, 1·21. Although there was no significant difference in live-weight gain between the treatments, two levels of performance were apparent.
A note on purebred performance of Belgian Piétrain pigs
Authors: Howard A. N. , Smith W. C.
Published: September 2010

In an analysis of data from 211 litters in a Pietrain herd, litter size at birth and at weaning was lower than is generally found in indigenous breeds. Mortality in growing and breeding pigs was high with circulatory failure accounting for 23% and 95% of deaths respectively. Pietrains, fed ad libitum over the live-weight range 27 to 87 kg, grew more slowly by 130 g/day than contemporary Large Whites on the same feeding regime, had higher killing-out percentages (by 3 to 4 units) and larger eye muscles in cross-section (by 9·9 cm2) but tended to have higher feed conversion ratios. There was no breed difference in backfat measurements but Pietrain carcasses were shorter by 83 mm and their muscle quality was markedly inferior to that of the Large Whites.
Halothane sensitivity as a field test for stress-susceptibility in the pig
Authors: Webb A. J. , Jordan C. H. C.
Published: September 2010

The possible use of a pig's reaction to the anaesthetic halothane as a field test for Porcine Stress Syndrome in genetic improvement pro-grammes was investigated. A standard 3-min halothane test gave incidences of positive reaction of 20% in a composite Pietrain/Hampshire line, 5% in Norwegian Landrace, 1% in Hampshires and zero in Durocs, Large Whites and N. American Yorkshires. In the Pietrain/Hampshire population, two generations oftwo-way selection on the test gave a divergence in incidence of positive reaction of 85%, and the frequencies of affected progeny supported the hypothesis of monogenic recessive inheritance. From second tests made 20 days after the first, the probability of misclassifying a pig's reaction on one test was 5 ± 1%. Positive reactors had significantly shorter and leaner carcasses, fewer pigs born alive, poorer meat quality, higher mortality and greater plasma creatine phosphokinase activity than negative reactors.
Annual reproductive rhythm and ovulation rate in four fat-tailed sheep breeds
Authors: Sefidbakht N. , Mostafavi M. S. , Farid A.
Published: September 2010

Karakul, Mehraban, Naeini and Bakhtiari sheep were checked twice a day for oestrus using aproned rams and were laparotomized within 5 to 16 h of the end of every second oestrous period. Oestrus was observed for 12 monthly periods commencing on 21 April.

The Mehraban breed with 1 -6 oestrous periods per month was less seasonal in its breeding activity (P<0·01) than the other breeds. Four-year-old ewes were more sexually active (P<0·01) than 3-year-old ewes (1·48 v. 1·28 oestrous periods per month). Seasonal variation in the sexual activity of the ewes was observed (P<001); the peak of activity in July to January was followed by a steady decline in February and March to a low in April and May, and then a steep recovery phase in June. There was only limited sexual activity for at least 4 months (March to June).

The overall mean cycle length was 17·8 days (14 to 23 days), and the means for the four breeds were 17·6, 17·8, 17·8 and 17·9. The oestrous cycle was longer (P<0·05) during the period from December t o February than during that from June to August.

The overall mean duration of the oestrous period was 36·9 h and the means for the four breeds were 35·2, 38·0, 37·4 and 37·1 h, respectively (P<0·05). The duration showed some monthly variation (P<0·01) but did not follow a special seasonal pattern. The ovulation rates for the four breeds were 1·07, 1·13,0·94 and 0·95 respectively, (P<0·01). There was a non-significant decline in the mean ovulation rate from March to June. Right ovaries were more active than left ovaries as judged by the observation of a higher average number of corpora lutea per ewe per laparotomy (0·58 v. 0·43, P<001).
Pre- and postnatal study of the carcass growth of sheep 1. Growth of dissectable fat and its chemical components
Authors: Broad T. E. , Davies A. S.
Published: September 2010

Twenty-four prenatal (15 female), and 15 postnatal female Romney sheep, comprising a weight range from 3g to 60 kg, were dissected into their major carcass tissues. Adipose tissue was not dissectable from foetuses aged less than 80 days. The growth rates of the dissected adipose tissues and their chemical components, deoxyribonucleic acid, protein, and total lipid subdivided into phospholipid, cholesterol and triglyceride, were compared relative to the growth of the total carcass wet weight. Total side (half-carcass) adipose tissue grew at a rate substantially greater than total carcass weight. The subcutaneous adipose tissue of the forequarter grew at the fastest rate while that from the shoulder, sternum and internal cavity of the forequarter grew slowest, at rates which were not significantly different from that of the carcass. Of the chemical components, triglyceride and cholesterol grew at the fastest rate, deoxyribonucleic acid grew at the slowest rate, and phospholipid and protein grew at intermediate rates; all grew faster than the carcass. Predictions were made of the distribution of triglyceride in the carcass of the sheep at different stages of growth.
A note on the storage of sodium hydroxide-treated whole-crop barley beneath grass and lucerne silage
Authors: Moore A. , Harris C.
Published: September 2010

One hundred tonnes of spring-sown barley harvested as whole crop were treated on a commercial farm with pearl sodium hydroxide at 46 g/kg dry matter.

The treated material was stored in a silage clamp beneath grass and lucerne silage. A thin layer of grass, cut and wilted to hay-making dry matter, was placed immediately on top of the barley to absorb any silage effluent.

Monthly samples were taken for microbiological examination and chemical analysis throughout winter storage, while the material was fed to British Friesian dairy cows. There was no evidence of fermentation by clostridia in the whole-crop barley or wilted grass and there was no spoilage of the exposed feeding face. The treatment increased the in vitro organic matter digestibility and the in vitro digestible organic matter in the dry matter of the whole-crop barley. No excessive urination or other ill effects were observed in the stock.

The method proved practical for the satisfactory storage and feeding of sodium hydroxide-treated whole-crop barley.
A note on the influence of Avoparcin on apparent digestibility and nitrogen retention in growing pigs
Authors: Ellis M. , Davies M. , Briggs P. A. , Armstrong D. G.
Published: September 2010

A metabolism trial was carried out to examine the influence of an antibiotic food additive (Avoparcin) on the apparent digestibility of nutrients and nitrogen retention in the growing pig. Two groups of pigs, comprising 12 castrates per group, were fed a barley-based diet (190g crude protein per kg dry matter) with or without the inclusion of the antibiotic (at a dietary concentration of 20 mg/kg). Addition of Avoparcin had no significant effect on the apparent digestibility of dry matter or gross energy but resulted in a small increase in the apparent digestibility of nitrogen (0·012; P < 0·05). There was a corresponding improvement in nitrogen retention (0·051) but the difference was not statistically significant.
Effects of sex and energy intake between 48 and 90 kg live weight on protein deposition in growing pigs
Authors: Campbell R. G. , Taverner M. R. , Curic D. M.
Published: September 2010

Twenty four entire male and 24 female pigs growing from 48 to 90 kg live weight were used to investigate the effects of five rates of food intake supplying daily between 23 MJ digestible energy (DE) and 41·8 or 39·2 MJ DE for entire males and females respectively, on rate of protein deposition, and on growth and body composition.

Entire males deposited protein faster than females, and for both sexes the rate of protein deposition increased linearly with increase in energy intake up to 33 MJ DE per day (P < 0·001) but was not significantly affected by further increase in energy intake.

Average daily gain increased quadratically (P < 0·001) with increase in energy intake and at all levels was higher for entire males than for females. Food:gain ratio (g food per g growth) which was lower for entire males improved with increase in energy intake up to 33 MJ DE per day and deteriorated with further increase in energy intake.

At 90 kg live weight entire males contained less fat and more protein and water in the empty body than females. For both sexes, body fat content increased at a decreasing rate with increase in energy intake up to 33 MJ DE per day, and at an increasing rate with further increase in energy intake.

Total energy retained was linearly (P < 0·001) related to energy intake and at all rates of energy intake was higher for females than for entire males. The estimates of DE required for maintenance were 15·9 MJ/day (0·664 MJ/kg M0·75 per day) and 12·4 MJ/day (0·51 MJ/kg M0·75 per day) for entire males and females, respectively.
Citric acid and fumaric acid as food additives for early-weaned piglets
Authors: Henry R. W. , Pickard D. W. , Hughes P. E.
Published: September 2010

The effects of diet acidification on the growth performance of piglets were assessed in two experiments. In the first, 167 piglets were weaned at 10 days of age and penned in litter-mate groups (seven groups per treatment) which were allocated to one of three diets, with either citric acid (30 g/kg; C), fumaric acid (15 g/kg; F) or no additional organic acid (N); pigs were fed ad libitum for 25 days. The rate of live-weight gain was significantly higher for treatment C than for treatments F or N (216 (s.e. 10), 170 (s.e. 7) and 189 (s.e. 6) g/day respectively; P < 0·05). The voluntary food intake on treatment C also tended to be higher than on the other two diets (220 (s.e. 24), 182 (s.e. 18) and 189 (s.e. 7) g/day for treatments C, F and N respectively).

In experiment 2, 30 crossbred piglets were penned in single-sex groups of three and weaned at 10 days of age. The same diets were used as in experiment 1 but all three diets were available ad libitum to each group of piglets for 25 days. When dietary choice was allowed, piglets consumed significantly greater quantities of the control diet than of the acidified diets (1381, 1422, 2972 (s.e. 132) g/day for diets C, F and N respectively; P < 0·01). When the relative intake of each diet was correlated with live-weight gain, only diet C showed a significant positive correlation (r = +0·74; P < 0·05). Correlations of F and N intakes with live-weight gain were negative. It is concluded that citric acid (30 g/kg) in the diet of early-weaned piglets promotes live-weight gain, although acidification of the diet may decrease palatability.