J. B. Owen

The effect of dietary energy content on the voluntary intake of pigs.

1. An experiment to investigate the effect of dietary energy concentration on the voluntary intake and growth of pigs from 27·2 to 118·0 kg. (60 to 260 lb.) live-weight is described and the results discussed. 2. From 27·2 to 50·0 kg. live-weight energy intake was substantially restricted and growth retarded by diets of low energy concentration but from 50·0 to 118·0 kg. there was little difference between diets in either energy intake or growth because daily food intake of the low energy diets was increased. 3. Effects of diet on carcass quality as measured by full dissection were small except that killing-out percentage was lower on one of the low energy diets. 4. It is concluded that limited differences in the energy concentration and palatability of ingredients are unimportant in formulating pelleted diets for self-fed pigs.

The effects of varying the quantity and distribution of liquid feed in lambs reared artificially.

The research has been conducted to evaluate the nutrition’s characteristic and degradation of rice straw fermented xa0with lignolitic inokulum in different incubation time.xa0 Rice straw fermentation with lignolitik isolates increase the dry matter and crude protein content compare with dried fermented rice straw. On the other hand, fermentation decrease organic matter, crude fiber, and cellulose contents. The decreasing of OM, CF, and cellulose were lower than lignin. The fermentation with lignolitik inoculum increase the value of DM and OM degradation of rice straw in parameterxa0 non-soluble water fraction but degradable potentially(b), potensial of degradation (a+b) dan degradation time (c) BK dan BO but non significant to parameter water soluble fractions (a).xa0 Fermentation with lignolitik inoculum increase the nutritive value and degradation rice strwa and the best treatment was combination of TLiD danxa0 BOpR inoculums in three days incubation. (Animal Production 11(1): 1-7 (2009) Key Words : rice straw, rice straw fermented, lignolitik, lignin biodegradation, nutrition

The effect of food restriction on subsequent voluntary intake of pigs.

A total of 64 nine-week-old pigs were used in two experiments to study the influence on feed intake, growth and carcass quality of dietary restriction at various ages or live weights. Two diets of different energy content were given throughout each experiment, which was divided into four periods on either an age or weight basis. Feed was restricted or offered ad libitum during each of the first three periods, all pigs being fed ad libitum during the last period. Compensatory intake following a period of feed restriction occurred at most stages of growth but was most marked in the early stages. Compensation when it occurred took several weeks to develop fully and persisted for some time, often after an intervening period of ad libitum feeding. Increased gains resulted from increased intake although some of the early compensatory gains could not be fully explained by increased intake. There were few appreciable differences between the pigs on the highand those on the low-energy diets. However, in the early stages the latter did not show the same response in intake following restriction as did the former (but in experiment I the latter were considerably lighter). No effects on carcass quality were demonstrated under the conditions of these experiments.

The intensive rearing of lambs 1. Some factors affecting performance in the liquid feeding period

1. Investigations into possible ways of rearing artificially the lambs surplus to the ewes capacity are described and the results discussed. 2. A ewe-milk replacer with a high fat content was used from 2 days of age until weaning at 11.4 kg live weight. Two levels of milk feeding, restricted and ad libitum , were given in the second year. Significant differences were observed in live weight gain per day, milk consumption per kg live weight gain and solid food intake prior to weaning. Live weight gain and solid food intake in the period immediately after weaning also differed markedly. Sex and birth weight had little effect on performance. 3. Food costs were lower on the restricted level of milk feeding than on the ad libitum level.

Anorexigenic substances and voluntary food intake in the pig

The urine of pigs contains a substance with an anorexigenic effect when injected into pigs or rats. When injected into rats or pigs on ad libitum feeding a urine extract caused a reduction in food intake only when the extract had been obtained from the urine of satiated pigs, and not from hungry pigs. The pig urinary anorexigen there-fore appears to be similar in nature to the anorexigen extracted from rat urine. Like rat urinary anorexigen, its anorexigenic effect is largely dose dependent and it is soluble in distilled water. Rats injected with plasma from satiated pigs showed an anorexigenic reaction but injection of plasma from hungry pigs had no effect on food intake. The possible role of these anorexigenic substances in the control of voluntary food intake in the pig is discussed.

Factors affecting the cessation of oestrous activity in ewes

In the first experiment, 10 ewes (¼ Finnish Landrace: ¾ Clun Forest) were maintained under natural daylength conditions and 10 were exposed to a constant daylength of 8 hr from 22 December until 1 June. No difference was demonstrated between treatments in dates of cessation of oestrous activity. It was concluded that oestrous activity will eventually cease, whether or not daylength increases after the shortest day. In the second experiment, 40 similar ewes were mated at first oestrus of the natural breeding season (mean 7 September) and lambed in January. Twenty ewes suckled lambs and 20 had lambs removed within 24 hr of birth. No sucked ewes showed oestrus before the end of the breeding season, but 9 non-sucked ewes showed oestrus at a mean interval of 37·5 days after lambing and 4 of these subsequently lambed. Suckling appeared to inhibit oestrous activity and conception in ewes at this time of year.