F. W. H. Elsley

The effect of plane of nutrition on the carcasses of pigs and lambs when variations in fat content are excluded

1. From a review of the literature it has been shown that there are two opposing views regarding the best method of interpreting growth data, which arise from conflicting opinions as to the role of fat deposition in the growth of the animal. 2. Data of McMeekan and Palsson and Verges have been re-analysed and their own results are compared with results obtained when the effects of variation in fat content are eliminated. 3. No evidence has been found of any effect of plane of nutrition on the total weights of bone and muscle relative to the weight of bone plus muscle together. 4. The weight of bone plus muscle in the head and neck was increased relative to the total weight of bone plus muscle during periods of restricted nutrition. Apart from this there was no clear evidence of a relationship between the order of maturity of the joints and their relative retardation of development. 5. Huxleys allometry equation was found appropriate for standardising the measurements, and the exponent was taken as a numerical expression of the relative maturity of each tissue or part.

The effects of level of feeding of sows during pregnancy. I. Reproductive performance

1. Twelve sets of 3 litter-sister Large White gilts were mated at first oestrus after reaching 250 lb. live-weight and given daily during 3 successive pregnancies either 6 lb. (A), 3 lb. (B) or 3 lb. for 76 days then 6 lb. until parturition (C) of the same meal mixture. During an 8-week lactation all were given 4 lb. meal plus 0·8 lb. per piglet suckled. 2. There was a significant linear increase in numbers born with successive parities (P 3. Post-natal litter performance was poor for all groups, probably because of the presence of E. coli , but there was no evidence of treatment effects other than on 3-week weight of third litters, which was significantly greater in Group C than in A or B (P

The effect of pattern of food intake in pregnancy upon sow productivity.

Seven research and teaching centres have co-operated in an experiment involving 154 sows. The experiment compared the effect of feeding four different patterns of feed intake during pregnancy upon reproductive performance of sows. In each case approximately 220 kg of feed were given during each gestation according to four patterns of intake designated Constant (C), Low-High (L-H), High-Low (H-L) and High-Low-High (H-L-H). During lactation all animals were given a daily ration of 3·7 kg of feed for litters of five pigs or less, and 0·4 kg for each additional piglet. Wherever possible the sows remained on the same nutritional regimes for three parities. Although the pattern of feed intake slightly affected the live-weight changes of the sows during the course of pregnancy, the treatments had no significant effects on overall change in weight of the sows in pregnancy or in lactation in any of the three parities. The live weights of the sows at the end of the third parity were very similar for all treatment groups. The patterns of feed intake had no appreciable or significant effect on the numbers of pigs born, their average weight at birth or upon the numbers of pigs which survived to weaning at 6 weeks or their live weight. The health and breeding regularity of the sows were also unaffected by the treatments. There were differences between the centres in many of the variables which were compared, but there was no evidence of any important centre × treatment interactions. It is concluded that, at the levels of intake given in pregnancy and lactation in this experiment, there are no beneficial or detrimental effects of changing the pattern of intake during pregnancy.

Moist barley for growing pigs: some effects of storage method and processing.

Forty-eight pigs were used to compare the feeding value of barley which had been stored dry, and then hammer-milled, with that of barley stored moist, either anaerobically or treated with 1·3% propionic acid, and then rolled. The pigs were fed from 30 kg live weight for a period of 11 weeks and during this period all consumed the same allowance of dry matter. The growth rate and feed conversion ratio of the pigs given the rolled moist barley were significantly poorer than those of others given dry milled or acid treated rolled barley. There were no treatment differences in carcass attributes. Microbiological counts made throughout the experiment showed that there was no significant fungal or bacterial development on the acid treated barley. Similar numbers of bacteria were present on the dry barley as on the moist, but the fungal count for the moist grain was always at least 500 times higher than that of the corresponding dry sample. The dominant organisms were identified. In a further experiment the apparent digestibility of dry matter and nitrogen of diets containing dry, moist or propionic acid treated barley, processed either by milling or rolling, were determined. The highest values were obtained for dry barley. Acid treated moist barley had lower values than moist barley. The method of processing did not affect the apparent digestibility of the dry matter, but that of the N was significantly lower for the rolled barleys.

The influence of dietary protein intake during lactation on the reproductive performance of sows

1. Forty-five Large White gilts were given 2·20 kg daily of a diet containing 14·0% crude protein during three successive pregnancies. During a 6-week lactation they received 5·30 kg daily of one of three diets containing 19·0% (HP), 16·5% (MP) or 14·0% (LP) crude protein. 2. Daily milk yield was estimated on the 10th, 20th, 30th and 40th day of lactation. Milk samples were obtained from the same sows for the determination of protein, fat, lactose and total solids on the 11th, 21st, 31st and 41st day. 3. One sow and litter from each treatment in each lactation was placed in metabolism cages during lactation and estimates of nitrogen and dry matter excretion obtained. 4. As the concentration of protein in the diet decreased the average 42-day gain in litter weight from birth increased significantly in the first lactation. This trend continued in the second lactation although it was not significant but did not appear in the third. 5. There was no marked difference in daily milk yield between treatment groups. 6. There was a significantly greater loss of live weight by the sows on the lower levels of protein in the first lactation. These differences were not significant in the second and third lactations.