bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic components of carcass and meat quality traits in Meishan and Large White pigs and their reciprocal crosses
Authors: Serra J. J. , Ellis M. , Haley C. S. 
Published: September 2010

AbstractThe prospect that genes from the Chinese Meishan pig will be used to improve reproductive performance of European pigs requires that the Meishan is evaluated for traits of economic importance and the genetics of any breed effects investigated. Entire male and female pigs of four genotypes; purebred Meishan (MS) and Large White (LW) pigs and both reciprocal Fl crossbred genotypes (MS ♂ × LW ♀and LW ♂ × MS ♀), were fed ad libitum and slaughtered at about 70 kg. After slaughter, carcass weight, dimensions and conformation were recorded and fat depths at the shoulder, mid back and loin were measured on the carcass, together with fat depths and eye muscle dimensions recorded on a section cut at the last rib position. Drip loss, muscle reflectance and pH were measured and subjective assessments of fat firmness, fat separation, muscle marbling and muscle colour were made. Genotypic means and genetic crossbreeding effects (direct additive and heterosis effects and maternal additive effects) were estimated using restricted maximum likelihood procedures. When compared with the LW, MS carcasses had a similar killing-out proportion but were shorter with a poorer conformation. MS carcasses had substantially greater fat depths and reduced eye muscle dimensions in comparison with the LW. Differences between genotypes for fat depths and muscle dimensions were largely controlled by direct additive gene action, there was little evidence of direct heterosis and hence Fl crosses were intermediate between the purebreds. Significant genotype × sex interaction meant that genotypic differences for these traits were much greater in females than in males. Significant direct additive genetic differences between female genotypes were found for fat firmness, fat separation and drip loss, but these effects may in part have been a consequence of subcutaneous fat depth differences between genotypes. The degree of marbling was greater in MS females than in females of the other three genotypes and these genotypic differences did not seem to be associated with subcutaneous fat depth. Muscle from MS males was darker in colour with a lower reflectance than that from LW males. Genotype × sex interaction was such that genotypic differences for meat and fat quality traits differed between sexes.
The effect of straw on farrowing site choice and nest building behaviour in sows
Authors: Arey D. S. , Petchey A. M. , Fowler V. R. 
Published: September 2010

AbstractFarrowing site choice was examined in 40 sows. In group 1, the preference of 16 sows was tested for pre-formed lying areas which incorporated the characteristics of previously observed farrowing nests: a hollow (H), a mattress (M), a nest box (B) and a flat control (C). None of the sows farrowed on C which indicated that choice was based on some evaluation of the lying surface. However, there was no significant preference for the three nest features: H6, M6, B 4. In group 2, C was replaced by a straw area (S). Four different amounts of straw were offered: 18, 9, 4·5 and 2·25 kg with four, four, eight, eight sows on trial at each amount respectively. All the sows farrowed on S at the 18, 9 and 4·5 levels; at 2·25 kg, three farrowed on S and five moved the straw to other lying areas on which they farrowed. The results indicated that the location of nest material has an important influence on farrowing site choice because it allows the performance of nesting behaviour. Although performance of the behaviour was not affected by the amount of straw available, 2·25 kg appeared to be inadequate for a satisfactory nest.
Teat productivity in second lactation sows: influence of use or non-use of teats during the first lactation
Authors: Fraser D. , Thompson B. K. , Rushen J. 
Published: September 2010

AbstractPrevious research has shown that piglets using the sow's more anterior teats tend to have greater average weight gains, but this difference is often slight in the first lactation and increases in subsequent lactations. In this study, 27 sows were used to determine whether this difference develops because of the piglets' preferential use of the anterior teats during the first lactation. In their first lactation, 14 sows had their anterior teats (pairs 1 to 3) and 13 sows had their posterior teats (pairs 4 to 7) covered so that the piglets could use only one end of the udder. In the second lactation, all the teats were left uncovered and the sucking positions and weight gains of the piglets were studied. Piglets in the second lactation showed the usual preference for anterior teats regardless of which teats had been used in the first lactation. Where the anterior teats had been covered in the first lactation, there was no difference in weight gain between anterior- and posterior-sucking piglets in the 1st week of the second lactation, but a degree of anterior superiority had developed by the 3rd week (P < 0·01). Where posterior teats had been covered in the first lactation, piglets using anterior teats showed substantially greater weight gains than those using posterior teats throughout the first 3 weeks of the second lactation (P < 0·001). Thus, non-use of a teat in the first lactation tended to reduce its productivity, at least in the early part of the next lactation. We conclude that previous non-use of posterior teats can contribute to their tendency for lower productivity, but the effect does not explain completely the greater piglet weight gains usually associated with using the anterior teats.
Estimates of the energy required for maintenance by adult sheep 1. Housed sheep
Authors: Langlands J. P. , Corbett J. L. , McDonald I. , Pullar J. D. 
Published: September 2010

SUMMARYEight adult ewes were fasted for 114 hr. During the last 48 hr. the heat emission of each sheep was measured by direct calorimetry and was found to be 35·2 kcal./kg.0·87/24 hr., that is, 973 kcal./24 hr. for a sheep of 45·4 kg. (100 lb.) live-weight. From this value it is estimated that the 100 lb. sheep would require daily 0·79 lb. digestible organic matter (DOM) from pasture herbage for maintenance.In a second experiment, 49 adult sheep were kept indoors and fed on fresh herbage for a period of 72 days. Measurements were made of the mean daily DOM intake (D), mean live-weight (W) and mean daily weight gain (G) of each sheep. The regression of D on Wk and G, and the underlying or functional relationship between D, Wk and G were both estimated for k = 0·73 and k = 1·0. From the underlying relationships, the preferred equations, the maintenance requirement of a 100 lb. sheep was estimated to be 0·82 lb. DOM daily. This value and those calculated for other live-weights are approximately two-thirds of the corresponding values given in ‘Rations for Livestock’ (Evans, 1960).
Intensive beef production 1. Performance of cattle given complete ground diets
Authors: Preston T. R. , Whitelaw F. G. , Aitken J. N. , Macdearmid A. , Charleson Euphemia B. 
Published: September 2010

SUMMARY1. Seventeen Friesian steers, 25 Aberdeen-Angus crossbred steers and 33 Aberdeen-Angus crossbred heifers were fed on complete ground diets from 3 months of age until slaughter.2. The average time taken from 84 days of age to reach a slaughter live-weight of 400 kg. was 334 days for Friesian steers and 356 days for the crossbred steers. The crossbred heifers took 354 days to reach a slaughter live-weight of 350 kg. Feed conversion efficiency was best for Friesian steers and poorest for crossbred heifers.3. The ratio of hindquarter to forequarter in the carcass did not differ between breeds. There were marked differences in fat development, this being most pronounced in the crossbred heifers and least in the Friesian steers.4. The commercial value of the carcasses was assessed by a score card based on measurements, analysis of the tenth rib cut and visual appraisal. There was no difference between the scores for crossbred steers and heifers but the mean score for the Friesians was considerably lower.
Perinatal deaths among calves in a crossbred dairy herd
Authors: Donald H. P. 
Published: September 2010

SUMMARYAn analysis has been made of still-births and difficulties at parturition in a dairy herd in which purebreds and crossbreds of Friesian, Ayrshire and Jersey origin were kept. There were 2,049 calvings including 28 involving twins.Purebred heifer dams produced 14·7% dead purebred calves (mostly Friesian and Jersey) and 6·4% dead crossbred calves (P < 0·05). For older dams the corresponding values were 2·4% and 3·6% (P > 0·05). Losses were smaller with crossbred dams. Crossbred heifer dams (two-breed crosses) with 6·5% dead calves exceeded older crossbreds with 1·9% dead calves. Three-breed crossbred dams gave similar results (8·2% and 1·2%). An intermediate size of cow of second or later parity was associated with the lowest mortality.Friesian and Hereford sires, the calves by which were heavier than those by Ayrshire and Jersey sires, were associated with greater losses than were the latter but this applies to heifer dams and not to the same extent if at all, to older dams.Of 52 parturitions described as difficult, 31 resulted in dead calves. Malpresentation accounted for 32 cases; the majority of these were ‘hindfeet first’. Friesian and Hereford bulls sired a higher proportion of the calves involved in difficult cases than Ayrshire and Jersey sires.
The nutrition of the early-weaned calf III. Protein solubility and amino acid composition as factors affecting protein utilisation
Authors: Whitelaw F. G. , Preston T. R. 
Published: September 2010

SUMMARY1. Nitrogen balance studies have been conducted on 16 early-weaned calves given four diets containing groundnut meal or herring meal, the protein of which had been rendered soluble or insoluble by different methods processing.2. There were highly significant differences in nitrogen retention between ‘soluble’ and ‘insoluble’ herring meals but no differences between ‘soluble’ ‘insoluble’ groundnut meals.3. ‘Insoluble’ herring meal gave retention values which tended to be higher (significantly so, in one experiment), and ‘soluble’ herring meal gave values significantly lower, than either type of groundnut meal. Mean daily live-weight gains tended to follow the same pattern.4. Blood-urea concentration was significantly lower on the diets containing herring meal than on those containing groundnut meal but within each type meal did not differ according to solubility.5. These results are discussed in the light of in vitro studies on the effect of pH on protein solubility.6. It is concluded that solubility is of minor importance in groundnut meals but of major importance in fish meals when these are included in early weaning diets for calves.7. Under conditions of low or ‘potentially low’ solubility the amino acid content of the protein source appears to be of considerable significance.
Effects in bacon pigs of differing levels of nutrition to 20 kg. body weight
Authors: Nielsen Henning E. 
Published: September 2010

Sixteen blocks of eight littermate pigs were weaned at 3 weeks of age and each divided into four groups. Various levels of nutrition were applied to the pigs so that the four groups reached 20 kg. at 59, 68, 80 and 91 days of age, respectively.Only small differences were observed between groups in feed conversion ratio to 20 kg.; however, Group 4 required more feed per kg. gain than the three other groups.During the second period (20–90 kg.) the pigs in each group were divided into two sub-groups, which were on a high and a low plane of nutrition respectively. In both sub-groups the type of feeding before 20 kg. influenced the average daily gain and feed conversion ratio. The older the pigs were at 20 kg. the higher the daily gain and the lower the feed conversion ratio in the following period. There was an increase in daily feed intake with increased age at 20 kg. for pigs fed ad lib. during the second period.An increase in age at 20 kg. caused a significant decrease in thickness of backfat, a greater area of eye muscle and a smaller area of fat overlying muscle. For pigs fed ad lib. the area of eye muscle was significantly increased by a higher age at 20 kg. live-weight.
Genetic correlation during growth of twin cattle
Authors: Taylor C. S. , Craig Jean 
Published: September 2010

SUMMARYAll possible inter-age genetic correlations were calculated for each of twelve linear body measurements taken at 3-monthly intervals up to 2 years of age on 120 pairs of uniformly reared, liberally fed one-egg and two-egg twin dairy heifers. Genetic correlations between first and second-year mean size are also given. The influences of age, age interval, degree of maturity and body part on genetic correlation are examined.Genetic correlation was in general very high. No significant difference was found between body parts in mean genetic correlation over the period studied. For a fixed age interval, genetic correlation increased with age; from a fixed age, it decreased with lengthening age-interval.The main systematic trends found in the data were accounted for in terms of the amount of development taking place. Genetic correlation appeared to decrease exponentially with difference in degree of maturity, and a formula is given for calculating an approximate value for the expected genetic correlation between size at any two ages. Its range of applicability and its place in a general study of the genetic properties of a population of growth curves are discussed.
An egg transfer study of litter size, birth weight and lamb survival
Authors: Bradford G. E. , Taylor C. S. , Quirke J. F. , Hart R. 
Published: September 2010

SUMMARYIn an egg-transfer experiment, seven breeds of sheep differing widely in mean mature ewe weight were used: Oxford Down, 96 kg; Borderm Leicester, 77; Finnish Landrace, 55; Southdown, 52; Tasmanian Merino, 42; Welsh Mountain, 34; and Soay, 22. Body weight and gestation length of recipient ewes are briefly examined. Of 60 recipient ewes, 95% became pregnant. Embryo survival averaged 69% and appeared to be independent of breed of embryo. Litter size of Welsh Mountain, Border Leicester and Finnish Landrace ewes each given four eggs averaged 2·6, 2·9 and 2·9 respectively so that most of the normally observed breed differences are mainly due to differences in ovulation rate. Observed birth weights were in general agreement with those predicted from litter size and donor and recipient ewe weights. The maternal capacity of Finnish ewes was close to average. Litter size affected survival mainly through its effect on birth weight. For Oxford lambs in litters of 3 to 5 from Finnish recipients, birth weight was 42% that of normal single-born Oxfords and only 42% survived. For Soays the corresponding values were 59% for birth weight and 85% for survival. Finnish lambs were exceptionally small at birth but had the highest viability of all breeds. Lamb mortality was higher for males (18%) than females (9%) especially in large litters (26 v. 11%) but about the same in both sexes for Finnish lambs.
Relationships between haemoglobin type and copper concentrations in whole blood and its components in sheep of different breeds
Authors: Wiener Gerald , Hall J. G. , Hayter Susan , Field A. C. , Suttle N. F. 
Published: September 2010

SUMMARYCopper concentrations were determined in whole blood, plasma and caeruloplasmin and calculated for red cells and non-caeruloplasmin copper in plasma in 215 female sheep, 9 months old, belonging to the Scottish Blackface, Cheviot and Welsh Mountain breeds of sheep and their crosses. Copper determinations were also made on red cells and plasma, and calculated for whole blood, of a contemporary group of 107 female sheep of the same breeds at the age of 4 years. Further, plasma copper concentrations were determined for these 107 sheep from samples taken on several occasions some years earlier.Within breed, sheep of type Hb B had significantly higher levels of copper than sheep of type Hb A in whole blood and most of the blood components. The biggest differences were found in plasma and were 19 ng/100 ml for one group and 37 Jig/100 ml for the other. Type Hb AB sheep were intermediate in copper level. The differences in plasma copper level associated with Hb type were present and of similar magnitude at different ages, seasons and average flock levels of copper.After adjustment for the effects of Hb type, breed differences in copper levels were significant for whole blood and all components but much less pronounced for red cells than for plasma. Copper levels in plasma and red cells were only moderately correlated (r = 0·23–0·40).Combined evidence suggests the existence of a gene with a marked effect on copper level which is linked to the locus for Hb type.
Genetic aspects of voluntary food intake in the pig and their association with gain and food conversion efficiency
Authors: Wyllie D. , Morton J. R. , Owen J. B. 
Published: September 2010

ABSTRACTData from 1357 boarsad libitumfed on a performance testing scheme were analysed to explore the genetic aspects of voluntary food intake. The heritabilities of food intake, daily gain and food/gain were found to be 0·23, 0·41 and 0·18 respectively. The correlations obtained between gain and intake of 0·63 (phenotypic) and 0·89 (genetic) were typical of those reported forad libitumfeeding but greater than those reported for semi-restricted. Estimates of genetic correlation between gain and efficiency ranged from 0·64 to zero and for the phenotypic correlation from 0·44 to zero and were smaller than those reported for restricted feeding. Correlations between intake and efficiency were highly negative on the phenotypic level but small and of variable size genetically, in contrast to reports of small phenotypic and positive genetic correlations under restriction.
A note on the heritability of litter traits in pigs
Authors: Strang G. S. , Smith C. 
Published: September 2010

ABSTRACTEstimates of heritability for 9 litter traits were derived from data on 38 000 Large White and 35 000 Landrace litters by daughter-dam regression (parities 1 to 5) and by a three-level nested half-sib analysis (parities 1 to 3). The regression and half-sib heritability estimates were similar and overall the estimates were quite low, averaging 7% across traits and breeds. This is in general agreement with estimates from two other large-scale European analyses of field data. Some other reports, including lesser experimental material, show rather higher heritability values.
Coordinated trials on the protein requirements of sows 2. A comparison of two levels of dietary protein in gestation and four in lactation
Authors: Greenhalgh J. F. D. , Baird Barbara , Grubb D. A. , Done S. , Lightfoot A. L. , Smith P. , Toplis P. , Walker N. , Williams D. , Yeo M. L. 
Published: September 2010

ABSTRACT1. Gestation diets formulated to contain A, 9 or B, 11 % protein, and lactation diets with C, 13; D, 15; E, 17 and F, 19 % protein provided eight treatment combinations. They were given at 2 kg/day in gestation and approximately 5·7 kg/day in lactation to sows at eight centres, which remained on experiment for 3 to 5 parities and produced in total 529 litters. Mean results for parities 1 to 3 are given in this summary.2. Sows given more protein during gestation (i.e. diet A v. B) gained more weight in gestation (18·3 v. 22·5 kg net gain) but lost more in lactation (—1·7 v. —5·2 kg). Their offspring were significantly heavier at birth (1·31 v. 1·36 kg) and at 3 weeks old (5·28 v. 5·49 kg), but not at 6 weeks old (weaning).3. Giving more protein in lactation caused linear increases in piglet weights at 3 and 6 weeks, and a linear reduction in creep feed consumption. From a sample of sows whose milk yields were recorded, extra protein appeared to increase milk yield and its protein content. Extra protein for lactating sows also reduced their live-weight loss in lactation, but this effect was partially counterbalanced by smaller gains in gestation.4. No treatment had consistent significant effects on litter size or on the interval from weaning to conception. There were no significant interactions between gestation and lactation protein concentrations.5. The generally large differences between centres were in a few cases associated with centre × treatment interactions, but these were not such as to cast doubt on the general applicability of the main findings of the experiment.6. From this and an earlier experiment the minimum protein level for diets based on barley was concluded to be 11 % during gestation and 15% during lactation. For lactation diets, however, the economic optimum level may be > 15 %.
The inheritance and effect on production of polledness in four crossbred lines of beef cattle
Authors: Frisch J. E. , Nishimura H. , Cousins K. J. , Turner H. G. 
Published: September 2010

ABSTRACTChanges in the frequency of the poll gene and the effect of polledness on production were measured from 1970 to 1979 in four closed lines of crossbred cattle. The lines were Africander cross (AX), Braham cross (BX) and two Hereford × Shorthorn (HS lines, one selected for production (HSS) and one a control line (HSR).Calves were classified as horned, polled or scurred. Except in the HSS line, horned males were more common than horned females. Horned HS bulls sired only horned calves when mated to horned cows but corresponding matings of AX and BX breeds produced some polled progeny. The incidence of scurs was highest in the AX line, lowest in the HS lines and higher in males than females. These observations are discussed in relation to existing models of inheritance of horn-type.Prior to 1970 the frequencies of the poll gene declined from their initial values in the BX and HS lines and increased in the AX line. These changes were ascribed to random genetic drift. After 1970 the frequency of the poll gene remained stable in all lines.No significant differences were observed between horned and polled cattle in live weight, fertility or mortality rates indicating that polledness had no detrimental effect on production in these lines.
Digestible energy content of meat meals and meat and bone meals for growing pigs
Authors: Batterham E. S. , Lewis C. E. , Lowe R. F. , McMillan C. J. 
Published: September 2010

ABSTRACT1. The digestible energy content of 14 meat meals and meat and bone meals produced from different regions in eastern Australia was determined using growing pigs. The relationship between digestible energy content and chemical constituents in the meals was investigated.2. Digestible energy ranged from 9·4 to 13·9MJ/kg (air-dry basis). This variation in digestible energy was best described by the regression equation:3. Simpler equations, with only gross energy or crude protein and ether extract were:4. Digestibility of the energy and crude protein in the meals ranged from 0·63 to 0·77 and 0·73 to 0·91 respectively. These variations were not related to any of the major chemical constituents of the meals.