The distribution of intermuscular fat (IF) was studied in 24 lambs, of balanced sexes, from each of the Dorset Horn, Hampshire and Clun breeds, which were slaughtered at 42 kg live weight. The Clun lambs yielded the least total IF, the Dorset Horn most and the Hampshire an intermediate amount. The Clun lambs had significantly (P<005) less IF in the thoracic limb than the other two breeds; and the IF content of the neck+thorax region in the Hampshire was lower than that in the remaining breeds. Females had more IF than males in all sites examined. At an equally adjusted total IF weight, sex differences disappeared. The Hampshire yielded more IF in the thoracic limb, pelvic limb and back+abdomen, but, exceptionally, less IF in the neck + thorax than in the other two breeds.

The relative efficiency of voluntary consumption, chemical composition, digestibility in vitro and in vivo, was tested for predicting the nutritive value of five forages: berseem (Trifolium alexandrinum); green oat (Avena sativa); oat hay; cow pea (Vigna spp.) and maize (Zea mays). The digestibility coefficients of dry matter (DM), crude protein, acid-detergent lignin and energy were significantly correlated with DM intake. Digestibilities in vitro of DM and cellulose after 12-h incubation were significantly related to digestibilities in vivo of DM and energy. The values for cellulose digestibility in vitro at 24 h were similar to those for digestibility of energy in vivo. Significant correlations were obtained between the crude protein content of forages and the voluntary DM intake and digestibility of nutrients. Increased cellulose and acid-detergent fibre contents were each related with decreased DM intake and digestibility of nutrients.

Trials involving a total of 401 steers were carried out from 1974 to 1976 to determine the effect of implantation with zeranol on the performance of fattening steers under grazing and feedlot conditions i n Botswana.

Over a 180-day grazing period in 1974, 1975 and 1976 there was a significant improvement in live-weight gain of 11·9, 24·5 and 12·3% i n implanted steers over control steers. Under feedlot conditions there was a mean improvement in live-weight gain of implanted steers over control steers of 17·9% over an average stay in the feedlot of 95 days.

The individual water intakes of 16 (four groups of four) lactating dairy cows, measured on 7 consecutive days, were significantly correlated with dry-matter (DM) intakes (range 4·6 to 14·4 kg/day) and milk yields (range 13·7 to 30·0 kg/day). There was no significant correlation with DM content of the feed (range 833 to 898 g/kg), body weight (range 400 to 620 kg) or mean air temperature (range 7·0 to 20·0°C). Applying a multiple regression analysis to the data, the following relationship was obtained: water intake (kg/day) = 2·15 (± 0·415) × DM intake (kg/day)+0·73 (± 0·197) × milk yield (kg/day) + 12·3 (+ 5·57). After adjusting the data for variations in DM intake and milk yield there was no significant difference between the mean daily water intakes of individual cows. There was, however, a significant day-to-day variation in the mean water intakes of the groups of four cows (P<001) which was not explained by variations in DM intake, milk yield or mean daily temperature.

Measurements of longissimus dorsi pH at 45 min post mortem (pH1) were taken in 27 727 pig carcasses at four bacon factories. The overall least squares mean pH1 was 6·26 and 15·5% of carcasses had pHi values of 5·9 or less. Sex and commercial grade of carcass had little influence on muscle pHi or the incidence of values below pH 6·0. Factory differences were recorded in the distribution of muscle and within each there were marked producer effects in mean and the incidence of values below pH 6·0. Carcasses of Large Whites had fewer muscle pH1 values below 6·0 (12·4%) than those of British Landrace (18·7%), this being mainly due to a large breed effect at one factory. Although breed and testing background of sires of the carcasses examined and the first order interactions with factory had significant effects on muscle pHi and the incidence of values below pH 6·0, they were of little practical significance.