Sibs of five to 11 twin pairs each of five breeds were either slaughtered as veal or as yearling bulls. Highly significant breed differences were evident in the carcass tissue proportions which could be explained on the basis of differences in the physiology of dairy and dual-purpose animals, the former depositing more fat and more bone than dual-purpose breeds. Among the dual-purpose breeds the carcasses of the Pinzgauer (Pi) tended to rank between the carcasses of the Fleckvieh (FV), Braunvieh (BV), Grauvieh (GV) and those of the Friesian (Fr).

The dual-purpose breeds FV, BV, GV had more meat in the hindquarter and in the shoulder than the FR while these in turn had more meat in the brisket and in the flank and shank muscles. Again the Pi group tended to rank between the aforementioned groups.

Within breeds, large differences between twin pairs indicated high heritabilities for carcass tissue proportions and ratios. The heritability of commercial cut proportions was fairly high but the genetic variance was small, the genetic coefficient of variation being less than 0-02. The different degrees of sexual maturity and of carcass maturity also caused differences in the distribution of meat in the carcasses of young male animals.

Significant mean squares for interactions between treatments and breeds, and genetic correlations of less than unity between performance of twin genotypes in veal and in bulls, indicated age and/or rearing system by genotype interactions between and within breeds for various slaughter traits.

Phenotypic correlations between various slaughter traits were low except where part-whole relationships were involved. It is suggested that slaughter at comparable maturity in the respective treatments was the cause of the weak connection between the traits.

In 1,347 parentage cases in cattle it was determined whether conception resulted from the first or second service. Among cows served twice within short intervals (1–11 days) about 20% remained pregnant from the previous service. At an interval of one day this proportion amounted to 37%.

About three-quarters of the cows had service intervals of 18–24 days. In most of these the calving took place between the expected dates according to the two services. In 6% of the cases with intervals of 18–24 days pregnancy resulted from the first service. It was estimated that about 1% of all cows mated twice within these intervals had become pregnant from the first service.

Rules are suggested for when blood grouping should be required for registration of pedigrees in the herd book.

The very wide field of animal behaviour has no more fascinating application than in the bull stud of any artificial insemination centre where the male is subjected to close observation over a long period of time. After a year or two's experience one becomes aware of the qualifications expected of a bull if he is to become a successful A.I. sire. His general temperament must be good, he must be placid and easy to handle, be free from all vices, and be able to produce high quality semen as and when required, and at the same time he must possess superior genetical material so that there is hope of improved production from his progeny.

The progeny test is generally regarded as an important aid to selection in livestock improvement. It is by no means a new method, but it seems to be in the limelight today. The usual methods of selection have brought us to a certain standard of performance, and apparently any further imporvement can only result through the application of the progeny test.

It is worth pointing out that cattle, especially dairy cattle, pigs and poultry have received more attention by the scientist than sheep. This may be due to the fact that these animals are more under the direct control of the breeder than sheep. They require daily attention whereas a hill flock of sheep may not be seen for weeks or months by the breeder. Again one has definite objectives in view when breeding dairy cows or hens; one can weigh the milk and count the eggs but the task of the hill sheep worker is considerably more complicated.

I feel that I have rather a difficult task this afternoon, because there are not many things that I can disagree with in Mr. Moses Griffith’s paper, since we in Montgomeryshire learnt the fundamental things of land reclamation from Cahn Hill, although we think of course that we improved on them in some detail! However, our general methods were what Mr. Griffith finally put into practice at Cahn Hill.

In Montgomeryshire we tackled about 6,000 acres. It was not all directly reseeded, but all was hill land classified as rough grazing. The land fell into three types: Molinia, Nardus and Bracken. Each of these types of vegetation clearly relate to three different soil types. Molinia is wet, heavy clay; Bracken is dry, loam overlying shale; while Nardus comes somewhere between the two.

The response of performance tested purebred Simmental heifers to various superovulatory treatments with ovine FSH was examined in two experiments. The heifers were 12 months old at embryo recovery, had average live weights of 468·4 kg (experiment 1) and 493·2 kg (experiment 2), and were fat (body condition score approx.4·0 to 4·5 units) at embryo recovery. In experiment 1, the effect of administering a total of 9·0 or 10·8 mg ovine FSH (Ovagen) administered as eight equal doses twice daily over 4 days was evaluated. In experiment 2, a total of 9·0 mg ovine FSH was administered either in equal doses in a level pattern or in declining doses twice daily over 4 days.

The response to the low, compared with the high, dose of ovine FSH in experiment 1 was 8·8 v. 10·5 ovulations (corpora lutea); 7·7 v. 7·7 totalova plus embryos recovered; 6·0 v. 4·1 viable embryos; 4·4 v. 3·1 grade 1 embryos (P > 0·05); and 1·7 v. 4·1 non-fertile ova(F < 0·01). In experiment 2, the response to the same total dose of ovine FSH administered in a level compared to a declining pattern was 8·5 v. 10·7 ovulations; 5·6 v. 9·6 total ova plus embryos; 3·1 v. 5·6 viable embryos; 2·5 v. 3·8 grade 1 embryos; and 1·7 v. 2·2 non-fertile ova. It was concluded that, although the differences between the treatments in the yields of viable and grade 1 embryos were not significantly different, there are practical and economic advantages to using a low rather than a high level of gonadotropin and there are no marked disadvantages in these areas to administering ovine FSH in a declining rather than a level pattern of doses.

Field data were analysed in an attempt to identify factors contributing to differences between haemoglobin types n i the proportion of ewes lambing per ewe exposed to the ram in flocks grazing oestrogenic pastures. The number of ewes mated and the proportion of ewes failing to conceive to first service per ewe exposed to the ram were analysed. Neither was found to significantly differ between matings of different haemoglobin type. It is concluded that differences in reproductive performance between haemoglobin types could possibly result from differences in embryo survival.

The objective of this study was to investigate genetic merit of return over feed (ROF), which is a herd profit index defined by CanWest Dairy Herd Improvement as a difference between milk income and feed cost. A multiple-trait (MT) model and random regression model (RRM) were used. The traits analyzed in MT were rearing cost and ROF of the first three lactations. In RRM, a cumulative ROF was fitted as function of age and rearing cost was treated as a correlated trait. Variance components were estimated within a Bayesian framework by Gibbs sampling using a subsample of data. Breeding values were then estimated for 3 041 078 animals using records of 1 951 893 cows. Estimates of heritability for rearing cost from MT and RRM were 0.23 and 0.22, respectively. ROF per lactation and cumulative ROF were negatively correlated with rearing cost. Estimates of heritability of ROF through the first, second and third lactation from MT were 0.27, 0.10 and 0.08, respectively. Estimates of heritability of ROF from RRM increased with age and ranged from 0.08 through 0.31. Estimated breeding values (EBVs) for ROF from MT and RRM were moderately correlated with official EBV for production traits and the Canadian selection index (Lifetime Profit Index). Herd life EBV had −0.07 and 0.19 correlations with EBVs for ROF from MT and RRM, respectively. From both MT and RRM, small favorable correlations were reported between EBVs for ROF and for bone quality and angularity, whereas low unfavorable correlations were reported with EBV for udder depth, front end and chest width. Majority of correlations between EBVs for ROF and for reproduction traits were near 0, with the exception of EBV for gestation length, calf size and calving ease, where small favorable correlations were reported. The ROF is a good indicator of cow profitability despite the fact that it is a simplified profit index that does not account for animal-specific health and reproductive cost. However, because ROF does not account for differences in heritabilities between components of profit, ROF is not recommended to be used for direct selection for profit.

The effect of time after feeding on the distribution of nitrogen (N) in digesta from various segments of the gastrointestinal tract was studied in sheep given a diet of chopped hay once daily. Four groups of four animals were slaughtered at 2, 8,16 and 24 h after feeding and digesta were separated into large (>1180μm), medium (300 to 1180 μm) small (45 to 300 μm) and fine particles and liquid (<45 μm) fractions. The N pool in the reticulorumen decreased with time after feeding but post-ruminal N pools changed very little. Changes in N distribution within the reticulorumen reflected reductions in large particles and increases in fine particles and liquid fractions, the intermediate fractions remaining fairly constant.

Ardacin is an antibacterial glycopeptide with ruminal activity. The objective of this study was to measure its effects on food intake and growth rate of growing and finishing steers. Two experiments were carried out simultaneously using the same foods and the same ardacin supplementation levels. In experiment 1, 72 growing steers (8 months old and 240 kg initial weight) in four treatment groups were individually offered a basal diet of grass silage ad libitum. In experiment 2, 44 finishing steers (19 months old and 463 kg initial weight), also in four treatment groups were individually offered a basal diet of grass silage ad libitum plus 3 kg (5 kg for the final 28 days) concentrates per head daily. The four treatments were 0, 50, 125 and 210 mg ardacin per head daily incorporated into 1 kg ground barley. This was offered in addition to the basal diet. The duration of the experimental period was 154 days after which 48 of the growing steers were put to pasture for a 196-day grazing season. The finishing steers were slaughtered following a withdrawal period of 7 days. Mean daily silage dry-matter intakes, and mean daily total metabolizable energy intakes for the treatments as listed above were 4·91, 5·15, 5·10 and 5·03 (s.e. 0·083) kg and 63, 66, 65 and 65 (s.e. 0·7) MJ (experiment 1), and 5·63, 5·62, 5·51 and 5·54 (s.e. 0·059) kg and 108, 108, 107 and 107 (s.e. 0·4) MJ (experiment 2), respectively. In the same order, mean daily live-weight gains during the treatment period were 612, 758, 784 and 798 (s.e. 25·2) g (experiment 1) and 911, 942, 851 and 860 (s.e. 40·0) g (experiment 2). In the growing steers proportionately 0·64 of the weight response to ardacin was retained to the end of the following grazing season. It is concluded that ardacin supplementation increased live-weight gain and improved the efficiency of conversion of food to live weight in growing steers but had no significant effect on finishing steers in this study.

Three trials with pregnant sows tied in stalls have been conducted to measure the effects on ration digestibility: (a) of a pelleted compound given once or twice per day, (b) of half the daily ration fed as barley at a separate time from the pelleted concentrate and (c) when the order during the day in which the barley and concentrate were fed was reversed.

Giving pelleted complete rations twice as opposed to once per day led to slight improvements in the apparent digestibility of dietary dry matter, grpss energy, crude fibre and phosphorus. When half the daily ration was given as crushed barley in the morning the apparent digestibility of phosphorus was slightly higher than it was when barley was given in the afternoon. Nevertheless the apparent digestibility of dry matter and crude protein was greater for the complete mixture given twice per day. All these effects were statistically significant.

Bovine placental lactogen (bPL) is structurally related to prolactin (PRL) and growth hormone (GH). In synergism with steroid and thyroid hormones, bPL is crucial in stimulating the development of the mammary gland, mammary cell differentiation and function. To further explore whether bPL gene is associated with milk production traits, we herein analyzed single-nucleotide polymorphisms (SNPs) within eight regions of bPL gene, which are potentially associated with five milk production traits on 1028 Chinese Holstein cows. Among these, two SNPs, NT7409(T–C) and Nt11246(G–A), were identified. The former is within exon 2; it induces an alteration of amino acid from Val to Ala. The later is within exon 4. It is a synonymous mutation. We found that there were significant associations between NT7409(T–C) and milk and protein yield. Cows of the AA genotype yielded less milk (P = 0.001) and less protein (P = 0.003) than those of genotypes AB and BB. However, on the NT11246(G–A) locus, no significant association was observed in the five milk production traits studied. In addition, bPL has been localized near markers RM185 and CC549051 with a distance of 23.2 cR on BTA 23. It is at the same position as the region including quantitative trait loci (QTLs) affecting milk and protein yields by previous linkage analysis. In summary, our findings demonstrated that the SNP within exon 2 of bPL (NT7409(T–C)) is associated with two milk production traits, and this provided further evidence that bPL could be a major gene-controlling milk production trait in Holstein dairy cattle.

In poultry and dairy cattle heterosis is occasionally found in crosses of different strains of the same breed (Hutt and Cole, 1952; Johansson, 1939; Nordskog and Ghostley, 1954). Limited data on the milk production of reciprocal crosses between Dutch and American strains of Friesian dairy cattle being available in Israel, an investigation was carried out to determine whether crossing these two strains resulted in a heterotic effect on milk production.

Five castrated male pigs (100±2 kg mean live weight) fitted with T-shaped ileal cannulae were used to determine ileal digestibility of raw or autoclaved (136°C, 3 min, 2·3 bar) kidney-bean seed meals, which were included (536 g/kg) in the diet as the only protein source. A protein-free and a diet based on hydrolysed casein were used to estimate endogenous protein secretion. Apparent ileal digestibility of dry matter was lower (P < 0·05) for raw compared to autoclaved kidney-bean meal. Apparent and true ileal digestibilities of raw kidney-bean meal were not only lower (P < 0·05) than those of autoclaved kidney beans, but negative or close to zero for N and some amino acids. Ileal N (36·9 g/kg food ingested) and sialic acid (3·5 g/kg food ingested) flows in pigs given the raw kidney-bean-based diet were higher (P < 0·05) than those of pigs given the autoclaved kidney-bean diet (respectively 8·9 and 1·4 g/kg food ingested). Autoclaved kidney beans contained 364 and 143 g/kg of starch and non-starch polysaccharides respectively, the ileal digestibilities of which were 0·79 and 0·26. Among individual non-starch polysaccharide sugars, apparent ileal digestibility values were between 0 (rhamnose) and 0·38 (arabinose). Ileal apparent digestibility of total oligosaccharides in the autoclaved kidney bean diet was 0·52, and total amounts of oligosaccharides digested was 18·6 g/kg food. Among individual short-chain fatty acids in ileal contents, only propionate values were signifi cantly (P < 0·05) different between pigs given raw or autoclaved kidney-bean diets. Lactate concentration in ileal contents was higher (P < 0·05) in pigs given autoclaved compared with raw kidney beans. Ileal digestibility of autoclaved kidney-bean meal in the 10-kg pigs was poorer than that of other raw legume-seed meals such as lupins and chickpeas in other studies. The potential health implications of these results are also discussed.

Carcass quality was evaluated in 35 male and 41 female lambs, 38 expressing the callipyge phenotype (Cg) and 38 controls expressing the normal phenotype (N). Lambs were from Romanov and Suffolk × Romanov ewes mated to two rams heterozygous for the callipyge locus and slaughtered at approximately 44 kg live weight. The Cg lambs reached slaughter weight at 163 days of age, 13 days younger, and had a dressing proportion 0·524 , 0·029 points higher. Also they had more leg (341 v. 308 g/kg), less loin (315 v. 328 g/kg) and less shoulder (340 v. 360 g/kg) than the N lambs. The leg, loin and shoulder wholesale cuts and half the carcass of Cg lambs had 81, 113, 77, and 92 g/kg more lean and 52, 98, 59, and 72 g/kg less fat than N lambs, respectively. The Cg lambs also had larger loin-eye area (18·5 v.13·1 cm2), less backfat at the C (4·1 v. 6·1 mm) and at the GR locations (11·0 v. 15·2 mm) and less internal fat (202 v. 339 g) than the N lambs. Dissection of the 12th rib indicated that Cg lambs had more muscle (574 v. 462 g/kg), less fat (276 v. 358 g/kg) (both P < 0·001) and similar (V > 0·05) bone (155 v. 265 g/kg) to N lambs. Colour of the longissimus muscle was significantly paler in Cg lambs. Intramuscular fat and dry matter of longissimus muscle were significantly lower (49 v. 120 and 247 v. 253 g/kg) in Cg than in N lambs. Cg lambs were significantly different (P < 0·05) from N lambs for all traits studied except age at slaughter, tissues at the GR location, proportion of bone in the 12th rib and the L* colour of the longissimus muscle. Breed type effect was significant only for age at slaughter, whereas the effect of sex was significant for all traits except for proportion of lean in the leg, b* colour and intramuscular fat content of the longissimus muscle. No interactions were significant except phenotype × breed type on fat thickness over the longissimus muscle. Post-mortem ageing of the longissimus muscle for 9 or 15 days caused a significant reduction in muscle toughness in Cg lambs compared with those aged for 3 days (113 v. 98 Newtons) but the muscle was still tougher than that from N lambs (with a shear force of 64 and 51 Newtons at 3 and 9 or 15 days post mortem). The principle component analysis including carcass conformation and composition traits as well as meat quality traits was indicative of a distinctly different carcass ofCg compared with N lambs. The first two principal components explained 0·70 of the total variation.

The purpose of this work was to investigate the relationship between individual animal performance and production per unit area of land of steers of different potential growth rate under different grazing stocking rates (SR). The analysis involved 160 steers divided equally between two breeds, over 2 years at four SRfor each breed and two replicates for each SR. Thus there werefive steers per replicate. The breeds were purebred Aberdeen Angus (Angus) and 4 Limousin (Limousin). After weaning steers were grazed for 251 days on a pasture dominated by Festuca arundinacea. Given that equal SR does not equate to equal treament for breeds characterized to be of different size and rate of growth at a given age, the analysis was undertaken on the basis of three categories of metabolic body size per ha (S). The variables analysed were individual live-weight gain (final minus initial weight, kg), relative individual live-weight gain (logefinal weight - loge initial weight) and production (kg/ha). A mixed model was used to examine effects of breed, S, year and the interactions between these variables. In general significant (P < 0·05) differences were found for all factors of classification and interactions. Independent linear regressions were calculated for each breed between absolute live-weight gain, relative live-weight gain, and production on S. It was concluded that there was a genotype × environment interaction, with the Angus breed tending to show a higher production per unit area than the Limousin, especially at high levels of S when scarcity of forage was apparent. Nevertheless Limousin steers had higher absolute individual performance than the Angus. The higher production of the smaller breed may be explained by a higher SR at a given S level and also by its higher relative individual live-weight gain in relation to that of the larger breed. The data were coded to use Mott's model to study the relationship between absolute performance (kg) and production (kg/ha). However this model ignores the existing interaction involving breeds.

A Piétrain × Large White boar and a Large White boar were placed on each of 12 farms where the breeding females were crossbred white sows. Cooperators were requested to obtain 10 litters by each sire and record their performance to slaughter at 60 kg live weight. Breed of sire did not affect litter size or piglet body weight at birth or at weaning, age of progeny at slaughter, carcass mid-line fat depths or colour and condition of the ‘eye muscle’. Piétrain crosses had higher carcass yields (1·8%) and larger eye muscles in cross-section (13·2%) than Large White crosses. They also had less depth of fat above the eye muscle (14 %) but this did not confer any advantage in commercial evaluations.

Animal health issues are a problem on many dairy farms, and much is already known about clinical treatments and the behaviour of sick animals. Animal health issues can influence behaviour seen around the milking parlour, but less is known about the relationship between the number of previous medical treatments and the queuing to be milked, the ‘milking order’. Information was collected on five afternoon milking sessions, the individual cows’ age and the medical treatment history of each cow in a group of 100 cows. The question addressed was whether the age and the medical treatment history of each cow in the herd affected its milking order. In addition, milking order was tested day to day, and was found to be consistent. A significant positive correlation was found between medical treatment history and milking order rank, meaning that cows with a higher medical treatment history tended to enter the milking parlour later than cows with a lower medical treatment history. In contrast with this finding, it was found that older cows were more likely to enter the milking parlour early when compared to younger animals, a finding which is supported by previous studies. These somewhat contradictory effects of (a) age and (b) medical treatment history on milking order suggest that health disorders may have long-term measurable effects on the position of a cow in the milking order, even when the effect of age on milking order is accounted for.