The dry sow is well suited to utilise high fibre diets and there are some suggestions that feeding such diets in pregnancy may enhance litter size and subsequent piglet performance. This experiment was designed to investigate the effects on performance of inclusion of a high level of fermentable fibre in the form of unmolassed sugar beet pulp (SBP) in the diet of dry sows.

24 gilts and 20 multiparous Landrace x Large White sows were allocated to one of two diets according to weaning or entry date, parity and liveweight. The diets comprised a barley/soya basal diet with either 450 g/kg wheat (diet W) or SBP substituting for this wheat to provide the same quantity of corrected digestible energy (diet B). The two diets were fed at differential levels, to supply the same daily total of corrected digestible energy, from weaning or gilt entry until farrowing. The allocated amount of diet was given in a single daily feeding period to animals confined in individual feeding stalls, and a period of one hour was allowed for the ration to be consumed. After farrowing all animals were fed twice daily on a standard diet, according to a scale related to litter size.

The antibiotic Actaplanin is a complex of glycopeptide compounds produced by Actinoplanes missourrensis. When included in feed as a performance enhancer it has been shown to increase milk production of dairy cows (McGuffey et al. 1983). Actaplanin is associated with reduced proportions of acetate and increased proportions of propionate in rumen fluid and a depression in milk fat proportion may result (Clapperton et al. 1987). The aim of the trial reported here was to monitor the effects of feeding 960 mg Actaplanin/head/d to dairy cows throughout two successive lactations.

Information relating to the carcass composition of grass-fattened beef cattle in the UK is not only limited in extent, but is also frequently uni-dimensional, in that the quantitative changes in carcass composition with time cannot be readily assessed. Furthermore, the methods used in selecting animals for slaughter (the visual appraisal of condition) introduces a source of non-random variation that cannot be removed with statistical confidence.

The primary objective of the analysis reported here, therefore, was to evaluate the effects of time on carcass composition and thereby provide information upon which objective production strategies could be based.

48 fattening steers and heifers (16-19 months old and 355 kg liveweight) of two contrasting breed types (Charolais x Hereford x Friesian and Hereford x Friesian) were summer grazed at a stocking rate of 5 animals per hectare. The animals were randomly allocated (at the start of the grazing season) to three slaughter points covering a 12 week period from early July to early October. The commercial saleable meat yield of the left side of each animal was measured together with compositional data from rib sample joints.

There is currently increasing interest in the diversity of materials which may be used as energy sources for dairy cow diets. Feeding of concentrates with a high “digestible fibre” content may be of benefit to the lactating dairy cow. In comparison with a concentrate based on a highly fermentable energy source such as cereal starch a concentrate high in digestible fibre content may undergo a slower fermentation within the rumen such that the resultant fermentation pattern may be altered. Diets and feeding regime's that promote low rumen volatile fatty acid ratios of acetic plus butyric:propionic have been associated with the production of milk of low fat content. Feeding of a high “digestible fibre” concentrate may therefore help prevent this problem. The purpose of the trial reported here was to compare the effects of concentrate energy source on the milk performance of dairy cows in early lactation.

Advantages of the use of test-day records for genetic evaluation of dairy cattle are now widely accepted. In particular, longitudinal models such as random regression avoid using ad hoc extrapolation procedures to reconstruct complete lactations as they provide individual predictions even for incomplete data. However, these predictions and parameter estimates obtained in the model do not take into account the lactation length. This can be an important drawback for phenotypic and genetic analysis of milk production of cows with shorter lactations. The aim of this paper is to propose a methodology that would correct these predictions, weighting them by the probability at each point in time of each cow being dried off. The proposed procedure is easy to implement and calculations are fast to compute. A simulation study and an application on real data for daily milk records show that the proposed methodology provides a more accurate estimation for individual cumulative production as well as genetic values, and avoids predicting negative productions at the end of the lactation as is often the case with random regression models.

1. The results of four experiments on the effects of oral and implanted hydroxyzine on lambs are reported.

2. The effect of hydroxyzine on daily rate of live-weight gain ranged from +7·8% to −6·2% improvement with a mean value of +2·3%.

3. Lambs receiving hydroxyzine in the creep feed manifested significantly higher killing-out percentages and lower thyroid weights than the controls. Pituitary weights were not affected by hydroxyzine.

4. In an experiment on individually-penned, weaned wethers, given a high energy diet, hydroxyzine by either route did not affect live-weight gain but significantly increased killing-out percentage, rate of gain of carcass weight and fat deposition in certain tissues. Hydroxyzine did not affect the fresh weights of the pituitary, thyroid and adrenal glands or the weights of the teats.

This study aimed to investigate the effects and possible interactions of birth weight and n-3 polyunsaturated fatty acid (PUFA) supplementation of the maternal diet on the fatty acid status of different tissues of newborn piglets. These effects are of interest as both parameters have been associated with pre-weaning mortality. Sows were fed a palm oil diet or a diet containing 1% linseed, echium or fish oil from day 73 of gestation. As fish oil becomes a scarce resource, linseed and echium oil were supplemented as sustainable alternatives, adding precursor fatty acids for DHA to the diet. At birth, the lightest and heaviest male piglet per litter were killed and samples from liver, brain and muscle were taken for fatty acid analysis. Piglets that died pre-weaning had lower birth weights than piglets surviving lactation (1.27±0.04 v. 1.55±0.02 kg; P<0.001), but no effect of diet on mortality was found. Lower DHA concentrations were observed in the brain of the lighter piglets compared with their heavier littermates (9.46±0.05 v. 9.63±0.04 g DHA/100 g fatty acids; P=0.008), suggesting that the higher incidence of pre-weaning mortality in low birth weight piglets may be related to their lower brain DHA status. Adding n-3 PUFA to the sow diet could not significantly reduce this difference in DHA status, although numerically the difference in the brain DHA concentration between the piglet weight groups was smaller when fish oil was included in the sow diet. Independent of birth weight, echium or linseed oil in the sow diet increased the DHA concentration of the piglet tissues to the same extent, but the concentrations were not as high as when fish oil was fed.

Multiple trait selection indexes in pig breeding programmes should take into account the population structure and time delay between parent selection and expressions of traits in all production levels next to the trait impacts on economic efficiency of production systems. Gene flow procedures could be used for the correct evaluation of maternal and direct traits of pig breeds involved in breeding or crossbreeding systems. Therefore, the aim of this study was to expand a previously developed bioeconomic model and computer program to calculate the marginal economic values by including a gene flow procedure to calculate the economic weights for maternal and direct traits in pig breeds. The new program was then applied to the three-way crossbreeding system of the Czech National Programme for Pig Breeding. Using this program, the marginal economic values of traits for dam breeds Czech Large White in the dam position and Czech Landrace in the sire position, and for the sire breed Pietrain were weighted by the number of discounted gene expressions of selected parents of each breed summarised within all links of the crossbreeding system during the 8-year investment period. Economic weights calculated in this way were compared with the approximate economic weights calculated previously without a gene flow procedure. Taking into account the time delay between parent selection and trait expression (using discounting with half-year discount rates of 2% or 5%) and including more than one generation of parent progeny had little impact on the relative economic importance of maternal and direct traits of breeds involved in the evaluated three-way crossbreeding system. These results indicated that this gene-flow method could be foregone when estimating the relative economic weights of traits in pig crossbreeding systems applying artificial insemination at all production levels.

Primary growths of perennial ryegrass and red clover were ensiled with formic acid (2 1/t fresh crop), o an equal quantity of formic acid together with formaldehyde (46 or 49 g/kg crude protein in the ryegrass or red clover respectively). The four silages were offered ad libitum to 12 groups, each of five British Friesian steer calves, either alone or with urea or maize starch supplements at 18·4 or 185·2 g/kg total dry-matter intake respectively.

Digestible organic matter and digestible energy intake, live-weight gain, carcass weight, nitrogen retention and all digestibility measurements were higher on the ryegrass silages than on the red clover silages. However, dry-matter intake was higher on the red clover silages.

Formaldehyde treatment reduced lactic and total acid content, and protein degradation in the silages. It also increased intake, live-weight gain and nitrogen retention on ryegrass but not on red clover, the effect being greater when the urea supplement was given. Digestibility measurements were depressed by formaldehyde treatment, although cellulose digestibility was only depressed in the ryegrass silage.

Supplementation with starch depressed silage intake and nitrogen and cellulose digestibility, but increased dry matter, organic matter and energy digestibilities, digestible organic matter and digestible energy intakes, live-weight gain and carcass weight. The positive intake, live-weight gain and carcass weight responses were greater on the silages treated with formic acid, while the digestibility and the live-weight gain responses were greater on the red clover silages. Starch supplementation did not improve nitrogen retention.

The different animal production responses to formaldehyde treatment on the ryegrass and red clover silages are discussed.

The effects on herbage intake of changes of herbage mass associated with different stocking rates were studied in Greyface (Border Leicester × Scottish Blackface) ewes in the autumn. Intake was measured in 5-day periods in late September (PI), late October (P2) and late November (P3) on two established, perennial ryegrass/white clover swards (SI and S2). Both swards had previously been variably stocked to produce areas with a range in herbage masses, some of which were grazed continuously (G) at stocking rates declining from 18 to 6 ewes per ha.

Intake was also measured in P2 and P3 on other areas of the swards which were ungrazed for 6 weeks in September and October (C) and then stocked at 18 ewes per ha. Intakes of dry matter, organic matter and digestible organic matter were 16 g, 10 g and 7·5 g/kg live weight, respectively. Organic matter digestibility was 075 in PI and P2 but declined in P3.

Differences in herbage intake and digestibility arose largely because of differences between the swards in herbage mass, sward height and sward density. Ewes in condition scores > 3·00 in early September had lower intakes at all times than did thinner ewes. Changes in sward management associated with different strategies of use had little long-term effect on herbage intake. Keywords: digestibility, herbage, sheep, stocking rate.

The performance of 273 Hereford calves from lines previously selected for lean growth rate (LGR) or lean food conversion efficiency (LFCR), on a concentrate diet, was evaluated on a grassland diet over a period of 3 years. Both bull and heifer calves were tested, and each year the performance test ran from the 1st week of May (average age of 233 days) until the 1st week of October. Carcass lean content was predicted from body weight and ultrasonic backfat depth, and lean gain was calculated from the product of live-weight gain and predicted carcass lean content. The LGR line was superior to the control (C) line for live-weight gain on test, lean gain on test and lean gain from birth until the end of test. The LFCR line performed similarly to the C line for live-weight gain on test and lean gain on test, but was inferior for total lean gain. For lean gain on test, the proportional differences between the lines were similar to those predicted from parental breeding values for LGR, but they were smaller for total lean gain. The lines did not differ significantly for either fat depth or predicted carcass lean content.

Heritabilities were high for all growth traits, e.g. 0·52 (s.e. 0·17), 0·54 (s.e. 0·17) and 0·59 (s.e. 0·17) for live-weight gain on test, lean gain on test and total lean gain, but lower for fat depth and carcass lean content, 0·25 (s.e. 0·17) and 0·14 (s.e. 0·16), respectively. Genetic correlations with LGR, measured on a concentrate diet, were 0·57 for lean gain on test and 0·56 for total lean gain. If only males were considered, these correlations rose to 0·80 and 0·70, respectively. Coheritabilities between the two environments for lean growth were close to 0·3. It is concluded that although there is some evidence for genotype × environment and genotype × sex interactions, selection for lean growth on a concentrate regimen will still be effective in improving grassland performance.

Efficacy of oestrous synchronization and post-treatment fertility was studied in a herd of 149 dairy goats (Swiss breed no. = 104, indigenous Greek breed no. = 45) kept under an extensive farming system. All does were synchronized during the transitional period (during July prior to the breeding season) using fluorogestone acetate (FGA) impregnated intra-vaginal sponges, equine chorionic gonadotropin (eCG) and different prostaglandin F2a (PGF2α) analogues. Four doses of prostaglandin F2a (group 1: 4·5 mg luprostiol; group 2: 2·25 mg luprostiol; group 3: 0·2 mg cloprostenol; group 4: 0·1 mg cloprostenol) were administered i. m. 48 h prior to the end of progestagen treatment and 400 IU eCG was administered at sponge removal. All does were inseminated with fresh semen (300 ✕ 106 spermatozoa per insemination) 42 to 44 h after sponge removal. There were no significant differences (P > 0·05) in the number of goats showing ovarian activity (blood progesterone concentration ³ 1 ng/ml) prior to oestrous synchronization between PGF2α treatment groups. No significant differences (P > 0·05) were observed for the kidding rates between the treatment groups. Our results indicate that goats with ovarian activity prior to sponge application who received high doses of PGF2α showed lower conception rates than those detected in anoestrus (P 0·05). No differences (P 0·05) were observed in conception rates between groups that received lower doses of PGF2α. July is considered to be a transitional period suitable for oestrous synchronization for both Swiss and indigenous dairy goats. Natural mating during the two subsequent cycles after artificial insemination improved kidding rate, but without any significant difference either between treated groups or between Swiss and indigenous breeds.

In a multibreed experiment 306 females from 25 British breeds of cattle were given a standard pelleted diet ad libitum. Correlations of food conversion efficiency (FCE) with body weight, weight gain, and food intake were studied over 12-week and longer periods from 12 to 72 weeks of age. Inter-age correlations of FCE with itself and the other traits were also studied over age intervals separated by 12, 24, 36 and 48 weeks. The between-breed correlations were genetic while the within-breed correlations were phenotypic.

Between breeds, FCE measured over the full age range from 12 to 72 weeks appeared to be very highly correlated with FCE measured over the 12-week period between 24 and 36 weeks of age. Correlations of 12 to 72 week FCE with traits not requiring measurement of food intake were much lower, being at most 0·77 for weight gain, 0·73 for weight gain per unit body weight and 0·57 for body weight. The pattern of correlations implied that over constant age ranges the larger faster-growing breeds with high intakes tended to be more efficient; however, these correlations were generated primarily at early ages between 12 and 36 weeks and FCE at later ages could not be predicted from other traits measured at earlier ages. Nevertheless, between-breed selection to improve FCE by indirect selection on body weight and weight gain could be effective but there would appear to be no advantage in waiting beyond 1 year of age.

Within breeds, correlations of 12 to 72 week FCE with FCE measured over 12-week periods increased with age from 0·24 to 0·61. Correlations of FCE with weight gain in the same 12-week periods were quite high (0·49 to 0·89) and those with weight gain per unit weight were invaribly higher (0·68 to 0·90). However, as a predictor of FCE in any subsequent period, weight gain per unit body weight was poor and weight gain of no value whatsoever. There was no strong association of FCE with body weight.

The Milk Marketing Board beef shape (BS) score for a sire is derived from the beef conformation assessments made during the routine inspection of his first lactation daughters in the Dairy Progeny Testing Scheme. The trial compared the scores for seven Friesian/Holstein sires with the beef characteristics of their steer progeny. Two groups of cattle, 189 in total, all out of Friesian dams, were used in the trial. The dams were assessed for BS. The cattle were reared on a standard grass/cereal system designed to achieve an overall target live-weight gain of 0·85 kg/day and slaughtered at 530 kg live weight. An assessment of BS was made at seven points during the lifetime of each animal. Carcass classification and assessment together with dissection of the shin joint was undertaken by the Meat and Livestock Commission. In addition to this, 40 carcasses representing high and low BS scores were taken for full dissection of the left side.

The BS score of the dam had no significant effect on the score of the calf at any point during its life. The relationship between the sire BS score and the calf score did not become significant until the calf was 12 months old (P < 0·01) and was still significant immediately prior to the slaughter of the calf (P < 0·05). Carcass conformation scores showed highly significant progeny group differences (P < 0·001). The regression of the sire progeny group means, corrected for estimated proportion of subcutaneous fat, on the sire BS scores was significant (P < 0·001). The carcasses in the high BS score group had a significantly greater weight of lean than those in the low BS score group.

A total of 1855 records were analysed using restricted maximum likelihood (REML) techniques to estimate heritabilities separately for males and females lambs on birth weight (BW), weaning weight (WW), 90-day weight (W90) and average daily gains birth to weaning (Cl) and weaning to 90 days (C2). An animal model including fixed effects of year × season, parity, litter size and rearing type; and random effects of direct genetic effect (h2D) and residual was applied. Estimates ofh2Dfor BWwere 048 (males) and 0·50 (females); for WW 0·35 (males) and 0·22 (females); for W90 0·21 (males) and 0·31 (females); for Cl 0·20 (males) and 0·25 (females); and for C2 0·18 (males) and 0·29 (females).

Data from 2032 Uruguayan Aberdeen Angus cows under extensive management and recording practices were analysed with Bayesian threshold-liability sire models, to assess genetic variability in calving success (CS), defined as a different binary trait for each of the second (CS2), third (CS3) and fourth (CS4) calving opportunities. Sire (herd) variances ranged from 0.08 to 0.11 (0.10 to 0.20) and heritability from 0.27 to 0.35, with large credibility intervals. Correlations between herd effects on CS at different calving opportunities were positive. Genetic correlation between CS2 and CS4 was positive (0.68), whereas those involving adjacent calving opportunities (CS2–CS3 and CS3–CS4) were negative, at −0.39 and −0.54, respectively. The residual correlation CS2–CS3 was negative (−0.32). The extent of uncertainty associated with the posterior estimates of the parameters was further evaluated through simulation, assuming different true values (−0.4, −0.2, +0.2 and +0.4) for the genetic correlations and changes in the degree of belief parameters of the inverse Wishart priors for the sire covariance matrix. Although inferences were not sharp enough, CS appears to be moderately heritable. The quality of data recording should be improved, in order to effect genetic improvement in female fertility.