bluuebunny/crossref_metadata_2025 huggingface dataset:
The prediction of body composition in bacon pigs from measurements of feed intake and live-weight gain
Authors: Houseman R. A. , McDonald I.
Published: September 2010

Predictions of body composition have been made in 24 baconweight pigs of widely differing fatness, using feed intake and live-weight gain data.

Measurements of feed intake and live weight were made every 7 days throughout the growing period from 25 to 90 kg. After each pig was killed at about 90 kg, one carcass side was physically dissected and the whole empty body was chemically analysed. Multiple regression equations were then computed with the dependent variables being the weights of the physically dissectible and the chemical components. The independent variables were initial live weight, energy intake above maintenance, and live-weight gain.

The residual standard deviations of the regressions as a percentage of the mean weights of the dependent variables were for body lipid, 5·6%, fat-free mass, 3·3%, dissectible fat, 6·1 % and dissectible lean, 4·9 %. The predictions seem at least as good as can be achieved by more sophisticated techniques.

Analysis of the data allowed the efficiency of utilization of energy for protein and lipid deposition to be calculated, and an estimate of the energy costs of maintenance to be made.
A note on cuprous chloride as a feed additive for growing pigs
Authors: Braude R. , Mitchell K. G. , Pittman R. J.
Published: September 2010

In two experiments involving a total of 48 individually-fed pigs on experiment from 20 to 90 kg live weight, the addition per kg of diet of 250 mg Cu, provided either by copper sulphate or by cuprous chloride, similarly and significantly improved daily gain and feed: gain ratio. Neither of the supplements had any significant effect on carcass measurements but both markedly and similarly increased the copper content of the liver at slaughter weight.
Cold-induced inhibition of thermal panting in shorn sheep 3. Effect of previous habituation to cold
Authors: Slee J.
Published: September 2010

1. Twenty-six shorn Scottish Blackface sheep received nine daily cold shocks (down to −10°C) each lasting 1 hr. This treatment reduced the metabolic response to cold (lower heart rates) and caused passive body cooling—defined as habituation. Eight selected sheep showing maximum habituation and 16 untreated controls then received blocking treatment (re-shorn and cooled for 2 hr at 18°C or 8°C) before being heat-stressed (at 42°C) to elicit panting.

2. Thermal panting, delayed as expected by blocking treatment, was further delayed by previous cold habituation. Habituated sheep blocked at 18°C panted 30 min later than blocked controls. In habituated sheep blocked at 8°C, panting was completely inhibited even after 90 min heat stress; their final mean respiration rate was 19/min v. 220/min in blocked controls and 250/min in unblocked controls. Rectal temperatures of habituated sheep were lower than controls during blocking treatment.

3. Habituation, by restraining the normal metabolic response to cold, increased the heat debt during blocking treatment and lessened the heat load during subsequent heat stress. This apparently reduced the drive for panting. Habituation may also have favoured a direct inhibitory effect of cold on the respiratory centres.
The effects of dietary energy content and level of feeding on the growth of Israeli-Friesian intact male cattle
Authors: Levy D. , Holzer Z. , Neumark H. , Amir S.
Published: September 2010

In an experiment with group-fed cattle from 6 months of age to slaughter at 480 kg live weight two levels of feed intake: 1, ad libitum, 2, 85% of ad libitum amount, were combined with two ratios of concentrate to hay: a, 70: 30; b, 30: 70. In two further treatments, 3a and 3b, the cattle were fed diets a or b at 70% of ad libitum from 6 to 10 months and ad libitum thereafter.

Daily gain during the first 124 days of the experiment was (in grams) 1293, 983, 1097, 846, 992 and 756, and from the 125th day to slaughter 735, 600, 796, 579, 830 and 714, for treatments la, lb, 2a, 2b, 3a and 3b, respectively. The decline in rate of gain from the first period to the second was inversely related to the level of feed intake and to the percentage of concentrates in the ration in the first period.

Daily carcass gain was 582, 393, 532, 350, 531 and 368 g for treatments la, lb, 2a, 2b, 3a and 3b, respectively.

The treatments that were switched over from 70% of ad libitum feed intake in the first period to 100% in the second (3a and 3b), exhibited considerable compensatory growth in the second period, but this was not sufficient to be of economic advantage.

The overall ME requirement per kg of live-weight gain was inversely related to rate of gain. Of the six treatments, 2a (85% of ad libitum, 70% concentrate) was the most efficient (19·8 Mcal/kg live-weight gain).

Animals on the 100% level of feed intake throughout the experiment (treatments la, lb) were significantly fatter than those on the other treatments.
A note on the velocity of ultrasound in living tissue
Authors: Miles C. A. , Fursey G. A. J.
Published: September 2010

The velocity of sound through the limbs of living animals and through tissue excised from carcasses has been measured. The measurements are compared with calibration velocities recommended by the manufacturers of two sonar instruments used to measure the position of tissue boundaries in animals.
The effect of formalin-treated soya bean meal upon the performance of lactating cows
Authors: Morgan D. J.
Published: September 2010

Four concentrate mixtures were given with grass silage to 52 cows in early lactation in an 8-week randomized block production trial. A further eight cows were used to measure apparent digestibilities of the total diets in a double 4 × 4 Latin-square trial.

The concentrates contained varied proportions of barley, soya bean meal (soya) and formaldehyde-treated soya bean meal (treated soya) together with fixed proportions of wheatfeed and molasses. Crude protein (CP) concentrations in the concentrate mixtures and sources of supplementary protein were 133 g/kg air-dry concentrate, soya (A); 130 g/kg, treated soya (B); 187 g/kg, soya (C); 169 g/kg, soya plus treated soya (D). In the production trial, 9 kg concentrates were given daily together with silage ad libitum, whilst in the digestibility trial the daily ration was 7·6 kg concentrates and 6·6 kg silage dry matter (DM). The silage contained 462 g DM per kg and 140 g CP per kg DM with an in vitro digestibility of DM of 0·7.

The digestibilities of DM, organic matter and energy showed similar trends. Cows given treatments A and B had significantly lower digestibilities of energy than did those given treatments C and D.

Nitrogen digestibility was highest for cows given treatment C and lowest for those given treatments A and B. Silage DM intake and live-weight change were unaffected by treatment during weeks 1 to 8, all treatment groups being in positive live-weight balance in this period.

Milk yields during weeks 1 to 8 were 18·8 (A), 19·6 (B), 20·3 (C) and 20·7 (D) kg/day. Yields for cows given treatments C and D were significantly higher than those for cows given treatment A. There were no differences between treatments for any constituent of milk, but protein concentration in milk tended to be lower for cows given treatment D. During weeks 9 to 20, there were no significant residual effects of treatment upon milk yield or composition.

Parallel regression analysis of milk yield and yields of milk constituents upon CP concentration in the concentrate indicated significant effects of CP concentration on yield of milk, milk fat, protein and lactose during weeks 1 to 8. When examined during weeks 1 to 20 the responses to increased CP concentration were non-significant. The analysis showed a significant positive milk-yield response to formaldehyde treatment during weeks 1 to 8 and 1 to 20. The response in lactose yield was also significant during weeks 1 to 8 and 1 to 20. There was a trend, though not significant, towards an increased milk-fat yield during weeks 1 to 8 for the formaldehyde treatment, whilst protein yield was unaffected.
Body composition of British and Zebu × British cattle in northern Australia 2. Yield of carcass and its relationship to other expressions of composition
Authors: Seebeck R. M.
Published: September 2010

The variation in yield of carcass of Shorthorn-Hereford (SH), Africander x SH (Ax), Brahman x SH (Bx) and late-castrated Brahman x SH (Bx(late)) steers of the F, generation was examined in relationship to rate of growth and other expressions of composition.

On a fasted body-weight basis, yield of carcass was shown to be related to rate of growth. Of the non-dressed-carcass parts of the body, yield of carcass was particularly related to the proportion of gut contents. When this was taken into account, the relationship between yield of carcass and rate of growth was diminished but not eliminated, and breed differences in yield of carcass still remained.

Relationships between yield of carcass (relative to the empty body), carcass composition and offal composition are complex, due to the fact that each of these three shape vectors are related to size and rate of growth. Nevertheless, these shape vectors were shown to be related to each other independently of size. However, there was some confounding between the effect of rate of growth on a given shape vector and the effect of the other shape vector, particularly with respect to the relationship between yield of carcass and carcass composition. Nevertheless, it could be said that the proportion of the variation in a particular shape vector that was associated with variation in rate of growth, is explained more simply in terms of variation in another shape.

Within breed, animals with a high yield of carcass had a high ratio of muscle to bone plus fascia and tendons in the dressed carcass.

The large difference in yield of carcass between breeds.could be accounted for by differences in offal composition, but not by differences in carcass composition. Breed differences in carcass composition at the same size were accounted for by either yield of carcass or offal composition. However, breed differences in the relationship of carcass composition to size were not accounted for by these shape vectors. The effect of yield of carcass on carcass composition was itself accounted for by offal composition.
Effect of passive immunization against testosterone on the reproductive performance of Scottish Blackface ewes in different levels of body condition at mating
Authors: Rhind S. M. , Gunn R. G. , Morris B. A. , Clayton J. , Leslie I. D. , Gittus G.
Published: September 2010

The effect of passive immunization against testosterone on reproductive performance was investigated in 180 mature Scottish Blackface ewes in different levels of body condition at mating. Ewes were fed to achieve a wide range of condition (scores 1·5 to 3·0) by 2 weeks before a synchronized mating. During the week before mating, 90 ewes were each injected with 32 ml of a neat anti-testosterone antiserum (1: 96 000 initial titre) and 90 ewes were untreated. At about 55 days after mating, 50 immunized and 50 control ewes were slaughtered and the numbers of corpora lutea and embryos present were recorded. The proportion of immunized ewes that conceived during two periods of mating was in excess of 0·9 in all condition categories. By contrast, untreated ewes in the low condition category (score =£ 2·00) had significantly lower conception rates than ewes in higher condition categories. Immunized ewes with condition scores of 2·50 or less at mating had significantly higher ovulation rates, litter sizes and lambing rates compared with control ewes, while immunized ewes with scores of 2·75 or higher were not significantly different from control ewes in these measurements. There was no effect of immunization on embryo mortality rate, lamb sex ratio, lamb birth weight, or lamb survival rate in the 1st week after birth.
A note on the effect of exposing gilts to a mature boar at 140 days of age
Authors: Walton J. S.
Published: September 2010

Fifty-six Landrace ♂ x Yorkshire ♀ gilts were divided at 140 days of age into four groups in a 2 x 2 factorial design whereby they were exposed continually (BE) or not exposed (NE) to a mature boar and were or were not blood sampled twice weekly for progesterone determinations.

There was no effect of BE on the age at the first or second ovulation. Since detection of oestrus was only 70·80% accurate, BE apparently delayed the onset of first and second oestrus by 16 days (p = 0·06). Blood sampling advanced first oestrus by 15 days (F = 0·07) and second oestrus by 32 days (P = 0·001).

The results suggest that gilts are unlikely to be responsive to boar exposure at 140 days of age, that observations of oestrus alone may be a misleading end-point of the effect of boar exposure and that the use of blood sampling for the measurement of progesterone as an index of ovarian activity may attenuate the response to stimuli intended to advance puberty in the gilt.
The response of store lambs to protein supplementation of a roughage-based diet
Authors: Hassan S. A. , Bryant M. J.
Published: September 2010

The response of 35-kg store lambs to diets containing increasing rumen-undegradable nitrogen (UDN) concentrations was measured by live-weight gain and nitrogen (N) balance. A range of UDN concentrations from 2·4 to 7·2 g/kg dietary dry matter was achieved by supplementing a basal diet of NaOH-treated barley straw, tapioca, extracted rapeseed meal and minerals with both formaldehyde-treated rapeseed meal and fish meal. Sufficient diet to provide maintenance and a growth rate of 150 g/day was given to the lambs, according to live weight. Increasing levels of UDN promoted a linear increase in live-weight gain and N retention. However, the response to fish meal was greater than that for formaldehyde-treated rapeseed meal. The true digestibility of N of formaldehyde-treated rapeseed meal determined in chickens by ileal analysis was low in comparison to that of untreated rapeseed meal.
Use of embryo transfer in genetic improvement of sheep
Authors: Smith C.
Published: September 2010

Embryo transfer following multiple ovulation could allow faster rates of genetic change in sheep, by increasing the effective female reproductive rate. The gains would come from lower generation intervals or increased selection among females, or both. They require good embryo transfer rates at 6 to 8 months of age. These are not adequate at present and need to be improved by research and development, justified by the extra genetic gains shown here to be possible. If high rates of embryo transfer (10 progeny per donor) could be achieved, then, with appropriate selection schemes, the rates of genetic change could be doubled compared with efficient schemes using normal reproduction. This applies to most traits, to those measured before reproductive age (growth traits and carcass traits estimated in the live animal), to female reproductive traits and to wool traits measured at 14 to 16 months of age. With moderate rates of embryo transfer (5 progeny per donor), gains of 50 to 70% in genetic response could be obtained. To limit the rate of inbreeding to moderate levels in a closed selection flock, some 100 to 200 females (1000 progeny) would be required. Application of the methods may be difficult with current breeding structures, and the development of special nucleus selection stocks i s proposed.
The voluntary intake and digestibility of straw diets and the performance of wether sheep as influenced by formaldehyde treatment of soya-bean meal
Authors: Alawa J. P. , Hemingway R. G.
Published: September 2010

In two experiments, straw diets were supplemented with a concentrate mixture containing either untreated or formaldehyde-treated soya-bean meal. In experiment 1, adult wether sheep were given straw/concentrate mixtures in a 3:1 ratio (air-dry basis) in restricted amounts. In experiment 2, these proportions were adjusted to 3:2 and the growing lambs were offered straw at proportionately 0·05 to 0·1 greater than that eaten daily.

In experiment 1, formaldehyde treatment of soya-bean meal depressed apparent nitrogen (N) digestibility (P < 0·001) although diet organic-matter digestibility was not affected. Formaldehyde treatment also tended to reduce N retention in experiment 1, whereas with growing lambs in experiment 2, it led to improved N retention. Plasma urea concentrations were reduced as a result of formaldehyde treatment of soya-bean meal. Digested N was more efficiently utilized by sheep given the treated soya-bean meal diet in experiment 2 but not in experiment 1. Lambs given the treated soya-bean meal diet tended to gain more live weight with marginally superior food conversion ratios while consuming similar amounts of dry matter as those given the untreated soya-bean meal-supplemented diet.
Reproductive performance and survival of young one-humped camels on Kenya commercial ranches
Authors: Wilson R. T.
Published: September 2010

Data are provided from four Kenya ranches relating to seasonality of breeding, age at first parturition, parturition interval, sex ratio, gestation period and the early survival of young in one-humped camels. A total of 799 births was recorded. Births occurred throughout the year with no marked peak, there being no significant correlation of conception with rainfall. Age at first parturition (no. = 37) was 54·3 months. Parturition interval (no. = 460) was 20·2 months and was significantly affected by the random effects of the dam as well as by the fixed effects of the herd and the survival of the previous young. The sex ratio at birth was 1·06 males to 1·00 female. Gestation period was 377·1 days, and was not significantly affected by any of herd, month of conception, sex of young or age of animal. Abortions amounted to 11·6% of all births with the total of pre-weaning losses (including abortions) being 25·7%. Improving familiarity of the owners with the animals and better management could lead to considerable increases in performance.
The effect of dietary energy level and protein: energy ratio on nitrogen and energy balance, performance and carcass composition of pigs weaned at 3 weeks of age
Authors: Zhang Y. , Partridge I. G. , Mitchell K. G.
Published: September 2010

Four diets were formulated from cereals, animal and vegetable protein supplements and tallow, to contain digestible energy (DE) concentrations of 14·1 or 17·1 MJ/kg and crude protein concentrations of 12·7 or 17·0 g/MJ DE in a 2 X 2 factorial design. In each of two experiments, pigs were weaned and allocated to dietary treatments when 21 days old and were fed twice daily to appetite. In experiment 1, six replicates of four male littermates were used. They were individually fed in metabolism cages and continuous energy and nitrogen (N) balances were made from 28 to 63 days of age. In experiment 2, three male and three female pigs were slaughtered at weaning to determine initial body composition, and three replicates of four littermates of each sex were allocated to the dietary treatments. The latter were fed in treatment groups in flat-deck pens and slaughtered at 63 days of age.

In experiment 1, increased energy concentration reduced food intake only slightly and improved liveweight gain and food: gain ratio; higher protein concentration increased gains only at lower energy concentration. Daily N balance improved with increased energy and protein concentration but the response to protein was greater with the low energy diet. Dietary energy was efficiently utilized even with 163 g tallow per kg diet. From 63 days of age until slaughter at 60 kg all pigs were given the same grower diet to appetite. Performance was not affected by previous treatments.

In experiment 2, food intakes were higher than in experiment 1 and tended to be reduced to a greater extent with the higher energy concentration; live-weight gains were similar for all treatments and food: gain ratio tended to improve in response to higher energy and protein concentrations. Dietary energy level had no effect on carcass fat content but the higher protein level reduced fat deposition. N retention tended to be lower for the low energy, low protein diet compared with the other three diets. Dietary effects on the amino-acid composition of the carcass were small. Carcass amino-acid ratios at 3 and 9 weeks were similar to published values and there was a tendency for higher amino-acid concentrations (g/16 g N) at 9 weeks than at 3 weeks.
A note on the effect of zeranol administration on oestrous cycle length and hormonal profiles in cows
Authors: Beal W. E. , Good G. A. , Putney D. J. , Johnson G. L.
Published: September 2010

Zeranol is an anabolic agent with oestrogenic actions commonly used in fattening beef cattle. This experiment was designed to determine the effects of zeranol administration on oestrous cycle lengths, plasma progesterone concentrations and the exhibition of oestrus in mature cows. Administration of 36-mg zeranol implants during the early, middle or later portion of the oestrous cycle did not alter the length or persistence of oestrous cycles, nor were progesterone profiles different from those observed in untreated cows. Some cows that received zeranol exhibited a prolonged oestrus. The regularity of oestrous cycles in cows treated with zeranol indicates that it may be possible to utilize zeranol as an anabolic and lactopoetic agent in post-partum beef cows.
A note on the response of pigs weaned at 28 days to dietary protein
Authors: Campbell R. G. , Taverner M. R.
Published: September 2010

Thirty-six piglets were used to investigate the effect of six concentrations of dietary protein ranging from 155 to 235 g/kg, and corresponding dietary lysine concentrations from 10·1 to 15·4 g/kg, on the performance of pigs weaned at 28 days of age and growing between 7·5 and 20 kg live weight. Voluntary food intake was not significantly affected by dietary protein, and growth rate increased with increase in dietary protein and lysine up to 167 and 10·9 g/kg respectively (0·75 g lysine per MJ digestible energy (DE)). Food: gain ratio improved significantly with each increase in dietary protein and lysine up to 177 and 11·6 g/kg (0·79 g lysine per MJ DE) respectively.
A note on the estimation of milk production in sheep
Authors: Geenty K. G. , Sykes A. R.
Published: September 2010

The two most widely adopted methods for measurement of milk production in sheep suckling lambs, the lamb-weight increment technique and milking-out following administration of oxytocin, give estimates which differ proportionately between 0·05 and 0·28 especially in early lactation (Doney, Peart, Smith and Louda, 1979). It is not easy to determine which method gives the most accurate estimate of milk production in suckling ewes. It is important, however, to understand the circumstances in which discrepancies between methods may occur and their magnitude. This note provides evidence that such discrepancies may vary with nutritional status of the ewe.
A note on the value and methods of correcting milk records for calving interval or days dry
Authors: Brotherstone Susan
Published: September 2010

In formulating a genetic index for use in cow and sire evaluation, there is a need to account for all environmental factors which influence an animal's yield. To this end, milk production records are currently adjusted for, amongst other things, age at calving and month of calving. In Norway, Sweden and West Germany, records are corrected for calving interval, i.e. the number of days between subsequent calvings (Philipsson, Dommerholt, Fimland, Gaillard, Gjøl-Christensen, Lederer, McClintock and Mocquot, 1978), but in Britain no account is taken of calving interval or days dry. Analysis has shown (McClintock, 1982) that both these factors have a significant effect on yield, and hence further investigation into the value and methods of adjusting for these factors was required.
Factors affecting pre- and post-weaning growth and body composition in kid goats of the Granadina breed
Authors: Sampelayo M. R. Sanz , Muñoz F. J. , Lara L. , Extremera F. Gil , Boza J.
Published: September 2010

Thirty-two kid goats of the Granadina breed were used in four trials of three factors: milk type (goat milk and milk replacer), intake level (1·86 and 2·48 maintenance) and slaughter age (15, 30, 45 and 60 days). Weaning was carried out between the 31st and 45th days. The composition of the carcass and its different cuts and the development of the stomach compartments were studied.

Both the high intake level and use of goat milk produced a statistically greater fat proportion in the carcass. At 30 days of age in kids given goat milk at the high intake level the fat proportion of the carcass was 130 g/kg. The variations in bone proportions were inverse to those for fat. The muscle proportions were affected by age, overall. The tissue composition of the different cuts showed similar responses to those in the carcass. The stomach compartments were affected most by age.

The results show that kids of the Granadina breed have a good fattening capacity. The feeding and weaning system used here produced kids by 60 days of age with stomach compartments similar in proportion to those of adult goats.
Breed and sex differences in equally mature sheep and goats 2. Body components at slaughter
Authors: Thonney M. L. , Taylor St C. S. , Murray J. I. , McClelland T. H.
Published: September 2010

Animals from Soay, Welsh Mountain, Southdown, Finnish Landrace, Jacob, Wiltshire Horn and Oxford Down sheep breeds and a breed of feral goats were slaughtered when 0·40, 0·52, 0·64 or 0·76 of mature body weight. The effects of stage of maturity, breed and sex were examined in the following traits: gut content as a proportion of slaughter weight; blood, omental plus mesenteric fat, perirenal fat, alimentary tract, ‘remainder’ of non-carcass parts and hot carcass, each as a proportion of fleece-free empty body weight; also shoulder, rib, loin and gigot joints and their commercially higher-valued (prime) and lower-valued cuts, each as a proportion of carcass weight.

As a proportion, gut content declined as animals matured, as also did blood, alimentary tract, ‘remainder’, prime shoulder, shank and prime gigot. Increasing proportions were internal fat depots, the hot carcass, rib, loin and gigot flank. Males accumulated significantly less internal fat and more shoulder than females.

When equally mature in live weight, males had proportions that were significantly lower for perirenal fat, rib and gigot and higher for shoulder and pelt plus head, feet and organs.

There were significant inter-breed regressions on mature body weight. The proportion of blood, alimentary tract, pelt plus head, feet and organs, and prime gigot declined with breed size, while hot carcass, brisket, rib and loin proportions increased. These regressions were attributed to a non-random sample of breeds. The small Soay breed had proportions of internal fat and hot carcass which were well below average, and higher proportions of blood, alimentary tract and ‘remainder’. Soay sheep also had a higher proportion of commercially higher-valued cuts in the carcass. In contrast, the large Oxford Down breed had low proportions of non-carcass components (except alimentary tract) and high proportions of lower-priced cuts and prime rib. Feral goats had a greater, and Southdown sheep a smaller, proportion of gut content than other breeds.
The effect of age and growth traits on puberty and reproductive performance in the gilt
Authors: Burnett P. J. , Walker N. , Kilpatrick D. J.
Published: September 2010

An experiment involving 320 gilts was conducted to investigate the effects of age and growth traits on puberty attainment and reproductive performance in gilts given boar stimulation with or without exogenous gonadotropins. Following ad libitum feeding during rearing, groups of gilts were stimulated for puberty at one of four ages, namely 130, 150, 170 or 190 days. Within each age group, gilts were selected to maximize the variation in live weight, relocated, mixed and allocated to two treatments in a randomized-block design: (a) mature boar contact (boars only) and (b) boar contact plus an intramuscular injection of 400 i.u. pregnant mare's serum gonadotropin + 200 i.u. human chorionic gonadotropin (boars + PG600). Gilts were mated at puberty and slaughtered at 35 days post coitum.

For the gilts on the boars-only treatment, the interval from stimulation to puberty decreased significantly (P < 0·05) and became less variable with ascending age at stimulation. Increasing live weight at a given age also reduced the interval from stimulation to puberty. Multiple regression equations involving age, live weight and backfat thickness at stimulation and growth rate from birth to stimulation were calculated to obtain a prediction equation for the interval from stimulation to puberty. The effects of age and live weight at mating on ovulation rate, embryo survival and number of live embryos 35 days post coitum were not significant.

For the gilts on the boars + PG600 treatment, 92% attained puberty within 6 days of treatment, with a non-significant trend to improve with increasing age. Mating rates were similar to those on the boars-only treatment (90%). Ovulation rates were higher (P < 0·001) but embryo survival rates were lower (P < 0·001) in the boars + PG600 group, resulting in similar litter size at 35 days post coitum in the boars-only and boars + PG600 treatments. There was a non-significant trend for litter size to increase with age in the boars + PG600 treatment. Thirty-eight of the gilts treated with hormones failed to conceive and 53% were found by ovarian morphology at slaughter to be cycling normally with a tendency for this proportion to increase with age.
Insulin-like growth factor 1, growth and body composition in red deer stags
Authors: Suttie J. M. , Corson I. D. , Gluckman P. D. , Fennessy P. F.
Published: September 2010

Insulin-like growth factor 1 (IGF1) correlates with antler growth and body growth in penned red deer stags. The present study aimed to investigate the relationships among plasma concentration of IGF1, body growth and carcass composition in grazing stags. Twenty-eight 10-month-old stags were kept at pasture from September to February. They were bled, weighed and their antlers measured fortnightly. Plasma was analysed for total IGF1. All stags were slaughtered in February (aged 15 months); organ weights were recorded and the carcasses were analysed chemically for water, fat and ash. The stags began the study weighing 60·7 (s.e. 1·4) kg and were 96·3 (s.e. 2·0) kg at the end. They grew rapidly in spring and early summer but growth rate slowed in mid summer before increasing again in late summer.

Total plasma 1GF1 for each stag throughout the study correlated positively with antler length (P < 0·001), total live-weight gain (P < 0·001), hot carcass weight (P < 0·01), fat-free carcass weight (P < 0·01), carcass fat weight (P > 0·05) and carcass fat percentage (P > 0·05). Thus IGF1 correlated significantly with all measures of body weight except fat. IGF1 correlated positively with antler growth rate (P < 0·001) calculated individually for each stag during each fortnight. IGF1 correlated positively with the spring phase of live-weight gain calculated as above (P < 0·001) but negatively (P < 0·01) with live-weight gain during the late summer growth phase. The relationships between IGF1 and growth in penned stags also pertain in grazing animals, and in addition 1GF1 is closely associated with carcass lean mainly via an overall effect on body size.
A note on composition changes in pig carcasses due to live-weight loss
Authors: Godfrey N. W. , Frapple P. G. , Paterson A. M. , Payne H. G.
Published: September 2010

Growing pigs were fed either ad libitum to 85 kg live weight, or ad libitum to 95 kg and then half maintenance until their live weight was reduced to 85 kg, when both groups were slaughtered. The middles were divided into eye, wedge and belly dorso-ventral portions and dissected. The carcasses of pigs which lost live weight before slaughter had less fat in the wedge, and less fat and muscle in the belly. They also had a greater proportion of the total middle fat and muscle in the eye portion, less fat in the wedge and less muscle in the belly portion.
A note on attainment of puberty of september-born early-maturing ewe lambs in relation to level of nutrition
Authors: Forcada F. , Abecia J. A. , Zarazaga L.
Published: September 2010

The attainment of puberty in September-born early-maturing ewe lambs was studied at Zaragoza (latitude 41° 40' N). Thirty twin Salz females were allocated to two groups receiving two nutrition levels after 3 months of age: high (500 g/day lucerne hay and 500 g/day concentrate) (H) and low (500 g/ day lucerne hay) (L). Oestrus was detected daily by aproned rams. Corpora lutea were counted after oestrus and plasma progesterone levels monitored each week.

In the first breeding season (January to February) the percentage of females showing sexual activity (silent emulation or oestrus and ovulation) was higher in the H compared with the L group (67 and 20%; P < 0/05). Nonpubertal oestrus before the main breeding season was detected in 67% of animals. In the main breeding season and for H and L groups respectively, percentage of females showing silent ovulation before puberty was 67 and 33% and mean age at puberty extended to 319 (s.e. 4-8) and 314 (s.e. 3·7) days. Ovulation rate at puberty was 1·73 (s.e. 0·13) and 1·33 (s.e. 0·15) respectively (P < 0·05).
Effect of processing barley and wheat grain on the digestion of silage-based diets by breeding ewes
Authors: Chestnutt D. M. B.
Published: September 2010

Fifty-six individually penned pregnant ewes were offered silage ad libitum with wheat or barley in a replicated experiment. Each of these cereals was either unprocessed or processed by rolling or milling and was offered at 300 g/day from 6 weeks before lambing and at 600 g/day from 3 weeks before lambing. Five and 2 weeks before lambing, total faeces were collected over 6-day periods. On average proportionately 0·18 of the unprocessed wheat and 0·20 of the unprocessed barley consumed was recovered as intact grain in the faeces. Mean digestibility of the organic matter in the complete diet increased from 726 g/kg on whole to 748 g/kg on rolled and 759 g/kg on milled cereal (P < 0·01) at the 300 g/day level and from 721 g/kg on whole to 766 g/kg on rolled and 772 g/kg on milled cereals (P < 0·001) at the 600 g/day level. When the effect of egested whole grain was removed there was no evidence of an effect of cereal processing on organic matter digestibility and although digestibility of fibre was higher with whole than with processed grain the effect was not significant. Wheat-based diets were more digestible than barley-based diets and, compared with barley, wheat appeared to have a beneficial effect on fibre digestion.
The effect of increasing the proportion of barley straw in pelleted concentrate diets given to lambs on rumen outflow rate and degradation of protein supplements
Authors: Castrillo C. , Lainez M. , Gasa J. , Guada J. A.
Published: September 2010

Two experiments are described in which growing lambs were offered ad libitum two concentrate pelleted diets containing 60 (diet C) or 230 (diet D) g/kg barley straw.

In the first experiment, eight male and eight female lambs were used to determine the outflow rate from the rumen of chromium-mordanted fish meal and soya-bean meal, estimated from faecal marker excretion. Diet D promoted a higher rumen outflow rate (0·0769 per h) than diet C (0·0486 per h); no differences were found either between sexes or between Cr-mordanted protein supplements.

In the second experiment, the rumen degradation of fish meal, soya-bean meal, sunflower meal, pea seeds and sweet lupin seeds was studied by incubating the supplements in polyester bags in the rumens of four lambs, following a change-over design. Increasing the proportion of straw to 230 g/kg increased the rate of nitrogen disappearance from all vegetable supplements, the differences being significant only for pea seeds.

When degradation kinetics and outflow rates were considered together, effective nitrogen degradability of protein supplements was reduced by the increased proportion of dietary straw, indicating a greater influence of rumen outflow rate than of the increased rate of microbial degradation.
A note on the effects of environmental temperature on live-weight gain during fattening of pigs
Authors: Sakai T. , Nishino M. , Hamakawa M. , Yoon C.-S. , Thirapatsakun T.
Published: September 2010

The effect of piggery temperature on daily live-weight gain of triple cross Large White-Duroc pigs was studied. Weaning rate and fattening completion rates were similar among piglets born in different seasons of the year but the average daily weight gain was slower during the early (20 to 40 kg live weight) and intermediate (40 to 60 kg live weight) periods of fattening in the autumn-born group (T < 0·05) whilst during the late period (60 to 80 kg live weight) slower growth rates were found in the summer- and winter-born groups (P > 0·05). In the intermediate period the fastest growth rates (900 g/day) were recorded at piggery temperatures of 16 to 20°C. In the same period the slowest growth rates (602 g/day) were recorded at temperatures of 8°C or lower and at 24°C or higher. The daily live-weight gain during the intermediate period was shown to be related to piggery temperature in a curvilinear manner according to the equation Y = −2·48x2 + 90·44x + 25·37.
Relationship between lamb vigour and ewe behaviour at parturition
Authors: O'Connor C. E. , Lawrence A. B.
Published: September 2010

Maternal behaviour and lamb vigour are both considered major variables affecting lamb survival, but there are few data to describe their relative importance. To investigate the relationship between lamb vigour and maternal behaviour this study compared the behaviour of pure Scottish Blackface lambs with Mule (Bluefaced Leicester ♀. × Scottish Blackface ♂) lambs, all born indoors. Anecdotal accounts suggested a significant reduction in lamb vigour in Mule lambs, a matter also of significant practical importance given the current incease in Mule numbers. Observations on the grooming behaviour of 32 single or twin-bearing ewes, and on the general activity and udder-seeking behaviour of their lambs were made at parturition. In this study, neither ewe grooming behaviour nor general lamb activity were directly related to lamb sucking success. It was shown that, although Mule lambs had high birth weights and stood as quickly as Blackface lambs, they showed significantly fewer sucking attempts (P < 0·01) and took longer to suck successfully (28 min for Blackface v. 55 min for Mules). The inability of Mule lambs to suck successfully was due to their failure to show proper udder-directed behaviour. These results indicate the importance of considering the behaviour of both ewes and lambs as it would seem that it is not ‘poor’ maternal behaviour but inappropriate lamb behaviour that is a limiting factor in lamb survival in the Mule breed.
Selection for carcass lean content in a terminal sire breed of sheep
Authors: Cameron N. D. , Bracken J.
Published: September 2010

A divergent selection experiment for carcass leanness in Texel-Oxford sheep was established to examine the differences between genetically lean and fat animals derived from the same base population. The selection criterion was designed to change body composition without a corresponding change in live weight, using an index of ultrasonic backfat depth and live weight at 20 weeks of age. The index was constructed using estimates of genetic and phenotypic parameters, which were available at the start of the experiment in 1985. The difference between the high and low lines, after 3 years of selection, for the selection index, live weight at 20 weeks of age, ultrasonic backfat and muscle depths was 0·59,1·30 kg, -0·76 mm and 0·88 mm respectively. The estimated difference for carcass lean and fat weight was 0·72 kg and -0·04 kg respectively with 13·5 g/kg and -13·8 g/kg for carcass lean and fat proportion. The realized heritability for the selection index, estimated from the regression of cumulative response on cumulative selection differential was 0·42, with a standard error of 0·25, after taking account of genetic drift. The selection index heritability, estimated with residual maximum likelihood (REML) methodology, was 0·46 (s.e. 0·14). REML heritability estimates for live weight at 20 weeks of age, ultrasonic backfat and muscle depths were 0·20 (s.e. 0·13), 0·35 (s.e. 0·14) and 0·43 (s.e. 0·14) respectively.
Transgene effects, introgression strategies and testing schemes in pigs
Authors: Gama L. T. , Smith C. , Gibson J. P.
Published: September 2010

Strategies of introgressing a transgene into a pig nucleus undergoing mass selection for net merit were deterministically evaluated. They consisted of systematically backcrossing hemizygous transgenic sires to females from the selection nucleus, or vice versa, followed by intercrossing of hemizygous individuals, assuming different levels of heritability (h2), polygenic breeding value of the founder animal, inbreeding depression and constraints in availability of resources. The polygenic breeding value of the founder transgenic animal and inbreeding depression were of negligible importance if backcrossing lasted for at least three generations, and there was little advantage in extending backcrossing much further. The best introgression strategy examined was to backcross selection nucleus sires to hemizygous females, but this was a less efficient strategy in terms of testing transgene effects. Testing the survival of homozygous carriers requires approximately five and 100 matings among hemizygous individuals to detect a reduction in viability of 0·5 and 0·1, respectively. Comparing several candidate transgenes in the first generations of backcrossing is feasible, and does not result in substantial delays in improvement of polygenic breeding value in the selected transgene. If resources are limited, the magnitude of the transgene effect (as a proportion of the mean) that compensates for the genetic lag incurred by its introgression is about 0·1 for most economic traits in pigs. To compensate for less selection while backcrossing and for risk in use, transgenes must have an appreciable effect on economic merit to make their introgression worthwhile, even when the additional costs of transgene production are ignored.
A note on the use of field beans (Vicia faba) in lamb finishing diets
Authors: Caballero R. , Riopérez J. , Fernández E. , Marín M. T. , Fernández C.
Published: September 2010

Two feeding experiments with housed lambs of the Spanish Manchega breed were carried out over 2 years with the aim of assessing the suitability of field beans in lamb finishing diets. In the 1st year field beans were compared with soya-bean meal as a protein source in a factorial experimental design with the proportion of maize in the diet being 0·15, 0·25 or 0·35. In the second experiment the effect of replacing soya-bean meal and sunflower meal by inclusion of field beans at proportions, 0, 0·1, 0·2, 0·3 and 04 of the diet was studied. All diets were isoenergetic and isoproteic. The composition of the diets had no significant effects on the average daily gain or the food conversion ratio in either experiment. Results from experiment 2 showed that the increasing amount of field beans in the basal diet did not affect protein, fat and water content of a loin sample of meat, or fatty acid composition of kidney fat.
A simulation study of the effects of the calving interval on milk yields of dairy cows in fixed time periods
Authors: Genizi A. , Schindler H. , Amir S. , Eger S. , Zarchi M. , Foote R. H.
Published: September 2010

Multiparous cows were assigned before calving to three calving to first insemination intervals. Records of cows conceiving at first or second insemination, were used to construct a model of the lactation curve which incorporated peak production and the effect of progressing pregnancy. The model was used to simulate milk yield during a 4-year period for three production levels and five calving intervals. The model separated the descending part of the lactation curve into a linearly and an exponentially declining component, with the latter becoming distinct at about 20 weeks after conception. Peak yield was negatively correlated with the slope of the linear decline. Within a simulated 4-year period, cumulative milk yields at fixed time periods after calving depended upon the period chosen and the calving-to-conception interval of the cow. Late conceptions resulted in higher cumulative yields at the end of the 1st year, and in lower yields at the 2nd year end, with respect to early conceptions. Smaller differences were found between the intermediate calving intervals. During the 3rd and 4th years the early conceptions had a distinct advantage. Different rates of the linear decline, obtained for the different production levels, changed the magnitude of the yield differences between the calving intervals but not their relative ranking. The model presented offers a means for the suitable choice of the calving cycle according to the length of the period for which a cow is expected to remain in the herd.
Comparisons between genetic variances estimated from different types of relatives in dairy cattle
Authors: Visscher P. M. , Thompson R.
Published: September 2010

Genetic variances were estimated from different types of relatives for a data set of 19038 first lactation fat yield (FY) and fat concentration (FC) records. For FY, h2 estimates were 0·377, 0·322 and 0·377 from an animal model, a sire model and a model using only female relationships. The corresponding estimates for FC were 0·632, 0·628 and 0·610. Regarding sires with most progeny in the data set as levels of a fixed effect slightly increased h2 estimates, most likely through accounting for selection of proven sires. Statistical models were presented to account for heterogeneous genetic variances for males and females in the prediction of breeding values or in estimating variance components. Simultaneously estimating genetic variances for FY from paternal half-sibs, maternal half-sibs, and daughter-dam comparisons, resulted in heterogeneous genetic variance estimates from male v. female comparisons and similar variance estimates from mhs and dd comparisons. For FC, h2 estimates from different types of relatives were similar.

Dam-daughter comparisons provide 0·75 to 0·80 of the information on heritability from female relationships and provide 0·42 to 0·55 of the total information on heritability.
A note on the potential conjoint use of body condition scores and milk protein concentrations as an index of dietary adequacy in lactating dairy cows
Authors: Balch C. C. , Gutierrez A. Argamenteria
Published: September 2010

The relationships between values for milk protein content (MP) and body condition score (BSC) were compared on a group of 30 farms in western Asturias, northern Spain during the autumn of1990. There was a marked positive relationship (P < 0·01) in between-farm variation in the two factors; a similar relationship has been reported from experiments in Scotland. It is suggested that an index based on the deviation of values for MP and BCS from normal or mean values might be useful, especially in advisory work, to indicate rapidly the dietary energy adequacy on individual frms. However, note would have to be taken of the known changes in MP and BCS with, for example, age of cow and stage of lactation