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Growth rate effects on some offal components of sheep

Published online by Cambridge University Press:  27 March 2009

D. M. Murray
Affiliation:
School of Wool and Pastoral Sciences, University of New South Wales, Kensington, New South Wales, Australia
Olga Slezacek
Affiliation:
Hawkesbury Agricultural College, Richmond, New South Wales, Australia

Summary

The effect of three different growth rates from 15 to 40 kg live weight on some offal components of lambs was studied. The treatments were: high (H) ad-libitum feed intake, low (L) restricted feed intake and high-maintenance-high (HMH) ad-libitum feed intake from 15 to 25 kg followed by a 50-day period of weight stasis, which was followed by ad-libitum feeding. In each treatment, two animals were killed at 25, 30 and 35 kg and three animals at 40 kg. Analyses of covariance were used to compare linear regression equations representing results from each treatment using the logarithmic transformation of the allometric equation, y = axb.

Differences between treatments were found for the weight of certain non-alimentary tract offals including the liver (H, HMH > L), kidney (H, HMH > L), skin (H, HMH > L) and hind-hooves (H < HMH, L). The slope of the regression for the heart, liver, kidney, and the combined trachea and lungs was greater in the HMH, than in the H, treatment. These differences in slope were attributed to a decrease in weight of each component in the HMH animals during weight stasis except for the lungs and trachea, where the greater slope was due to an increased weight of this component in the HMH animals killed at 40 kg.

Fat-trimmed weights of the omasum, abomasum, small intestine and large intestine were greater in both the H and HMH animals than the L animals. The weights both of the rumen-reticulum and total alimentary tract (TAT) were less at 25 kg in HMH animals than in either H or L animals although, overall, the weight of TAT was greater in the H and HMH treatments than in the L treatment. A comparison of data for the H and HMH treatments showed that weight stasis decreased the weight of all separate parts of the alimentary tract, particularly the rumen-reticulum and the small intestine.

Chemical analyses (water, N × 6·25 and ether extract) were conducted on four alimentary tract components, namely the combined rumen-reticulum and omasum (RRO) abomasum, small intestine and large intestine. The results of these analyses showed that composition was similar in the three treatments despite treatment effects on the weight of some parts of the tract.

Chemical data were pooled across treatments to compare composition of the different alimentary tract components. This analysis showed that chemical composition was different both for all parts of the tract and for all chemical components with two exceptions. There was no difference between the RRO and small intestine for either water or ether extract.

Common regression equations are presented for each component of the alimentary tract relating the weights of three chemical components to tissue weight. Water and protein content were more closely related to tissue weight than was ether extract. It is suggested that both water and protein content may show a sufficiently close relationship to tissue weight whereby they may be predicted from a knowledge of the latter, particularly the RRO and small intestine.

There were no differences between treatments in the weights of fat trimmed from the alimentary tract despite treatment effects on either the weight of some parts of the tract or other offals.

Apart from a greater weight of digesta in the small intestine in the H animals than in L animals relatively minor differences between treatments were found in the amounts of digesta in different parts of the tract.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1980

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References

Association of Official Agricultural Chemists (1955). Official Methods of Analysis, 8th ed.Washington: A.O.A.C.Google Scholar
Burton, J. H., Anderson, M. & Reid, J. T. (1974). Some biological aspects of partial starvation. The effect of weight loss and regrowth on body composition in sheep. British Journal of Nutrition 32, 515527.CrossRefGoogle ScholarPubMed
Dowling, D. F. (1955). The thiokness of cattle skin. Australian Journal of Agricultural Research 6, 776785.CrossRefGoogle Scholar
Drew, K. R. & Reid, J. T. (1975a). Compensatory growth in immature sheep. 1. The effect of weight loss and realimentation on the whole body composition. Journal of Agricultural Sciences, Cambridge 85, 193204.CrossRefGoogle Scholar
Drew, K. R. & Reid, J. T. (1975). Compensatory growth in immature sheep. 2. Some changes in the physical and chemical composition of sheep halfcarcass following feed restriction and realimentation. Journal of Agrinilturril Science., Cambridge 85, 205213.CrossRefGoogle Scholar
Fell, B. F., Campbell, R. M. & Boyne, R. (1964). Observations on the morphology and nitrogen content of the alimentary canal in breeding hill sheep. Research in Veterinary Science 5, 175185.CrossRefGoogle Scholar
Leche, T. F. (1973). Proportions of carcass and offal components of Jersey and Friesian bulls in relation to plane of nutrition. Australian Journal of Agricultural Research 24, 623631.CrossRefGoogle Scholar
Murray, D. M. & Slezacek, O. (1976). Growth rate and its effect on empty body weight, carcass weight and dissected carcass composition of sheep. Journal of Agricultural Science, Cambridge 87, 171179.CrossRefGoogle Scholar
Murray, D. M. & Slezacek, O. (1978). The effect of varying periods of maintenance of live weight on some body components of sheep. Proceedings of the Australian Society of Animal Production 12, 237.Google Scholar
Murray, D. M., Tulloh, N. M. & Winter, W. H. (1974). Effects of three different growth rates on empty body weight, carcass weight and disseoted carcass composition of cattle. Journal of Agricultural Science, Cambridge 82, 535547.CrossRefGoogle Scholar
Murray, D. M., Tulloh, N. M. & Winter, W. H. (1977). The effect of three different growth rates on some offal components of cattle. Journal of Agricultural Science, Cambridge 89, 119128.CrossRefGoogle Scholar
O'donovan, W. M. (1974). Developmental changes in the bodies of Dorper sheep. 4. Effect of rate of live body-mass gain and energy concentration of diet on body composition of weaned Dorper lambs. Rhodesian Journal of Agricultural Research 12, 113—125.Google Scholar
O'donovan, W. M. (1974). Developmental changes in the bodies of Dorper sheep. 5. Effects of feeding diets of different metabolizable energy concentration adlib., either from the start or after a period of growth restriction, on the body composition of weaned Dorper lambs. Rhodesian Journal of Agricultural Research 12, 127140.Google Scholar
Searle, T. W. & Graham, N. McC. (1975). Studies of weaner sheep during and after a period of weight stasis. 2. Body composition. Australian Journal of Agricultural Research 26, 355361.CrossRefGoogle Scholar
Slezacek, O. (1976). Growth rate and body composition of lambs. M.Sc. thesis, University of New South Wales.Google Scholar
Swan, H. & Lamming, G. E. (1967). Studies on the nutrition of ruminants. 2. The effect of level of crude fibre in maize-based rations on the carcass composition of Friesian steers. Animal Production 9, 203208.Google Scholar
Trowbridoe, P. F., Moulton, C. R. & Haigh, L. D. (1918). Effect of limited food supply on the growth of young beef animals. University of Missouri Agricultural Experiment Station Research Bulletin, no. 28.Google Scholar
Winter, W. H., Tulloh, N. M. & Murray, D. M. (1976). The effect of compensatory growth in sheep on empty body weight, carcass weight and the weights of some offals. Journal of Agricultural Science, Cambridge 87, 433441.CrossRefGoogle Scholar
Wodszicka, M. (1958). Studies on the thickness and chemical composition of the skin of sheep. 2. Variations during growth. New Zealand Journal of Agricultural Research 1, 592600.Google Scholar