bluuebunny/crossref_metadata_2025 huggingface dataset:
Individual variation in feeding and growth of piglets: effects of increased access to creep food
Authors: Appleby M. C. , Pajor E. A. , Fraser D.
Published: September 2010

Consumption of solid food before weaning and growth before and after weaning were studied in 24 litters of eight to 13 Yorkshire × Landrace piglets per litter. From day 21 until weaning at day 28,12 litters were provided with a single two-space feeder, while the other 12 litters were provided with four similar feeders. Daily food intake by each litter was recorded throughout this period and feeding behaviour of individual piglets was filmed during the final 24 h. On the one-feeder treatment there were 4·1 (s.e. 0·6) piglets per litter which fed very little on the day before weaning (< 0·005 of sample video frames). These tended to have high birth weights and high growth rates on days 0 to 21, but low growth rates on days 28 to 42. Conversely, piglets which fed most on creep food were often those which had gained least on days 0 to 21. The four-feeder treatment increased average intake in the last 3 days before weaning and reduced the number of piglets which fed very little in the final 24 h to 0·6 (s.e. 0·3) per litter. However, neither average growth after weaning nor the occurrence of poorly performing individuals was different between treatments. Furthermore, regression analysis of factors related to weight gain from days 28 to 42 showed that feeding behaviour proportionately accounted for 0·02 only of within-litter variation and food intake on days 21 to 28 did not contribute significantly to between-Utter variation. These results suggest that low consumption of solid food before weaning is a predictor of poor growth after weaning, but not a cause.
Energy and protein utilization and partition in rabbit does concurrently pregnant and lactating
Authors: Parigi-Bini R. , Xiccato G. , Cinetto M. , Dalle Zotte A.
Published: September 2010

Changes in body composition during lactation in 40 primiparous rabbits were studied by comparative slaughter. The results were used to determine the utilization of digestible energy (DE) and digestible protein (DP) and their partitioning between maternal body, milk and foetal tissues.

Twelve does were slaughtered immediately after their first parturition (first slaughter group) to estimate initial body composition. The 28 remaining does were remated 1 to 3 days after parturition and divided into two groups offered a pelleted diet at different levels: group L, fed ad libitum and group R, fed 0·75 of ad libitum. The 19 does that were pregnant (10 of L group, 9 of R group) were kept in individual metabolism cages until their second parturition. They were then slaughtered with their litters.

Milk yield was higher (147·0 v. 117·2 g/day, P < 0·02) and live-weight loss was lower (–42 v. –294 g) in group L than in group R. The food intakes were 304·7 and 234·4 g/day, respectively. Body composition of the does changed substantially between the first and second parturition, with a considerable loss of fat and some loss of protein. A large decrease in empty body (digesta-free body) weight was observed in both groups. The loss of energy corresponded to proportionately 0·32 and 0·41 of the initial body energy, in L and R groups respectively.

The DE requirement for maintenance was estimated to be 468 kj/day per kg M0·75 and the efficiencies of utilization of DE and body energy for milk production were 0·63 and 0·76, respectively. The efficiency of utilization of DE for foetal tissue synthesis was estimated to be 0·27 throughout pregnancy. The DP requirement for maintenance was 3·80 g/day per kg M0·75 and the efficiency of utilization of DP for milk protein production was 0·76 and of body protein 0·61. The efficiency of utilization of DP for foetal protein synthesis was 0·46.
Carry-over of aflatoxin from cows' food to milk
Authors: Veldman A. , Meijs J. A. C. , Borggreve G. J. , Heeres-van der Tol J. J.
Published: September 2010

Two experiments were made. In experiment 1, dairy cows in early lactation (2 to 4 weeks) and dairy cows in late lactation (34 to 36 weeks) were given aflatoxin B, (AFBt)at a level of 34 to 39 fig/day by feeding them contaminated compound food. The aflatoxin Mrcontent(AFMj) of raw milk was determined four times during the experimental period of 14 days. The milk yield was measured daily.

The carry-over rate of aflatoxin was proportionately 0·062 and 0·018 for cows in early and late lactation respectively. This difference was not only due to milk production level but possibly also associated to AFB, liver metabolism.

In experiment 2, eight high (40 kg milk per day) and eight low (16 kg milk per day) milk yielding cows, carry-over of AFB1 from compound food into AFM, in milk was measured at different levels ofAFB7 intake ranging from 7 to 57 fig/day. Independent of AFBj-intake, high-producing dairy cows had a higher carry-over rate than low producing animals (proportionately 0·038 v. 0·025). Carry-over ofAFB1 to AFM, was linearly correlated with milk yield. Variations in the level of AFM1 in milk of individual cows were not due to variations in milk yield. The relationship between AFB2 intake per day and AFM^content in milk per kg could be described by the formula: AFMj (ng/kg milk) = 119 AFB, intake (fig per cow per day) + 1·9. This means that in order to produce milk with less than 0·05 fig AFM, per kg milk the average daily individual intake in a herd should be limited to 40 fig AFB7 per day.

As dairy cows in their early to mid lactation period consume large quantities of compound food, a maximum level of AFB3 in dairy foods has to be set at an acceptable daily intake (ADI) value to guarantee that AFM1 levels in milk do not exceed tolerable levels.
Effect of dietary fat and α-tocopherol level in the lactation diet on the performance of primiparous sows and their piglets
Authors: Babinszky L. , Verstegen M. W. A. , den Hartog L. A. , Zandstra T. , van der Togt P. L. , van Dam J. T. P.
Published: September 2010

A total of 63 primiparous hybrid sows were used in two experiments to study the effect of different fat and α-tocopherol levels in the lactation diet on the performance and milk production of sows and on the performance of sucking piglets. In experiment 1, the major differences in energy sources in the lactation diets were tapioca starch or animal fat. Fifteen sows received the low-fat diet (starch and fat content: 396 and 43 g/kg dry matter (DM)) and 16 sows were given the moderate-fat diet (starch and fat content: 286 and 75 g/kg DM) during 4 weeks of lactation. In experiment 2,16 sows were given a low-fat diet (diet 1: starch and fat content: 418 and 37 g/kg DM) and 16 were given a high-fat diet (diet 2: starch and fat content: 266 and 125 g/kg DM) during 4 weeks of lactation. In diet 2, 68 g animal fat replaced the 200 g starch present in diet 1. The mean α-tocopherol contents of foods in experiment 1 were 14 and 126 mg/kg diet and in experiment 2, 22 and 151 mg/kg diet. The live weight, backfat thickness and milk production of sows were not significantly affected by the different dietary fat levels (P > 0·05). The high dietary fat level increased the DM, fat and energy content of milk and the daily gain of piglets in the second part of lactation in experiment 2 (P < 0·05). The correlation between piglet growth and milk fat and milk energy intake (r) in experiment 1 were: 0·57 and 0·66 and in experiment 2 were 0·41 and 0·40 respectively. The utilization of whole milk and DM, fat, protein and energy content of milk for piglet growth was not influenced by dietary fat level. Varying the level of dietary α-tocopherol did not affect the variables investigated.
Variation during growth of twin cattle
Authors: Taylor C. S. , Craig Jean
Published: September 2010

Phenotypic variances within pairs of monozygotic and dizygotic twin heifers and also genetic variances and heritabilities were calculated for 12 linear body measurements at a sequence of eight ages up to two years old. The 60 pairs of fraternal and 60 pairs of identical twins used were reared as part of a larger uniformity trial in which feeding was effectivelyad libitumthroughout.

Size differences between members of DZ twin pairs were found to be approximately normally distributed with about the same variance for all breeds and crosses. The variance within DZ pairs increased strongly with age, with a marked increase between 9 and 12 months of age and with most body measurements showing a broadly similar trend. On a logarithmic scale DZ variances increased roughly linearly with degree of maturity and at about the same rate in each body measurement. Coefficients of variation within DZ pairs corrected for measuring error had an average value of 2%. They did not change greatly with age, and were roughly the same for most body measurements although width measurements tended to be more variable than average.

Coefficients of variation within MZ pairs had a corresponding overall average of 1·4%; they declined rapidly with age from 2·0% to 1·1%, were roughly the same for all body measurements, but at early ages tended to be greater in late than in early maturing body parts. However, they showed no association with the earliness of maturing of a body part provided variation was measured at the same degree of maturity for each body part.

Genetic variation increased rapidly with age in all body measurements. The rate of increase with age was greater for late than for early maturing parts. The rate of increase with degree of maturity, however, was about the same for all body measurements. Coefficients of genetic variation increased slowly with age; they had an average value of 1·6%.

Estimates of heritability are given at a sequence of eight ages for each of 12 body measurements. They increased strongly with age from 0·14 on average at three months of age to 0·67 on average at two years of age. At any fixed age, early maturing body parts tended to have higher heritabilities than later maturing body parts. However, if heritability was measured at the same degree of maturity in each body part, early and late maturing parts had about equal heritabilities.

The present results are compared with those obtained from twin cattle studies in New Zealand, Sweden and Wisconsin, U.S.A.

Inferences from twins about genetic variances and heritabilities for unrelated animals are discussed.
Prediction of the voluntary intake of food by dairy cows: 1. Stall-fed cows in late pregnancy and early lactation
Authors: Curran M. K. , Wimble R. H. , Holmes W.
Published: September 2010

Data from 22, 28, 36 and 41 pregnant cows in weeks 4, 3, 2 and 1 before calving respectively and 51, 65, 56 and 36 cows in weeks 1 to 4, 5 to 8, 9 to 12 and 13 to 16 of lactation respectively were used in multiple regression analyses to study the feasibility of predicting the daily total and the roughage organic matter and digestible organic matter intakes of cows given known weights of concentrates plus roughage ad libitum. The digestibility of the total intake and of the roughage component, the weight of concentrates eaten per day, the proportion of roughage in the total intake, age, milk yield, fat-corrected milk yield, live-weight gain and the 1·0, 0·73 and 0·66 exponents of live weight were used as independent variables.

The accuracy of the models was assessed from the significance of the partial regression coefficients, the size of the residual standard errors, and the population tolerance limits about predicted values, and by applying selected models to a set of data not included in the study. The results indicated that the precision likely to be achieved in the prediction of intake for individual cows was of limited practical application, but the mean intakes of groups of 30 similar cows could be predicted with an acceptable level of accuracy for practical application. In general, weight of concentrates offered and the digestibility of the roughage were the most effective independent variables in all cows, together with milk yield in lactating cows. The application of the results to conventional feeding systems and to complete diets offered ad libitum is discussed.
The relationship between the month of calving and milk production
Authors: Wood P. D. P.
Published: September 2010

A sample of 6846 Friesian heifers recorded in 672 herds during the year ending 30 September 1968, taken from two areas of England and Wales, has been used to estimate the effect of the calving month on total lactation yield. In both areas, the North and the South-West, a variation amounting to nearly 12% of the mean yield was estab-lished, with lactations resulting from October-December calvings the highest and those from May-June calvings the lowest. There was no evidence of association with particular levels of management, or management systems, as exemplified by a seasonal calving pattern.
Influence of litter size and breed of sire on carcass weight and quality of lambs
Authors: Donald H. P. , Read J. L. , Russell W. S.
Published: September 2010

In order to obtain a wide range of live weights, two Oxford Down, two Southdown, and two Soay rams of recent feral origin, were used to sire lambs from 169 crossbred ewes. These ewes had been bred from Blackface ewes mated to Border Leicester, Dorset Hora, Clun Forest, Finnish Landrace and Tasmanian Merino rams. Of the 282 lambs weaned by the crossbred ewes, 61 were singles, 166 twins, 51 triplets and 4 quadruplets. Carcass data were obtained from all but three of them.

Oxford Down cross lambs were, in terms of fitted values, 10 kg heavier and 4 days younger than Soay cross lambs and 6 kg heavier and 2 days younger than Southdown cross lambs when slaughtered. Twins and triplets were 1·4 and 2·1 kg, respectively, lighter than singles and were 37 and 58 days older than singles. Ewes of the heaviest groups produced heavier lambs in a shorter time than ewes of the lightest groups.

The Soay cross lambs showed a higher killing-out percentage, less tail fat, and more kidney fat, than the Southdown and Oxford Down cross lambs.

Carcass characters made little if any difference to the price paid for the lambs which depended mainly on weight. Receipts from lambs were highest when the most fertile ewes were mated to the largest rams.
A note on rumen ammonia and blood urea levels in steers administered urea or sparingly soluble urea derivates as nitrogen supplements
Authors: Pal R. N. , Negi S. S.
Published: September 2010

Ruminal ammonia and blood urea levels were compared in fistulated steers eating paddy straw to appetite and given urea alone, urea plus oxalate, and complexes of urea with either formaldehyde (UFC) or oxalate (UOC), introduced into the rumen in a single daily dose. The solubilities of UFC and UOC in rumen liquor were 23·7 and 4·6% respectively of that of urea. Higher levels of ruminal ammonia and blood urea were recorded on urea than on other supplements.
Some optimum selection strategies and age structures with overlapping generations
Authors: Hopkins I. R. , James J. W.
Published: September 2010

Genetic responses from selection strategies based on selection among all potential parents of the following year's crop were compared with those based on selection only within progeny crops. In the former group of strategies the duration of stay of an individual in the breeding herd is determined by the estimated breeding value of that individual, whereas in the classic model selected individuals of the same sex all remain in the breeding population for the same period. The former group of strategies, termed ‘parent selection’ strategies, were consistently superior in genetic response to the progeny selection strategies with a very large relative advantage under some conditions. The superiority of strategies that make more efficient use of genetic differences between own or parental age was greater among parent selection strategies than among progeny selection strategies. Similarly, increases in female to male mating ratios, fertility and survival rate generally resulted in larger increases i n genetic response in the more efficient strategies. The effect of changes in number of male and female age groups differs markedly between strategies.
Genetic and phenotypic parameters in performance-tested pigs
Authors: Walters J. R. , Curran M. K. , Kentish P. A.
Published: September 2010

Data were available from 11 474 gilts performance-tested on 137 farms. The data were analysed to provide pooled within-farm sire component estimates of h2and genetic correlations.

Estimates of h2of 0·43 ± 0·10, 0·44 + 0·09 and 0·49 ±009 were obtained for weight for age, C + K and shoulder fat depths respectively in 3583 gilts in 49 Large White herds. Comparable Landrace values derived from 2810 gilts in 43 herds were 0·44 + 0·11, 0·40 ±0·10 and 0·51 ±0·12 respectively. Estimates were consistent from herd to herd.

Estimates of h2made on data from 5081 crossbred pigs, of mainly Large White and Landrace parentage, varied with herd from 0·10 to 0·40 for weight for age and from 0·08 to 0·96 for shoulder fat depth. Significant differences between breeds were found for the genetic correlations between weight for age and the fat depths, and between shoulder and mid-backfat depths. The variance was partitioned into various components. For index score, the within-herd variance averaged 73% of the total variance.
The effect of inflation and form of investment on the estimated value of genetic improvement in farm livestock
Authors: Smith C.
Published: September 2010

High rates of interest (8 to 15%) commonly used in discounted cash flow analysis of genetic improvement schemes have tended to underestimate the value of the returns and to favour breeding programmes with short-term returns. It is shown that inflation should be removed from the interest rate, and an inflation-free rate used in discounting future returns to present-day value.

Various methods for choosing discount rates are discussed. It is concluded that the appropriate rate is the real opportunity cost rate, that is the market cost of borrowing in real terms, in terms of goods rather than money. Taking account of inflation the average cost of borrowing in real terms in the United Kingdom over the past 32 years (1945 to 1976) is estimated as 2 to 3%. This also provides the best available estimate for discounting future returns, and it brings the opportunity cost rate into line with the social time preference rate often proposed for public investments.

The contrast is made between the value of improvements made in the national interest and of those made by breeders or firms. The former benefit from returns on all national commercial production of improved stocks and the returns accumulate and are recouped over many years. On the other hand breeders and firms benefit only from the extra sales of breeding stock due to their temporary marginal superiority over competition and they are often at high risk of getting no returns. Implications to the form and amount of investment in animal improvement are discussed.
The effect of breed and of dried seaweed meal in the diet on the levels of copper in liver, kidney and plasma of sheep fed on a high copper diet
Authors: Herbert J. G. , Wiener G. , Field A. C.
Published: September 2010

Twenty-one mature ewes of each of two breeds, the Scottish Black-face and the Welsh Mountain, were allocated in equal numbers to three diets based on a complete cobbed feed with a 0, 5 and 15% inclusion of dried seaweed meal (Ascophyllum nodosum). All diets were made up to a Cu content of approximately 30 mg/kg by adding CuSO4 to the mix. Sheep were housed and fed individually for 15 weeks.

There was a significant breed difference in the Cu level of the liver dry matter; the Welsh increased by 316 mg/kg compared with 240 mg/kg in the Blackface and the amount of Cu accumulated in the liver per kg feed consumed was 0·66 mg in the Welsh and 0·46 in the Blackface. Diets also had a significant effect; the Cu levels in liver dry matter rose by 323, 293 and 220 mg/kg for the 0, 5 and 15% seaweed diets respectively and the Cu stored per kg feed consumed was 0·66, 0·61 and 0·41 mg respectively. There was no corresponding effect of diet on plasma Cu level, but there was a breed difference with Welsh higher than Blackface. Cu level in kidney dry matter showed a breed-by-diet interaction. Total food consumption did not differ among the treatments, and live-weight and carcass-weight data suggested no adverse effects from the inclusion of seaweed meal in the diet.
A note on the performance and management of calves reared on cold acidified milk replacer fed ad libitum
Authors: Thickett W. S. , Cuthbert N. H. , Brigstocke T. D. A. , Lindeman M. A. , Wilson P. N.
Published: September 2010

Results are presented from six trials dealing with aspects of management on the cold ad libitum system of calf rearing using an acidified milk replacer containing over 600 g skim milk powder per kg.

Thirty-six calves were housed in pens of six for each trial and were fed through a teat and pipeline from a storage barrel. Acidified milk replacer, pH 5·6, was mixed cold at 125 g/1 and made available ad libitum to 3 weeks. A rationed allowance was given daily, on a reducing scale, over the following 2 weeks with weaning completed at 35 days. A pelleted dry food containing 180 g crude protein per kg, together with water in buckets and barley straw in racks, was available ad libitum throughout. Each trial lasted 8 weeks. Results for the mean of the six cold ad libitum trials involving 216 calves were compared with the mean results of 10 conventional bucket-fed trials carried out separately at the same unit, involving 912 calves. All calves were purchased British Friesian male (bull) calves.

Calves on the ad libitum system showed improved live-weight gains of 9·4 kg at 3 weeks, 8·8 kg at 5 weeks and 7·5 kg at 8 weeks, compared with the conventional system. The consumption of milk replacer powder was higher in ad libitum trials at 29·4 kg cf. 12·5 kg by bucket but intake of pelleted dry feed was lower on the ad libitum system at 50·7 kg cf. 71·3 kg to 8 weeks. Calf appearance scores were significantly improved on the ad libitum system which gave the main improvement in performance in the first 3 weeks.
Performance of Friesian cows with high and low breeding indexes 1. Stall feeding and grazing experiments and performance during the whole lactation
Authors: Grainger C. , Davey A. W. F. , Holmes C. W.
Published: September 2010

The performance of 38 Friesian cows with either high or low breeding indexes was measured during the whole lactation and in short-term experiments where the cows were individually given cut pasture in stalls, or grazed on pasture.

Cows with high breeding indexes produced more milk fat than did cows with low breeding indexes in the short-term experiments, and during the whole lactation. There was close agreement between the expected differences (predicted from breeding indexes) and the measured differences in milk fat yield. When fresh cut pasture was given ad libitum in stalls the intake per cow was the same between genotypes. However, when intake was expressed per unit of metabolic weight, the mean pasture drymatter intake of the high breeding index cows was 1·05 of that of the low breeding index cows, but the difference was significant in only one of the four indoor feeding experiments.

The difference between genotypes in size was not regarded as significant because the differences in mean live weight at calving (high breeding index – low breeding index) of the animals purchased in the 1st and 2nd years were –28 and 9 kg respectively. During the whole lactation, low breeding index cows gained significantly more live weight and lost significantly less body condition than did the high breeding index cows. No significant differences in live-weight and body-condition changes could be detected during the shorter periods (4 to 5 weeks) of the indoor feeding and grazing experiments.

It can be calculated that the higher milk production of the high breeding index cows could be explained partly because they eat more (per unit metabolic live weight) and more importantly because they divert a higher proportion of the food they eat to milk production and a lower proportion to live-weight gain than do the low breeding index cows.
A mathematical equation for animal growth from embryo to adult
Authors: Moore A. J.
Published: September 2010

An attempt is made to meet the need for a single standardized growth equation to cover the entire period from conception to adulthood in a wide range of mammalian species. It is suggested that an ideal equation is one which adequately describes the overall shape of a growth curve and, in addition, can be extended or modified to give greater flexibility and higher precision as necessary. The structure of such an equation is discussed and results in the derivation of a logistic relationship between adjustable ‘flexibility’ functions of size and time.

Data from eight species are examined and in both its basic and extended forms the equation is found to give acceptable fits to individual species and to provide a useful mean standardized growth curve for mammals.
Backfat quality in boars and barrows at 90 kg live weight
Authors: Wood J. D. , Jones R. C. D. , Bayntun J. A. , Dransfield E.
Published: September 2010

Forty male commercial hybrid pigs, half castrated at 10 days of age, were used in a study to determine whether boars at bacon weight (90 kg live weight) have different fat quality from barrows. Fat quality was defined as the firmness and cohesiveness of subcutaneous fat, both properties being measured using an Instron materials testing instrument. Within each group of boars and barrows, half the pigs were fed a normal commercial diet and half a lower energy diet at a lower level of food intake. The latter diet provided relatively more energy as C18:2 (linoleic acid).

Firmness of subcutaneous fat was related to fat thickness and to concentrations of the chemical components in the fat which are affected by fat thickness. The single best predictor of firmness was C18:0 (stearic acid). Cohesiveness was less closely related to fat thickness and was most associated with the concentration of C18:2.

On the low energy/high C18:2 diet, all the pigs were judged to have soft fat, the difference between boars and barrows being small and explained by the difference in fat thickness. On the normal commercial diet, some barrows had particularly firm fat but they had thicker fat than any of the boars. Most (0·84) of the pigs in the experiment had P2 values (fat thickness over the m. longissimus at the last rib) between 8 and 15 mm. In this range there was no difference in firmness between boars and barrows. Cohesiveness was also similar between boars and barrows.
The voluntary intake of roughages by steers
Authors: Blaxter K. L. , Wilson R. S.
Published: September 2010

1. Four roughages were given ad lib. to each of eight steers. The amount consumed and the apparent digestibility of the energy of each roughage were determined together with the weight gains of the steers.

2. The mean voluntary intake of dry matter was related to the mean apparent digestibility of the energy of the roughages in the same quantitative way for the steers as had been noted with sheep. Mean weight gains were proportional to the mean number of calories of energy apparently digested.

3. Significant differences between individuals occurred in their voluntary food intakes, and those animals which consumed most digested it least efficiently. The variation in intake from individual to individual expressed as a standard deviation was ±7·5% of the mean.

4. The quantitative similarity of sheep and cattle as far as the relationship between their voluntary consumption of food of different apparent digestibility is concerned, is contrasted with their dissimilarity with respect to fasting metabolism. It is suggested that sheep are likely to prove more efficient convertors of the energy of roughages to body gain than are cattle.

Further work is clearly necessary to explore the extent of these differences.
Growth of bovine tissues 1. Genetic influences on growth patterns of muscle, fat and bone in young bulls
Authors: Berg R. T. , Andersen B. B. , Liboriussen T.
Published: September 2010

Carcass composition and growth patterns for muscle, fat and bone were compared among 277 young male progeny of eight sire breeds, serially slaughtered at 300 kg live weight, 12 months and 15 months of age. The sire breeds were Simmental (SIM), Charolais (CHA), Danish Red and White (DRK), Romagnola (ROM), Chianina (CHI), Hereford (HER), Blonde d'Aquitaine (BDA) and Limousin (LIM). Tissue growth patterns among breeds were examined by regression estimates from the allometric growth equation (Y = axb) and compositional differences were estimated from the intercepts. No significant sire breed differences were found in the regression of muscle, fat or bone on various size dimensions. In regressions involving fat, however, the fattest (HER) had higher regressions and the leanest (BDA) fattened more slowly relative to muscle and bone growth. Breeds differed significantly in amount of muscle, fat and bone when compared at standard weights.

Sire breed ranking for muscle at common bone weights was LIM, BDA, CHA, SIM, HER, ROM, DRK and CHI, while at common carcass weights the ranking was BDA, CHA, LIM, CHI, ROM, SIM, DRK and HER, reflecting differences in fatness. Minor changes in ranking occurred when comparisons were made at a common live weight reflecting differences in dressing percentage. For fat at standard muscle, carcass or live weight the breeds ranked HER, LIM, DRK, SIM, ROM, CHA, CHI and BDA.
Studies in sow reproduction. 2. The effect of lactation length on the subsequent reproductive performance of the sow
Authors: Cole D. J. A. , Varley M. A. , Hughes P. E.
Published: September 2010

Forty litters were weaned from their Landrace × Landrace × Large White dams at 2-day intervals to give a range of lactation lengths from 4 to 42 days. A significant (P<0·001) negative curvilinear relationship was observed between lactation length and the interval from weaning to first oestrus. This period was increased by 4·2 days with the reduction of lactation from 42 to 4 days. The relationship between lactation length and the interval from farrowing to remating was significant (P<0·001) and positively linear over the whole range of observations. A decrease of 1 day in lactation length reduced this interval by 0·91 days. Very short lactations were associated with reduced litter size at the following farrowing; sows weaned after lactation lengths between 4 and 21 days had an average litter size of 9–6 piglets born per litter in the next parity, whereas sows weaned following lactation lengths between 21 and 42 days had an average of 12·7 piglets born in the next parity (P<0·01).
Effect of lactation length of the sow on plasma progesterone, oestradiol 17-β and embryonic survival
Authors: Varley M. A. , Peaker R. E. , Atkinson T.
Published: September 2010

Thirty-three Landrace × Large White multiparous sows were allocated randomly to one of three treatment groups, and were weaned after a 10-day (treatment A), 21-day (treatment B) or 42-day lactation (treatment C). All sows were bled regularly from weaning through to day 24 post coitum, at which time the sows were slaughtered and their reproductive tracts recovered and dissected.

Ovulation rates were similar for all groups. Embryo survival for treatments A, B and C respectively was 0·638, 0·728 and 0·777 but this difference was not significant. Oestradiol 17-β concentrations were significantly higher in sows weaned after 10-day lactations throughout the whole period from weaning to day 10 post coitum compared with the other two treatment groups (P < 0·001).
A note on a stochastic model to describe the milk yield of a dairy cow
Authors: Goodall E. A. , Sprevak D.
Published: September 2010

By studying the behaviour of the time series of the difference between the observed values of milk yield and the fitted lactation curve, a stochastic model for milk yield is derived. The model is used to improve the fit of the lactation curve, to forecast milk yield and to generate simulated values of milk yield.
Changes in body composition relative to weight and maturity of Australian Dorset Horn rams and wethers. 1. Carcass muscle, fat and bone and body organs
Authors: Butterfield R. M. , Zamora J. , Thompson J. M. , Reddacliff K. J. R. , Griffiths D. A.
Published: September 2010

Maturing patterns of carcass muscle, fat and bone and of body organs were established relative to live weight, using data from 20 Dorset Horn rams and 20 Dorset Horn wethers. The sheep were fed a pelleted ration from soon after weaning and individual sheep of both groups slaughtered at 6-kg increments in live weight from 18 kg to maturity at approx. 100 and 96 kg for the rams and wethers, respectively. This small difference in mature weight was mostly due to the weight of the testes and the increased weight of the head in mature rams.

As proportions of live weight, the mature rams had more carcass muscle and bone and less carcass fat than the mature wethers. In the mature animals the body organs in general comprised similar proportions of live weight in the two groups. However the head, hide and blood were proportionately heavier in the mature rams. The liver and alimentary tract were heavier in the mature wethers.

The maturing patterns for the three carcass tissues were not different for the two groups. However, many of the body organs matured on different patterns in the rams and wethers.

As the mature live weights and the maturing patterns for carcass tissues and some body organs were not different for the two groups, comparisons of the proportions of these tissues in rams and wethers would yield similar conclusions on an equal weight basis, as on the basis of the same proportion of maturity. However, comparisons of the proportions comprised by some body organs need to take account of different maturing patterns, as comparisons at different stages of maturity will each give different answers.
Physiological response of swine to cycling environmental conditions
Authors: Bond T. E. , Kelly C. F. , Heitman H.
Published: September 2010

Rectal and surface temperatures, and respiration and pulse rates, were obtained for groups of Duroc pigs that were exposed to air temperatures that varied sinusoidally over a 24-hour period. Two groups averaging 37 and 108 kg were exposed to a constant temperature of 21·1°C and then to temperatures that cycled about a mean of 21·1°C (15·6–26·7°C, 10·0–32·2°C, and 4·4–37·8°C). For a third group averaging 53 kg, the minimum was always near 21·1°C, and the maximum air temperature of the cycle was 33·2, 42·5 or 48·8°C.

The response of rectal and surface temperatures, and pulse and respiration rates, to the various 24-hour cycling air temperatures are discussed and com-pared with inherent daily fluctuations in these responses that are present even when there is no variation in air temperature.
The performance of Finnish Landrace sheep in Britain
Authors: Donald H. P. , Read J. L.
Published: September 2010

A group often female and five male Finnish Landrace sheep were taken to Scotland in 1962. In subsequent purebreeding for four years they and their offspring have shown average litter sizes (at birth) of 2·0, 3·0 and 3·4 for ewes aged one, two and three or more years respectively.

Body weights of breeding ewes prior to mating were on average 72, 106 and 128 lb for ewes of the three age groups.

Mean ewe fleece weights were 4·5 lb with the wide range of 1·7 to 7·1 lb due in part to some shedding of fleece wool in spring. The quality of the true wool in the undercoat was estimated at 54–56's.
The effect of jute coats on the heat losses of two breeds of sheep exposed to different environments
Authors: Webster A. J. F. , Park C.
Published: September 2010

Experiments were carried out to measure the effects of wearing jute coats on the heat production and external insulation of Blackface and Cheviot sheep during exposure to different types of cold environment. The results showed that wearing coats did not appreciably increase external insulation in cold conditions at wind speeds up to 10 mph when the fleece was dry. In cold, wet and windy conditions, wearing coats prevented moisture from penetrating the fleece of the sheep so that external insulation was 25–27 units when the sheep were wearing coats, but only 15–18 units when they were not.

It has been shown that few environments likely to occur in Britain constitute a cold stress for grazing sheep if their external insulation is above 25 units. Wind and rain reduced the external insulation of sheep with full winter fleeces below this value only when they were not wearing coats. It is concluded, therefore, that jute coats have a considerable value in ameliorating the effects of cold stresses of the type likely to be encountered by hill sheep wintered out of doors in the British Isles.
A note on the effect of active immunization against somatostatin on milk production and growth in sheep
Authors: Deligeorgis S. G. , Rogdakis E. , Mantzios A. , Nikolaou E. , Evangelatos G. , Sotiriadis-Vlahos C.
Published: September 2010

It has been reported that a purified extract from sheep hypothalami inhibited growth hormone (GH) release in rats. This somatotropin-release-inhibiting factor (SRIF), or somatostatin, is a tetradecapeptide and has been prepared synthetically (Brazeau, Vale, Burgus, Ling, Butcher, Rivier and Guillemin, 1973). In addition, _SRIF has been reported t o inhibit the release of other hormones which have major effects upon growth and metabolism such as insulin (Koerker, Ruch, Chideckel, Palmer, Goodner, Ensinck and Gale, 1974), glucagon (Ruch, Koerker, Carino, Johnson, Webster, Ensinck, Goodner and Gale, 1973) and thyroid stimulating hormone (Vale, Rivier, Brazeau and Guillemin, 1974). Furthermore, SRIF has also been shown to be present in large quantities i n the gastrointestinal tract where it controls the release of many gut hormones (Schusdziarra, Zyzhar and Rouiller, 1980). Somatostatin seems, therefore, to be centrally involved in regulating digestion and absorption of food and the subsequent distribution of the absorbed nutrients into tissues within the body. Its removal from the blood circulation by passive immunization increased GH concentrations in plasma in rats (Arimura and Schally, 1976) and prevented decreases in GH concentration as a result of stress (Arimura, Smith and Schally, 1976). Similarly, removal of SRIF by active immunization has been reported to result in higher plasma GH levels in lambs (Varner, Davis and Reeves, 1980; Spencer, Garssen and Hart, 1983b). However, this increase in circulating GH did not appear to have a constant effect in later studies and resulted in inconclusive effects on sheep growth. Laarveld, Chaplin and Kerr (1986) and Spencer, Garssen and Bergstrom (1983a) observed increased growth with improved food efficiency in crossbred and Dutch moor lambs respectively, immunized against SRIF, whereas Varner et al. (1980) reported a significantly lower growth rate in male Columbia lambs and others (Fitzsimons and Hanrahan, 1984; Galbraith, Wigzell, Scaife and Henderson, 1985; Garssen, Welling and Spencer, 1984) concluded that immunization against SRIF did not affect growth in crossbred lambs. It has also been reported that immuno-neutralization of SRIF can lead to enhanced milk production early in lactation n i goats (Spencer and Garssen, 1985).
Antiquarian Attitudes: Crossed Legs, Crusaders and the Evolution of an Idea
Authors: Harris Oliver D
Published: September 2010

Since the sixteenth century, both scholarly and popular readings of tomb monuments have assigned a series of interpretations to medieval effigies with crossed legs. These have included the beliefs that the effigies dated from before the Norman Conquest; that they commemorated crusaders, or those who had taken crusading vows; and that they commemorated Knights Templar. The ‘crusader’ theory has proved particularly tenacious, and, although largely discredited by scholars, continues to flourish in folk wisdom. This paper charts the emergence and dissemination of these several ideas and the debates they engendered. It argues that the early modern identification of the cross-legged attitude as a noteworthy feature was, despite its mistaken associations, a landmark in the story of the formulation of techniques for the typological diagnosis of antiquities.
Gildas and the Schools of Cirencester
Authors: Breeze Andrew
Published: September 2010

The life of Gildas by an eleventh-century Breton monk mentions his education at ‘Iren’. Though often taken to mean ‘Ireland’, this is more probably a corruption of ‘Cerin’, the Old Welsh name of ‘Corinium’ or Cirencester. If so, it implies the survival in sixth-century Britain of traditional Roman schools.
What can the absence of anarchism tell us about the history and purpose of International Relations?
Authors: PRICHARD ALEX
Published: September 2010

Anarchism does not feature in contemporary international relations (IR) as a discreet approach to world politics because until very recently it was antithetical to the traditional use-value of a discipline largely structured around the needs and intellectual demands of providing for the world's Foreign Offices and State Departments. This article tells part of the story of how this came to be so by revisiting the historiography of the discipline and an early debate between Harold Laski and Hans Morgenthau. What I will show here is that Morgenthau's Schmittian-informed theory of the nation state was diametrically opposed to Laski's Proudhon-informed pluralist state theory. Morgenthau's success and the triumph of Realism structured the subsequent evolution of the discipline. What was to characterise the early stages of this evolution was IR's professional and intellectual statism. The subsequent historiography of the discipline has also played a part in retrospectively keeping anarchism out. This article demonstrates how a return to this early debate and the historiography of the discipline opens up a little more room for anarchism in contemporary IR and suggests further avenues for research.
Size of Animal in Relation to Productivity with Special Reference to the Ruminant—Economic aspects
Authors: Baker R. D. , Large R. V. , Spedding C. R. W.
Published: September 2010

The economic significance of size in animal production processes manifests itself mainly through an influence on the biological efficiency of the animal population or the individual animal. Within limits, those factors affecting biological efficiency are also ones which have a dominant effect on financial efficiency. These effects relate almost solely to total financial returns and the cost of feeding livestock per unit of product. However, size of animal may have a major impact on the need for resources other than feed, particularly labour and capital, and these aspects also merit some consideration.
Discussion
Authors: Jones J. G. W.
Published: September 2010

The discussion which followed the papers also contained contributions which were related to a paper entitled ‘Focus on Animal Production Research and Development’ and given earlier by Mr W. F. Raymond (Deputy Chief Scientist, Ministry of Agriculture, Fisheries and Food); these contributions are included in this report.
Role of cyclic AMP in the maturation ofCiona intestinalisoocytes
Authors: Silvestre Francesco , Gallo Alessandra , Cuomo Annunziata , Covino Tiziana , Tosti Elisabetta
Published: September 2010

Immature oocytes are arrested at prophase I of the meiotic process and maturation onset is indicated by oocyte nuclear disassembly (germinal vesicle breakdown or GVBD). Signaling pathways that elevate intracellular cyclic AMP (cAMP) may either prevent or induce oocyte maturation depending on the species. In some marine invertebrates and, in particular, in ascidian oocytes, cAMP triggers GVBD rather than blocking it. In this paper, we tested different cAMP elevators in fully grown oocytes at the germinal vesicle stage (GV) of the ascidianCiona intestinalis. We demonstrated that through the activation of adenylate cyclase or the inhibition and phosphodiesterases the oocyte remained at the GV stage. This effect was reversible as the GV-arrested oocytes, rinsed and incubated in sea water, are able to undergo spontaneous maturation and extrusion of follicle cells. In addition, oocytes acquire the ability to be fertilized and start early development. However, morphology of follicle cells, embryos and larvae fromin vitromatured oocytes showed different morphology from those derived fromin vivomature oocytes. The role and the transduction mechanism of cAMP in the regulation of oocyte maturation were discussed. Finally, we indicated a variation of biological mechanisms present in the ascidian species; moreover, we sustain evidence proving that tunicates share some biological mechanisms with vertebrates. This information provided new hints on the importance of ascidians in the evolution of chordates.
Reproductive performance of pigs selected for components of efficient lean growth
Authors: Kerr J. C. , Cameron N. D.
Published: September 2010

Correlated responses in reproductive performance to five generations of divergent selection for daily food intake (DFI), lean food conversion (LFC), lean growth rate on ad–libitum feeding (LGA), and lean growth rate on scale feeding (LGS) were studied. Litter traits were measured on 1220 Large White gilts. Mean litter weights at birth and weaning were 12·9 kg and 63·5 kg, with average litter sizes of 10·3 and 7·9. Responses to selection in the high and low lines for litter size in the DFI and LFC selection groups were 1·9 and –1·5 (s.e.d. VI) at birth and 0·9 and –1·8 (s.e.d. 1·2) at weaning. Responses in litter birth weights were respectively positive and negative for DFI and LFC (3·0 and –2·8 (s.e.d. 1·4) kg) and the response in LGS (3 kg) was greater than in LGA (–0·1 kg). Selection line differences in litter weaning weight followed a similar pattern to birth weight for DFI and LFC (17·5 and –17·3 (s.e.d. 10·1) kg). Responses in litter weights were a result of selection line differences in both litter sizes and piglet weights. The relationships between litter size, litter weights and piglet weights at birth and weaning were essentially linear. An extra piglet at birth and weaning corresponded to an increase of 1·0 (s.e. 0·02) kg and 6·9 (s.e. 0·1) kg in litter weights. Piglet birth and weaning weights were decreased by 0·03 (s.e. 0·003) kg and 0·19 (s.e. 0·02) kg. A uterine constraint on piglet growth was implied, but there was no evidence for a limit to uterine capacity. Heritabilities for litter size, weight and piglet weight at birth of 0·06, 0·11 (s.e. 0·04) and 0·16 (s.e. 0·02) respectively were similar to those at weaning. Common environmental effects on piglet weights at birth and weaning were substantially higher than the heritabilities (0·38 and 0·45, s.e. 0·01). The study indicated that selection for lean growth on either an ad–libitum or restricted feeding regime did not significantly affect reproductive performance, but the high lean food conversion ratio and low daily food intake selection lines had impaired reproductive performance.