bluuebunny/crossref_metadata_2025 huggingface dataset:
Environmental and genetic causes of variation in production traits of Damascus goats. 2. Goat productivity
Authors: Mavrogenis A. P. , Constantinou A. , Louca A.
Published: September 2010

Data on 1474 lactation records obtained from 1972 to 1978 were used to study environmental and genetic influences on production characters in the Damascus goat. Year and month of kidding had a significant effect on 90- and 150-day milk production after weaning, lactation length and litter weight at weaning (P < 0·01), but no influence on litter weight at birth. Milk production after weaning was not related to litter weight at birth or at weaning. Age of goat at kidding had a significant quadratic effect on milk production, and litter weight at birth and at weaning. No such effects were found for lactation length.

Estimates of heritability, from paternal half-sib correlations, for 90- and 150-day milk production were similar (0·29 (s.e. 0·14)). The genetic correlation between 90- and 150-day milk yield (0·92 (s.e. 0·03)) was high, indicating that part and whole lactation yields are influenced by the same genes. The phenotypic correlations among milk yield traits and lactation length were also high and positive.
A note on sodium bentonite as an additive to grower pig diets
Authors: Taverner M. R. , Campbell R. G. , Biden R. S.
Published: September 2010

In pigs growing from 20 to 70 kg live weight, the addition of 40 g sodium bentonite to each kg diet was without significant effect on growth performance under ad libitum and restricted feeding regimes. Sodium bentonite appeared to be indigestible and inert, as dry-matter digestibilities were reduced from 0·87 to 0·85 and 0·83 by the addition of 20 and 40 g sodium bentonite per kg diet respectively.
An integration of mathematical models for feeding and lactation with reproductive performance of the dairy cow
Authors: Goodall E. A. , McMurray C. H.
Published: September 2010

A mathematical model based on the energy requirements of the dairy cow and the lactation model of Wood was constructed to determine the effect on net returns over concentrates of different calving intervals for different weeks of the year under different feeding management conditions. The model was computerized, and this enabled an investigation of the effect on net returns of varying silage metabolizable energy levels and different nutritional management systems. The importance of the modelling approach in examining a range of interacting factors simultaneously is highlighted. To illustrate this approach, results are presented here with 1981 prices for milk, concentrates and calves kept constant over a period of 4 years and also, to validate this approach, using actual prices paid over the period 1976 to 1981.
A comparison of Canadian Holstein × British Friesian and British Friesian steers for beef production. 2. Carcass characteristics
Authors: Baber P. L. , Rowlinson P. , Willis M. B. , Chalmers A. J.
Published: September 2010

A comparison was undertaken of 85 Holstein × Friesian (HF) and 84 Friesian (F) steer carcasses that had been produced on three production systems. These were: intensive barley beef (BB); grass/cereal 18 month; and 24 month forage system. On each system, HF steers were heavier at slaughter (over all systems, 476·5 v. 453·3 kg ***) and had a lower killing-out proportion (512 v. 521 g/kg ***), which resulted in higher carcass weights (243·5 v. 235·9 kg **). Steers were slaughtered on reaching a standard degree of finish (equivalent to European Economic Community fat-class 3), provided that they had attained a minimum live weight. There were no significant differences in carcass fat class (3·23 v. 3·35) but HF had poorer carcass conformation classification (2·62 v. 3·21 ***). Of the HF carcasses, 60·4% were rejected on conformation for Beef Premium Scheme payments and only 29·0% of the F carcasses were rejected (P < 0·001): a considerable and unmerited financial penalty. Objective carcass measurements showed HF to have longer sides (1257 v. 1233 mm ***), longer legs (812 v. 790 mm ***) and deeper forequarters (420 v. 402 mm ***). These differences remained when dressed carcass weight and sample-joint fat proportion were taken as covariates. Comparison of the weight-adjusted carcasses showed the HF to have reduced rump (P < 0·001) and loin thickness (P < 0·05). No other consistent effects were seen for carcass measurements, subjective scores or colour attributes. Dissection of the 7th t o 9th rib joint, as a predictor of carcass composition, revealed no significant overall differences in proportions (g/kg) of muscle (571 v. 567), bone (219 v. 219) or fat (206 v. 212). The implications of carcass value of the above findings are discussed.
Effects of the dietary inclusion of copper sulphate, avoparcin and carbadox/sulphadimidine supplements on the performance of pigs weaned at 25 days
Authors: Patterson D. C.
Published: September 2010

Two experiments, involving 144 and 168 pigs weaned at 22 to 31 days, to investigate the response to inclusion of copper (CuSO4.5H2O), copper plus carbadox/sulphadimidine or copper plus avoparcin supplements in starter and grower diets were made. The carbadox and sulphadimidine levels were 50 and 100 mg/kg diet respectively in both diets. Avoparcin was included at 40 mg/kg in the starter diets and 20 mg/kg in the grower diets. In the first experiment the levels of copper were either 180 or 340 mg/kg in the starter diets and either 90 or 270 mg/kg in the grower diets. In the second experiment the levels were either 20 or 180 mg/kg in the starter diets and either 10 or 180 mg/kg in the grower diets.

In the starter period of the first experiment, supplementation with carbadox/sulphadimidine or avoparcin proportionately increased the rate of growth by 0·41 and 0·07 respectively in relation to supplementation with 340 mg copper per kg diet (P < 0·05). Neither supplement improved growth rate in the grower period. In the second experiment there were no significant differences in growth rate. However the rates of growth in both the starter and grower periods were higher in pigs receiving carbadox/sulphadimidine than in those receiving avoparcin, while these in turn grew slightly faster than those receiving copper only.

Taking into account the costs of the supplements the inclusion of the carbadox/sulphadimidine supplement produced an economic benefit compared with the other treatments.
A note on the accuracy of the New Zealand Hennessy Grading Probe and the Danish Fat-O-Meater in measuring fat and muscle thickness in pig carcasses
Authors: Fortin A. , Jones S. D. M. , Haworth C. R.
Published: September 2010

Two hundred and twenty-four pig carcasses were used to compare the Hennessy Grading Probe and the Fat-O-Meater in their accuracy for measuring fat and muscle thickness (m. longissimus). Accuracy was defined in terms of precision and bias. The precision (relationship between repeated measurements) of the two probes in measuring fat and muscle thickness varied with the probing locations. When differences were detected, the higher precision was found with the Fat-O-Meater. The mean bias in measuring fat thickness was negative for the Hennessy Grading Probe (P< 0·01); however, for the Fat-O-Meater, no mean bias was detected. Furthermore, the extent and the direction of the bias in measuring fat over the range of fat thickness studied varied with the probe and the probing location.
A note on the effects of variations in food intake on nitrogen retention in control and selection lines of Large White pigs
Authors: Henderson Ruth , Whittemore C. T. , Ellis M. , Smith W. C. , Laird R.
Published: September 2010

Fifty-three 7-day nitrogen balances were made using 13 control (C) and 15 selection line (S) Large White boars. Six feeding treatments were imposed, ranging from a Jevel estimated to maintain weight to a level aimed at inducing a fast growth rate from giving food twice daily to appetite for 30 min. Nitrogen retention did not differ significantly, but C boars retained slightly more than S boars at the lowest food intake, while S boars retained Slightly more than C boars at higher food intakes. The slopes of the regression of nitrogen retention against food intake for growth was steeper for S than for C boars (P > 0·05). It is concluded that great care should be taken in using metabolism experiment results to predict changes in body composition.
Effects of Zeranol® implants and dietary supplement on growth rate, endocrine status and blood metabolite levels of growing lambs at pasture
Authors: Rhind S. M. , Zygoyiannis D. , Doney J. M. , Leslie I. D. , Hart I. C.
Published: September 2010

In a 2 × 2 factorial experiment, the effect of implants of the growth promoter Zeranol, with and without supplementary food, on the growth rate, blood metabolite and hormone profiles of lambs finished at pasture was examined. For lambs fed no supplement, Zeranol implants increased growth rates from 166 to 185 g/day (s.e. of difference = 11·4) whereas for animals fed supplement the response to Zeranol was much greater, the growth rates being 167 and 234 g/day (s.e. of difference = 12·8). Supplement given to lambs not treated with Zeranol replaced a proportion of the herbage intake while, in lambs given supplement and treated with Zeranol, herbage intake was greatly increased (P< 0·001). Plasma glucose and urea concentrations were not affected by treatment but non-esterified fatty acids (NEFA) were depressed and albumin levels increased by Zeranol implants, while supplementary food caused reductions in plasma NEFA and urea concentrations. It is suggested that Zeranol treatment and supplementary food acted synergistically through changes in insulin and growth hormone concentrations to induce a much larger increase in growth rate in the treated animals given supplementary food than in those given either Zeranol or supplement alone. The response to Zeranol may also have been altered by differences in thyroid hormone status associated with supplementary food.
Effect of nutrient density, presence of fish meal and method of feeding of unmedicated diets on early-weaned pigs
Authors: Pike I. H. , Curran M. K. , Edge M. , Harvey Anne
Published: September 2010

In two experiments, the first with 96 pigs from 5 weeks of age and the second with 384 pigs from 3 weeks of age, high nutrient dense diets (HND) or conventional diets (CONV) were given with (50 g/kg diet) or without fish meal, up to slaughter at 90 kg live weight. Diets were unmedicated. In both experiments pigs were given food according to scales which equalized digestible energy intakes for the HND and the CONV diets. In experiment 1 pigs were individually fed; in experiment 2 group feeding was practised with pens of 16 pigs either floor or trough fed.

There was no mortality in experiment 1, but the mortality was high in experiment 2, particularly amongst those pigs receiving the CONV diet without fish meal. In experiment 1, in the first 56 days, inclusion of fish meal in the CONV and HND diets significantly improved growth rate but food conversion efficiency was significantly improved in the CONV diet only. Overall, up to slaughter, growth rate and food conversion efficiency were significantly poorer in pigs given the CONV diet without fish meal (cf. the three other diets) but the HND diets were significantly better than the CONV diet with fish meal. In experiment 2, overall there were no significant differences in performance between floor- and trough- feeding methods, CONV diets without fish meal gave significantly poorer growth rates in the first 56 days and overall than the other three diets, between which there were no significant differences. In both periods, for food conversion efficiency, fish meal inclusion was without significant effect in the HND diets but significantly improved the CONV diets, both of which were significantly inferior to the HND diets.
A note on the occurrence of isolated melanin pigmented fibres in the white fleece wool of Corriedale sheep
Authors: Fleet M. R. , Stafford J. E. , Dolling C. H. S.
Published: September 2010

The occurrence of melanin pigmented wool fibres in the skirted white fleece wool from 1-year-old Corriedale ewes, having either least (group 1), most (group 3) or an intermediate level (group 2) of black nose skin pigmentation, was investigated. Thirteen of the 87 fleeces analysed had the equivalent of 10 to 389 isolated pigmented fibres per 100 g of scoured wool. The mean diameter of the pigmented fibres was similar to that of the fleece specimens analysed and they occurred singly or in small groups within individual staples. Large numbers of isolated pigmented fibres in fleeces were widely distributed, and constitute a serious problem of identification by visual inspection. Fibre darkness and the number of fleeces found with pigmented wool fibres were two measurements which showed a significant association (P < 0·001 and P < 0·05, respectively) with nose skin pigment group. With one exception from group 2 the results support the suggestion that the usual selection for dark nose skin in this breed may be antagonistic to selection for a white fleece. The pigmented lengths of fibres were found to be independent of nose skin pigment group.
Selection for growth in mice on two diets
Authors: Dalton D. C.
Published: September 2010

Mice were selected for high and low growth (i.e. weight gain from 3 to 6 weeks of age), within litters for thirteen generations. This was carried out on a full and on a diluted diet which provided a good and a poor plane of nutrition. A randomly bred control line was maintained on each diet. Responses to selection were obtained in both directions and on both diets, although the diluted diet was subject to an unexplained deterioration. The indirect responses on either plane of nutrition were equal to the direct responses on the same plane. Hence selection for growth could be as well carried out in the environment in which the animal was to perform, as in any other environment. These results were discussed in relation to similar studies and to their practical implications.
The effect of ammonium acetate on the yield and composition of milk from heifers
Authors: Kay M. , Walker T. , McKiddie G.
Published: September 2010

1. Two experiments are described in which the effects of ammonium acetate on the yield and composition of the milk from heifers given (1) a fat-depressing diet consisting mainly of cereals or (2) a normal diet of silage and sugar beet pulp for maintenance and rationed concentrates according to yield.

2. In the first experiment acetate increased the content of butterfat in the milk from 2·76 to 3·12. This difference was almost significant (P < 0·1). There was no significant effect of acetate on the total solids content of the milk.

3. In the second experiment acetate very slightly depressed the total solids and the butterfat content of the milk.

4. In Experiment 1 there was no significant difference between treatments i n the pH of rumen liquor, or in its concentration of total steam volatile fatty acids, but the proportions of acetic and isobutyric acids were higher on the acetate treatment.

5. In Experiment 2 there were no differences in the relative proportions of the fatty acids although the total steam volatile fatty acid concentration was higher on the acetate treatment.
Pre-slaughter social activity of young bulls relating to the occurrence of dark-cutting beef
Authors: Franc C. , Bartoš L. , Hanyš Z. , Tomeš Z.
Published: September 2010

Twenty bulls of three different breeds were tethered individually from 5 months until slaughter at 21 months. On the day of slaughter, the bulls were divided into groups of five animals, transported and then released in a pen. The first bull of the group was slaughtered 60 or 110 min after regrouping. Subsequent bulls were slaughtered individually at 50-min intervals. Social interactions among the bulls were recorded. Muscle pH, light reflectance values and water-holding capacity were measured in samples of m. longissimus dorsi. These characteristics showed correlations with the amount of non-agonistic social activity in which a bull had been involved before slaughter. The characteristics were also correlated with the number of agonistic interactions. Whether a bull was behaving as a dominant or a submissive animal did not influence the incidence of dark-cutting meat as judged by pH values. On the other hand, light reflectance values and water-holding capacity were correlated with the number of passive agonistic interactions (i.e. how many times a bull was attacked) and considerably less with the number of active interactions (number of attacks by the bull). The incidence of butting was not significantly related to muscle characteristics but mounting was significantly correlated with them.

The study indicates that dark-cutting beef is primarily caused by physically exhausting activities such as mounting, and further modified by stress-inducing social interactions.
Reproductive and lactational responses and serum growth hormone and insulin in fine-wool ewes treated with ovine growth hormone
Authors: Holcombe D. W. , Hallford D. M. , Hoefler W. C.
Published: September 2010

Eighteen mature (3 to 6 years) Debouillet × Rambouillet ewes (mean weight 79·2 (s.e. 21) kg) producing and nursing single offspring were randomly allotted to one of three groups to examine the influence of ovine growth hormone (oGH) on reproductive, hormonal and lactational responses of springlambing ewes. Each ewe received a daily subcutaneous injection of either 0, 5 or 10 mg oGH from day 11 through to day 20 post partum (day 0 = parturition). Treatment groups were subdivided into two pens (three ewes per pen) and food intake was monitored from day 1 through to day 20 post partum. On days 11 and 20 post partum, jugular blood samples were collected before and hourly for 8 h after treatment. Blood samples were also collected daily from day 10 through to day 21 post partum and on alternate days through to day 40 post partum. Milk production (oxytocin-induced hand milking) and fat and protein concentrations were determined 21 days post partum. Food intake did not differ before or during the treatment period (P > 0·05). Likewise, ewe and lamb weights were similar among treatment groups through to day 60 post partum (P > 0·05). Serum insulin did not differ before or after treatment on day 11 (P > 0·05); however, on day 20 before treatment, serum insulin was significantly higher in ewes receiving 5 (2·3 (s.e. 0·3) μg/I) and 10 (2·4 (s.e. 0·3) μg/1) mg oGH than in controls (1·2 (s.e. 0·3) μg/1) (P < 0·05). After treatment, no differences were detected in serum insulin among treatments on day 20 post partum (P > 0·05). Serum growth hormone (GH) was similar among groups before treatment on day 11 post partum; but by 8 h after treatment, serum GH was significantly elevated in ewes receiving 10 mg oGH (32·4 (s.e. 1·9) μg/1) compared with ewes receiving 5 (13·9 (s.e. 1·9) μg/1) or 0 (4·5 (s.e. 1·9) μg/1) mg oGH (P < 0·01). By 20 days after lambing, serum GH differed significantly among groups both before and after administration of exogenous oGH (P < 0·01). Ewes receiving 5 or 10 mg oGH produced 2·3 (s.e. 0·2) kg milk per day compared with 1·9 (s.e. 0·2) kg/day for controls (P < 0·10). Milk fat and protein concentrations did not differ significantly among treatments (P > 0·05), but total fat yield was higher in ewes receiving either dose of oGH (206 (s.e. 20) g/day) compared with control ewes (141 (s.e. 20) g/day) (P < 005). Serum progesterone remained less than 0·5 μg/1 in ewes through to day 40 post partum. A linear decrease was observed in interval from parturition to first observed oestrus as dosage of oGH increased (116, 108 and 102 (s.e. 6) days for ewes receiving 0, 5 and 10 mg oGH, respectively; P = 0·10). Administration of exogenous oGH to lactating. anoestrous ewes between days 11 and 20 post partum enhances milk production and may influence the interval to oestrus.
Growth and carcass characteristics of desert goat kids and their temperate cross
Authors: Bello A. , Babiker S. A.
Published: September 2010

Crossbreeding of desert goat does with the temperate Saanen x Toggenburg buck was found to result in a significant increase in the daily live-weight gain and the empty body weight of their progeny slaughtered at about 30 kg live weight when compared with purebred desert goat kids (P < 0·001). Food intake did not differ between the two types of kids, but live-weight food conversion efficiency was significantly superior in crossbred kids (P < 0·05).

Carcass weight and killing-out proportion tended to be greater in the crossbred kids reflecting lower weights of head, skin, internal organs and gut fill. Breed types did not differ in the weights of individual wholesale cuts. Carcass dissection revealed significantly higher muscle proportion (P < 0·05), significantly lower fat proportion (P < 0·01) and higher muscle: bone ratio in the crossbred kids.
A comparison of inbred and outbred sheep on two planes of nutrition. 3. A note on the effects on semen characteristics before and after exposures to acute cold and heat
Authors: Wiener G. , Woolliams Carol , Slee J.
Published: September 2010

Traits associated with fitness such as aspects of reproduction (for a review see Lamberson and Thomas, 1984) and lamb survival (Wiener, Woolliams and Macleod, 1983) are seriously affected by inbreeding. Homeostatic control is an important component of fitness in animals. In an experiment reported by Wiener, Woolliams and Slee (1988) and Slee, Wiener and Woolliams (1988), inbred (I) rams were far less able to resist acute cold than outbred (O) rams. The opportunity was taken in this same experiment to examine the effects of inbreeding, plane of nutrition (high (H) or low (L)) and exposures to acute cold and heat on aspects of semen quality.
A comparison of undried and dried fish-protein hydrolysate as a protein source for calf milk replacers
Authors: Petchey A. M. , Owen J. B. , Mackie I. M. , Ritchie A. H. , Ørskov E. R.
Published: September 2010

Milk replacers in which skim milk protein (SMP) was replaced in various proportions by undried or dried fish protein hydrolysate (FPH) were offered twice daily to British Friesian male calves. Various proportions of fish protein and milk protein in the diets were obtained by mixing replacer made from SMP with replacers made from undried and dried FPH respectively. The ratios were: 100 FPH, 0 SMP; 67 FPH, 33 SMP; 33 FPH, 67 SMP; and 0 FPH, 100 SMP. Calves were offered the milk replacers only to a maximum of 5 1 per day until 28 days when concentrates and hay were offered ad libitum. The calves were weaned after 42 days. Feed intake and live-weight gain were recorded for 84 days.

There was a marked decrease in performance to weaning when the milk replacer contained two-thirds or more of the FPH. The FPH-fed calves had lower hay intakes than those fed milk only. Treatment differences in post-weaning live-weight gain reflected mainly differences in concentrate intake. There was no significant difference in live-weight gain nor food efficiency for calves fed either undried or dried FPH in any period to 84 days. The number of treatments for scour was similar for the two groups. However, the calves fed dried FPH had a lower dry-matter intake in the post-weaning period.
The effects of body weight and its components on lambing performance in some commercial flocks in Britain
Authors: Geisler P. A. , Fenlon J. S.
Published: September 2010

An analysis of the records of ewe weight and condition at mating together with subsequent lambing performance for several commercial flocks in the UK revealed no significant relationship between lambing performance and size, measured by weight transformed to a standard condition. The relationship between mating weight and body condition score at mating was linear though there was considerable variation in weight at a fixed body condition, suggesting a substantial spread in skeletal size. Increases in ovulation rate were not discernible from lambing figures over the range of body conditions observed in these flocks.
Reproductive physiology in the pig with special reference to early weaning
Authors: Polge C.
Published: September 2010

The object of this paper is to review some aspects of reproductive physiology in the pig, especially in relation to conditions after farrowing when reproductive ability is normally inhibited by lactation and suckling, and when weaning at different periods after parturition may have a profound influence on the chances of successful conception and pregnancy. In undertaking this review, however, it soon became clear that very few detailed experimental studies had been carried out in sows during the period immediately following parturition. It was considered best, therefore, to compare some of the situations which exist in pigs at other reproductive stages with what little is known about the sow at the post partum stage and during lactation.
Metabolic diseases
Authors: Todd J. R.
Published: September 2010

The most important metabolic disease associated with intensive grassland production and utilization in Northern Ireland is grass tetany. Grass tetany or hypomagnesaemic tetany was recognized in the early decades of this century in Europe and probably appeared in the British Isles in the early 1920's. There has been a steady increase in incidence over the years, and this would seem to be related to an increase in productivity, both in terms of output from the animal and from pasture.
Anatomical aspects of growth
Authors: Butterfield R. M. , Berg R. T.
Published: September 2010

Under this very broad title we have selected three aspects of current and recent work which have a bearing on our understanding of the interpretation of findings dealing with muscle-weight distribution. The first is a justification of the anatomical approach, the second a confirmation of, and elaboration on, some earlier work, and the third a suggestion for some future thinking.
Body size and efficiency
Authors: Robertson Alan
Published: September 2010

One of Bertrand Russell's contributions to philosophy was to show that there are certain questions, quite simple to state, to which no sensible answer can be given. While writing this paper I began to feel that the question ‘what is the optimum size of the dairy cow ?’ is perhaps among these. Let me first ask what we mean by the question, what assumptions we have to make to answer it, and finally what use is the answer.
Genetic differences in milk production in relation to mature body weight
Authors: Taylor C. S.
Published: September 2010

A survey of the accumulated experimental evidence suggests that the general effect of genetic differences in body size on input-output relationships in livestock might be largely accounted for by the following two genetic sizescaling rules:

1. treat all age and time variables for the ith genotype as directly proportional to Mi0·27, where Mi is the mature body weight of the ith genotype;

2. at every age standardized as in (1), treat all cumulated inputs and outputs for the zth genotype as directly proportional to Mi.
Operational research techniques and their application to research and development
Authors: Jones P. M. S.
Published: September 2010

The request to deliver this paper called for a presentation on the methodology of research and development (R and D) resource allocation in a form suitable for a lay audience. As a pragmatist who believes that tools only have a value if they can be used to improve the way in which the job is done, I would very much prefer to be speaking on practical case studies. Nevertheless, I will attempt to stick to the given remit and describe some of the approaches to R and D resource allocation that are available, and to comment on their practical usefulness based on the experiences of myself and my colleagues at the Programmes Analysis Unit.
A multi-disciplinary approach to the development of intensive animal systems for Canada
Authors: Gowe R. S. , Barr G. R. , Peters H. F.
Published: September 2010

It is indeed an honour to be asked to present the 1974 Sir John Hammond Memorial Lecture, and I face this honour with some trepidation knowing the high esteem held for Sir John and his outstanding contributions to world animal science. As most of you know, Sir John was somewhat of a one-man multi-disciplinary team himself, publishing and researching in the fields of animal breeding, reproductive physiology, meat science and animal nutrition. With the rapid and sometimes almost exponential increase in new findings in each of these areas, one person, even one of Sir John Hammond's stature, would now have great difficulty making significant contributions in the several scientific disciplines closely associated with animal production.
Estimation of direct additive and maternal additive genetic effects for weaning weight in Mashona cattle of Zimbabwe using an individual animal model
Authors: Khombe C. T. , Hayes J. F. , Cue R. I. , Wade K. M.
Published: September 2010

Weaning weights (or weight nearest to 205 days of age) from 8086 Mashona calves were collected from seven herds covering the period 1976 to 1988. Estimates of (co)variance components were obtained by restricted maximum likelihood using a derivative free algorithm and fitting an individual animal model. Estimates of direct additive heritability, maternal additive heritability, their correlation, total heritability and repeatability, obtained under two models were 0·243 and 0·281, 0·113 and 0·392, –0·282 and –0·269, 0·252 and 0·298, and 0·409 and 0·573, respectively. Trends within herd were estimated from the mean value of progeny born within a particular year. There were no significant trends in direct additive breeding values. A general decline in maternal breeding values was observed. Only one herd (herd 1) had a significant eroiyonmeYital freni (0·385 kg/year). It IMS emphftsilfiti that any future revision of the method used to improve the weaning weights of beef cattle should also improve their maternal breeding values.
Metabolic responses to hyperinsulinaemia under glucose-potassium-amino acids clamp in lactating and non-lactating goats
Authors: Tauveron I. , Debras E. , Tesseraud S. , Bonnet Y. , Thiéblot Ph. , Champredon C. , Grizard J.
Published: September 2010

The present experiment was undertaken to investigate adaptations to insulin action on metabolism during lactation by using plasma concentrations of β hydroxybutyrate (β OH) free fatty acids (FFA) and lactate (L) as indicators. The study included three groups each of four goats. One group was used at 12 to 31 days post partum (early lactation), one group at 98 to 143 days post partum (mid lactation) and one group at 1 year post partum (dry period). For a given physiological state, each goat was examined four times to study the effect of insulin infused for 2·5 h at two rates, medium (0·36 nmol/min) followed by high (1·79 nmol/min) in two protocols: under normal aminoacidaemia in study 1 followed by hyperaminoacidaemia in study 2. Appropriate amino acid infusions were used to blunt insulin-induced hypoaminoacidaemia under eukaliaemic and euglycaemic clamp conditions or to create hyperaminoacidaemia and maintain this state under insulin treatment. In the basal state βOH (P < 0·05), mid lactation) and FFA (P < 0·05 early lactation) were higher during lactation than in the dry period. Plasma L was unmodified. Insulin infusion always resulted in a decrease in βOH levels (P < 0·05). In both studies, the change in βOH concentration as a function of changes in plasma insulin (an index of insulin sensitivity) was greater during early lactation than in the dry period (P < 0·05); this was also the case of mid lactation in study 1. Insulin infusion decreased plasma FFA during early lactation and in the dry period in study 1 (P < 0·05), and there was a trend for insulin sensitivity to be greater during early lactation. In both studies insulin infusion did not affect plasma L in lactating goats whereas plasma L was increased in dry animals (P < 0·05). The results demonstrate that during early lactation, compared with the dry period, there is an increased ability of insulin to lower βOH and FFA concentrations. These effects were not altered by increasing plasma amino acid concentrations during insulin infusion.
A simulation study of open nucleus and closed nucleus breeding systems in a sheep population
Authors: Roden J. A.
Published: September 2010

Stochastic simulation was used to compare the results of alternative breeding systems in a sheep population divided into 10 flocks of 120 ewes. The breeding systems compared were selection within closed flocks (CF), a closed nucleus system (CNS), an open nucleus system (ONS) and open nucleus systems with the selection of nucleus replacements being restricted to either nucleus born males (ONSRm) or nucleus born females (ONSRf). Selection was for a best linear unbiased prediction of breeding value for lamb live weight which had a heritability of 0·17. The open nucleus breeding systems (ONS, ONSRm, ONSRf) resulted in higher rates of genetic gain, more predictable selection responses and lower rates of inbreeding than either the closed nucleus system (CNS) or selection within closed flocks (CF). Initial genetic differences between flocks resulted in higher rates of genetic gain in the nucleus breeding systems due to the use of between flock genetic variance. In the ONS system up to 25% of nucleus sires and approximately 50% of nucleus dams were born in base flocks. Nevertheless if selection of either nucleus sires or dams was restricted to nucleus born animals there was very little change in genetic gain or rate of inbreeding.
Bromocryptine is effective in reducing milk production in ewes during lactation, but has no additional effect during drying off
Authors: Buys N. , Vanmontfort D. , Peeters R. , van Isterdael J. , Decuypere E. , Kühn E. R.
Published: September 2010

The effect of bromocryptine on milk production was investigated in 32 crossbred ewes (Flemish Milksheep х Suffolk) with one sucking lamb, during lactation and during drying off. After weaning the lambs, all ewes were hand milked twice daily for 3 days. From day 4 onwards, the ewes were divided into four groups with equal mean daily milk production. Ewes of groups A and B were hand milked twice daily during the following 9 days. Ewes of groups C and D were dried off by reducing the milking frequency. They were milked on days 5, 8 and 12. In groups B and D, bromocryptin (1 ml of 1 g/l ethanol 50%) was injected intramuscularly twice daily while control ewes (groups A and C) received 1 ml ethanol 50%. Blood samples were taken by venipuncture prior to each injection and were assayed for prolactin, growth hormone, thyrotropin and cortisol.

Bromocryptine decreased plasma prolactin levels but did not alter growth hormone or cortisol concentrations during lactation or drying off. Thyrotropin levels were elevated by bromocryptine during drying off but were unaffected during galactopoiesis.

During lactation the daily milk production remained unchanged in control ewes while in bromocryptine-treated ewes a proportional decrease of 0·5 was observed. In all ewes the decrease in milk production occurring at drying off could not be accelerated or stimulated by bromocryptine.

It is concluded that prolactin plays an important role in galactopoiesis in ewes but its role is comparatively unimportant compared with other factors during mammary involution.
Responses in adipocyte dimensions to divergent selection for predicted carcass lean content in sheep
Authors: Bishop S. C. , Cameron N. D. , Speake B. K. , Bracken J. , Ratchford I. A. J. , Noble R. C.
Published: September 2010

Adipocyte dimensions of subcutaneous fat, sampled by biopsy at the 13th rib, were measured in 20-week-old rams from lines of Texel-Oxford and Scottish Blackface sheep, both divergently selected for carcass lean content. A total of 163 animals were measured, with close to equal numbers per breed-line combination. In both breeds, the high (lean) selection line had significantly lower backfat depths (0·71 mm in the Texel-Oxford and 0·83 mm in the Scottish Blackface, s.e.d. = 0·14 and 0·13 mm, respectively), but body weight did not differ between the lines. The ultrasonic fat depth differences between the Texel-Oxford selected lines were accompanied by increases in adipocyte diameter, area, diameter standard deviation within each sample and implied cell number, calculated as the ratio of ultrasonic fat depth to average adipocyte diameter. In the Scottish Blackface sheep there were no selection line differences in adipocyte dimensions, but there was an increase in implied cell number in the line selected for increased fatness. Across breeds, ultrasonic fat depth was correlated with both adipocyte diameter and implied adipocyte number (r = 0·58 and 0·75, respectively), but these latter two measurements were uncorrelated with each other.
Effects of nutrition in utero and in early life on the subsequent lifetime reproductive performance of Scottish Blackface ewes in two management systems
Authors: Gunn R. G. , Sim D. A. , Hunter E. A.
Published: September 2010

Over 3 years, a flock of Scottish Blackface ewes was managed so that one-third of the ewes received a high level of nutrition during the last 100 days of pregnancy (P), one-third received a high level of nutrition during the first 100 days of lactation (L) and one-third received a low level of nutrition as derived from a hill grazing over the same two periods (C). From these ewes, 496 ewe lambs were retained at weaning (19 to 22 weeks of age), balanced for treatment, year and birth type. At 6 months of age half of the lambs, similarly balanced, were transferred to an upland grazing system (U) for three breeding years. The other half was retained on the same hill grazing as their mothers for the same period (H). At the end of the study, all ewes were fed to reduce the range in body condition at a synchronized mating and ovulation rates were determined at slaughter.

Differences in live weight of ewes due to treatment between groups P, L and C had disappeared by 18 months. There were no pre-mating differences between treatments in live weight or body condition score except that ewes in group P had higher live weights than those in group C at condition scores greater than 2·75. There was little effect of grazing system on the differences between treatments in live weight or body condition score at 30 and 42 months but H ewes were heavier and fatter at 18 months of age. Ewe mortality was consistently less in group L than in groups P and C and on system H than on system U, although the differences were not statistically significant. Group L had fewer barren ewes than groups P and C, and barrenness was significantly greater in the U than the H system. Group C had proportionally more single than multiple births than either groups P or L.

At the end of the study there were no differences between the treatments in the proportion of ewes successfully mated at the final mating nor in their ovulation rates in relation to pre-mating body condition.

It is concluded that nutrition during either the lactation period or late pregnancy period can influence subsequent lifetime reproductive performance and that this was expressed through an effect on embryo or foetal loss since there were neither residual differences apparent in live weight or condition score nor in ovulation rate potential.
The responses of growing pigs, of different sex and genotype, to dietary energy and protein
Authors: Fuller M. F. , Franklin M. F. , McWilliam R. , Pennie K.
Published: September 2010

Intact male pigs from two nucleus breeding herds (one predominantly Duroc, DM; the other purebred Large Wliite, LM) together with intact male (RM), castrated male (RC) and female (RF) commercial hybrid pigs were given one of two diets, with the same balanced protein (180 or 240 g/kg) at three daily rates, the highest being ‘to appetite‘. Six replicates of 30 pigs were allocated to these regimes at 40 kg: one replicate was slaughtered immediately to determine initial carcass composition; the remaining pigs were slaughtered at 85 kg when carcass fat and specific gravity (SG) were measured. For two replicates this was followed by dissection and chemical analysis: daily gains of carcass lipid and protein were estimated directly for these two replicates and predicted from carcass weight and SG for the other three. Fed ‘to appetite’, castrated males and females ate more than males; LM pigs ate least. All males grew faster than females or castrated males, the DM pigs the fastest, these rankings being relatively insensitive to feeding level. However, both in daily weight gain and daily protein accretion only the males responded to additional dietary protein. Daily body protein accretion of DM pigs increased linearly with intake on both diets whereas LM pigs showed little response to the highest level of feeding. At the same daily protein intake all pigs had higher rates of body protein accretion on the low protein diet, showing that they were sensitive to additional dietary energy. Results indicate that an animal's superiority may result from a greater efficiency of protein utilization or a higher lean growth potential but that these two characteristics are not simply related.
Separate and combined effects of ephedrine and caffeine on protein and lipid deposition in finishing pigs
Authors: Oksbjerg N. , Sørensen M. T.
Published: September 2010

Two experiments were conducted to examine the effects of dietary inclusion of an ephedrine (Eph)/caffeine (Caf) mixture on finishing (55 to 100 kg live weight) castrated male pigs. The first experiment was conducted as a dose-response study and showed that the mixture had an optimal effect on performance and carcass composition at a dietary inclusion level of approximately 56/560 mg/kg of Eph and Caf, respectively. In the second experiment, interactions between the compounds were studied by dietary inclusion of Eph (56 mg/kg) and Caf (560 mg/kg) separately or as a mixture (56/560 mg/kg). The mixture reduced food intake by 0·12 and improved the food: gain ratio by 0·08. Muscle protein deposition rate was increased proportionately by 0·25, lipid accretion rate was decreased proportionately by 0·27, and gross energetic efficiency of energy deposition decreased proportionately by 0·09. This resulted in a changed proportional carcass composition towards more muscle (0·08) and less fat (0·21) after treatment with the mixture. The reduction in food intake was sustained due to an interaction over the first 3 weeks of treatment changing to additive effects by the compounds. The increased muscle protein deposition rate after feeding the mixture was entirely due to Eph, while the decreased gross energetic efficiency of energy deposition was caused by Caf. On the other hand, both compounds contributed almost equally to the decrease in lipid accretion rate. These results show that an Eph/Caf mixture markedly improves performance and body composition in finishing castrated pigs.
On the use of opportunity costs in deriving the economic value of herd life
Authors: Groen A. F. , van Arendonk J. A. M. , Goddard M. E. , Vollema A. R.
Published: September 2010

This paper presents the economic perspectives applied when either using or not using opportunity costs of postponed replacement in deriving the economic value of herd life. Results show the equivalence of the rescaling method and the correction for opportunity costs. In economic terms, using rescaling or correction for opportunity costs forces the value of genetic improvement to change from revenues of increased output to reduction of costs per unit of (fixed) ouput. Under the zero profit theory, the economic value of herd life is equal when either using or not using correction for opportunity costs. In deriving economic values to define breeding goals, the choice of a method and price parameters will have to depend on foreseen future production circumstances for the system under study.
Effect of lairage during 24 h of transport on the behavioural and physiological responses of sheep
Authors: Cockram M. S. , Kent J. E. , Jackson R. E. , Goddard P. J. , Doherty O. M. , McGilp I. M. , Fox A. , Studdert-Kennedy T. C. , McConnell T. I. , O'Riordan T.
Published: September 2010

The effects on the behavioural and physiological responses of sheep of providing rest, food and water (lairage) during 24 h of either road transport or stationary confinement (treatment) were investigated. Twenty-four hours of continuous treatment was compared with 12 h of treatment followed by either 12 h of lairage, 3 h of lairage or 3 h of food and water on the vehicle, followed by a second 12 h of treatment. A further group of sheep was kept as controls. The plasma cortisol concentration was increased at the start of the journey and after 24 h of continuous transport it was still greater than that in controls (P< 0·05). Apart from a mobilization of body energy reserves as indicated by raised plasma concentrations offree fatty acids after 12 h and β-hydroxybutyrate after 24 h there was no evidence that the welfare of the sheep during the journey was compromised after a particular time. During the lairage and immediately after the second 12-h transport period, the sheep appeared to be hungry. Although sheep transported for 24 h without lairage drank more post transport than controls, there was no biochemical evidence of dehydration during the journey. The sheep lay down during the journey and there was no apparent difference between lairage treatments in the proportion of scans spent lying down during either the second 12-h treatment period or during the first 12 h post treatment. There were fewer potentially traumatic events during the second 22 h of the 24-h journey than during the first 12 h of the journey and no apparent effect of lairage during the journey on the frequency of potentially traumatic events during the second 12-h period of transport.

There was evidence to suggest that a period of lairage during a 24-h journey can be beneficial in providing sheep with an opportunity to eat, drink and avoid the stressors associated with transport. However, providing hay and water on the vehicle during a 3-h stationary period as compared with unloading into a lairage cannot be recommended. Although sheep readily ate hay on the vehicle, they did not drink sufficient water. This resulted in dehydration and a greater plasma cortisol concentration during the remainder of the journey than in those that had been lairaged for 12 h and a greater water intake post transport than in those given either no lairage or 12 h of lairage.
The growth and development of nine European sheep breeds. 1. British breeds: Scottish Blackface, Welsh Mountain and Shetland
Authors: Friggens N. C. , Shanks M. , Kyriazakis I. , Oldham J. D. , McClelland T. H.
Published: September 2010

The objective of this study was to assess the growth and development of carcass composition of entire male and female lambs of three British hill breeds (Scottish Blackface, Welsh Mountain, and Shetland), from weaning to approaching maturity, when kept under conditions designed to be nutritionally non-limiting. Lambs were weaned at 8 weeks of age and given a high-quality pelleted diet ad libitum until slaughter at one offive different degrees of maturity. The Gompertz growth function was used to characterize, for each genotype, the growth curve and to provide estimates of mature weight. As expected, there were significant effects of breed and sex on both food intake and growth rate. Growth rate was depressed, relative to the Gompertz fit, during the months of October to January, and intake was similarly depressed. The estimates of mature weight for the females of each breed were: Scottish Blackface, 69; Welsh Mountain, 61; Shetland, 46 kg. The mature weights of the males were found to be not significantly different from 1-3 times the mature weight offemales. Relationships between carcass composition and live weight were derived by allometric regression. This study provides the first full description of the growth and meat production potential of the three breeds.