Multiple births were induced in 20 hinds subjected to a progesterone plus gonadotropin treatment to advance the breeding season by about 4 to 5 weeks. In total, over 2 years, 92 hinds were treated and run with melatonin-treated stags. Of the 59 hinds that calved to the induced oestrus, 39 produced single calves, 19 produced twins and one produced triplets. Birth weight, gestation length, perinatal mortality and growth rate to weaning at ca. 20 weeks of age were compared for singles and twins. There was a significant effect of birth type on birth weight with twins being proportionately 0·30 lighter than singles (6·27 and 8-94 kg; P < 0·001), with a significant interaction between the birth weight of a calf and the sex of its co-twin (P < 0·05); males born as co-twins to females were proportionately 0·18 heavier than their co-twin females (P < 0·06), while in contrast twin male sets were substantially lighter than twin female sets. Gestation lengths were similar for both singles and twins, with significant negative relationships between gestation length and birth weight for both singles and twins, with a 2-day decrease in gestation length for a 1-kg increase in mean birth weight. There was a strong quadratic relationship between perinatal survival and birth weight; the expected mortality rates at 5, 8 and 11 kg birth weight derived from the relationship were 0·39, 0·11 and 0·39 respectively, indicating reduced probability of survival at both low and high birth weights. The regression relationships between weaning weight or growth rate to weaning and birth weight indicate that at the same birth weight, twin-reared calves were about 5 kg lighter than singles at 20 weeks, while an extra 1 kg weight at birth was associated with an extra 2 kg weight at 20 weeks.

The efficacy of an enzyme preparation added to barley and rye-based diets given to broiler chickens and containing both β-glucanase and arabinoxylanase activities, was investigated and compared with a well characterized commercial enzyme preparation containing predominantly P-glucanase activity.

Both enzyme preparations significantly improved body weight, cumulative food intake and food conversion efficiency for chickens given both barley- and rye-based diets. For the barley-fed chickens, on average a notable increase in body weight of 171 g at day 13 and 477 g at day 24 was noted, for both enzyme preparations. However, the preparation containing high amounts of both β-glucanase and arabinoxylanase activities was more effective in reducing the incidence of sticky droppings for rye-fed chickens, and, in comparison with previously published data, gave an optimal response at a lower supplementation rate. The results indicate that it is possible to reduce the protein content in enzyme-supplemented broiler chicken diets.

Lambs were fed diets in which peat replaced equivalent alfalfa hay. Gains were depressed by proportionately 0·14, 0·32 and 0·56 due to 100, 200 and 300 g peat per kg, respectively, during a 63-day feeding period. Lambs fed peat required more dry matter per unit gain. Necropsy examination of heart, kidney, liver, spleen, lung, and pancreas revealed no gross abnormalities from feeding of peat. Rib eye area was reduced at 200 and 300 g dietary peat per kg. There were no differences in taste of cooked loin sections due to peat. These studies support the safety of feeding peat for use as a dietary carrier at 20 to 30 glkg diet or as a dietary diluent at higher levels.

Seventy-two Landrace pigs were used to study the effects of dietary crude protein concentration (197, 168 and 137 g/kg air dry meal), sex, type and live weight on the whole- body (gut content included) amino acid composition of growing pigs. Boars and gilts from two types (lean and obese) slaughtered at 20, 30 or 90 kg live weight were used. Mean whole-body amino acid concentrations were: lysine 63·4; methionine 21·8; cystine 15·8; threonine 35·1; leucine 67·7; isoleucine 28·0; valine 40·5; phenylalanine 35·5; tyrosine 24·6 and histidine 26·8 g/kg protein. Dietary protein concentration had no effect on body amino acid composition. Boar values tended to be higher than those of gilts but there were no significant differences. Pigs of the obese type also tended to have higher values than lean pigs, with significant differences obtained for methionine, cystine, leucine, and isoleucine. Apart from cystine, live weight had no effect on whole-body amino acid composition, Cystine content however, decreased highly significantly from 17·1 g/kg protein at 30 kg live weight to 14·3 g at 90 kg live weight P (P < 0·001). When compared with the suggested ideal pattern for essential amino acids leucine and histidine values are higher and isoleucine slightly lower, with no conclusive indication on methionine and cystine.

Shugor, Dubasi and Watish subtypes of Sudan Desert sheep were evaluated on the basis of three productivity indices: (I) weight of lamb weaned per ewe per year; (II) weight weaned per kg ewe per year; and (III) weight weaned per kg0·75 ewe per year. Components used to construct the indices were litter weight at 150 days, parturition interval, survival to 150 days and ewe post-partum weight. There were differences among subtypes in all components but, because of interactions among them, there were no differences in the indices. The indices were 18·5 kg, 461 g and 1·25 kg for I, II and III respectively. Other studies on Sudan Desert and other types of African sheep with similar mature weights have generally shown better results. Suggestions for improving productivity are made.

The effects of monensin sodium, administered by intraruminal controlled-release devices at a rate of 320 mglday, on milk and milk solids production and bloat score were examined in a trial with 90 lactating dairy cows given only mixed ryegrasslwhite clover pasture. Monensintreated cows had significantly greater yields of milk and milk protein than control cows (1397·2 (s.e. 22·9) v. 1296·9 (s.e. 16·3) kg milk, 49·6 (s.e. 0·9) v. 46·5 (s.e. 0·6) kg protein) over the 14-week period of treatment (P < 0·01). Yield of fat was similar in monensin-treated and control cows (62·9 (s.e. 1·5) v. 63·4 (s.e. 1·1) kg). Live weight, condition score and bloat score were not influenced by treatment but pasture conditions were not conducive to severe bloat challenge.

Eight mature Dorset-cross sheep, each fitted with a permanent rumen cannula, were given a diet of chopped barley straw (plus urea and minerals) either with or without an Aspergillus oryzae (AO) fermentation extract (2 glday). The addition of AO fermentation extract to the diet increased the initial rate of straw degradation (P < 0·05) but did not alter the final extent of degradation. Total culturable bacteria increased with AO treatment but numbers of cellulolytic bacteria, ciliate protozoa, and aerobic fungi, were not significantly altered. Rumen pH, liquid clearance rate, total volatile fatty acids, acetate, propionate, butyrate, L-lactate and ammonia concentrations were also unaffected.

One group of five oxen in the Koshi hills of Nepal ate rice straw plus 4 kg fresh weight per day of the fodder tree Ficus auriculata. Another group of five oxen ate only rice straw. Calculations showed both diets were low in rumen degradable nitrogen (RDN). The animals which ate the tree fodder had a higher dry matter (DM) intake than those eating rice straw alone. Both groups consumed less food and lost weight in weeks when they worked for 5 to 6 h (walking 16 km, climbing 600 mlday) than in weeks when they were not walking. No significant differences in digestibility of food were seen. In the weeks after work the group receiving the tree fodder regained weight, while cattle eating only rice straw remained at a lower weight. Supplementation of rice straw with tree fodder rather than expensive concentrate may be acceptable when feeding working oxen although both diets are likely to be deficient in RDN.

The effects of treating adult red deer hinds nutritional demands to coincide better with and stags with exogenous melatonin on the food production on improved pastures. One calving season in hinds were evaluated in a 2 such method has been the administration of × 2 factorial experiment. Treated stags were implanted with melatonin monthly beginning in December and hinds post calving in January, Melatonin advanced the timing of rutting behaviour in both treated stags. Calving date was significantly influenced by melatonin treatment of hinds (a mean 10-day advancement; P < 0·01) or stags (12-day advancement; P < 0·001). The interaction of hind and stag treatments was not significant, however treatment of both sexes resulted in the greatest advancement in mean calving date (21 days; P < 0·001). These results indicate that treatment of red deer hinds or stags with exogenous melatonin can result in an earlier calving season and suggest seasonally advanced stags can stimulate earlier breeding activity in hinds.

Three steers cannulated in the rumen and abomasum were given a diet of wheat straw, chopped and soaked in sodium hydroxide and then washed to pH less than 8. The straw was sprayed with sucrose, urea and minerals. The diet was free of digestible protein and given at 1·7 to 4·1 kg/day. Microbial protein flowing to the omasum was measured by 15N. By difference, the flow of endogenous protein nitrogen to the omasum was found to be 2·2 g/kg dry-matter intake. The flow of endogenous protein nitrogen to the abomasum was 3·3 to 9·4 g/kg dry-matter intake, and it decreased with increasing food intake.

One hundred and five Holstein cattle, with a mean body weight of 668 kg, were superovulated using a total dose of 18 mg FSH. Five animals did not have corpora lutea (CL). No ova or embryos were recovered from 12 of the 100 animals which had CL. A total of 810 ova/embryos were collected from the remaining 88 animals and 432 of these were of transferable quality. The mean (range) measurements for subcutaneous fat deposition in samples taken at slaughter from the back, rump and ventral abdominal wall were 14 mm (3 to 34), 7 mm (0·7 to 33) and 7 mm (0·8 to 32), respectively. The number of transferable embryos and fertilized ova decreased as fat levels increased, but the differences between the groups were not significant (P > 0·05). There was a positive relationship between the number of CL and (a) the number of fertilized ova, and (b) the number of transferable embryos (r = 0·53, P < 0·001 and r = 0·48, P < 0·001). The correlation between the number of fertilized embryos and the number of transferable embryos was r = 0·91, P < 0·001.

The Effect of the Plane of Nutrition on the Optimum Dietary Amino Acid Pattern for Growing Pigs

T. C. Wang and M. F. Fuller

Volume 50, Part 1, page 157

FIG. 1 — The letters A and C on diagram should be reversed