Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-29T01:40:24.450Z Has data issue: false hasContentIssue false

Effect of tail docking in Awassi lambs on metabolizable energy requirements and chemical composition of carcasses

Published online by Cambridge University Press:  18 August 2016

R. A. M. Al Jassim
Affiliation:
Jordan University of Science and Technology, PO Box 3030, Irbid, Jordan
G. Brown
Affiliation:
Biometrics Unit, CSIRO Mathematical and Information Sciences, PO Box 52, North Ryde, NSW 2113, Australia
E. D. Salman
Affiliation:
Jordan University of Science and Technology, PO Box 3030, Irbid, Jordan
A. Abodabos*
Affiliation:
Jordan University of Science and Technology, PO Box 3030, Irbid, Jordan
*
Department of Animal and Veterinary Sciences, Clemson, University Clemson, SC 29634, USA.
Get access

Abstract

The effect of tail docking on metabolizable energy requirements and carcass characteristics was studied using 80 weaned entire Awassi male lambs. Docking was performed within 3 days of birth and lambs were weaned at 90 days old. Docked and undocked lambs were randomly allocated to four groups, individually penned and offered different amounts of a pelleted concentrate diet. The pelleted diet was estimated to contain 11·8 MJ of metabolizable energy (ME) and 182 g of crude protein (CP) per kg dry matter (DM). Lambs on the high levels of intake were slaughtered at a target weight of approximately 45 kg. Other lambs were maintained on the diet for 149 days before being slaughtered. The right sides of all carcasses were cut into standardized commercial cuts then dissected into muscle, fat and bone. The soft tissue was pooled and analysed for DM, C P, ash and fat. Prediction of live-weight gain (LWG) and empty body gain for a given ME intake (MEI) was made using the growth and MEI data. MEI was expressed as MJ per kg metabolic body weight (M 0·75) per day. Tail docking had no effect (P > 0·05) on lamb growth from birth to weaning. During the post-weaning growth period, LWG and empty body gain were significantly higher (P < 0·05) for undocked lambs than docked lambs, at feeding levels between 0·31 and 0·52 MJ/kg M 0·75 per day and similar (P > 0·05) at high levels of intakes (between 0·74 and 1·1 MJ/ kg M 0·75 per day). Hot and cold carcass weights were similar (P > 0·05) for the two groups. Differences in empty body weight and fleece-free empty body weight were significant (P < 0·05) only for the 0·443 to 0·522 MJ/kg M 0·75 per day level of ME intake. Predicted ME requirements were higher for docked lambs for an estimated LWG between 0 and 100 g/day and lower for higher LWG (125 to 225 g/day). Docking had no effect (P > 0·05) on food conversion efficiency (FCE). Carcasses from docked lambs had significantly lower (P < 0·001) internal plus tail fat. Pooled soft tissue excluding tail fat, for the undocked lambs contained significantly more (P < 0·01) protein, less (P < 0·001) fat, higher (P < 0·01) moisture and similar (P > 0·05) ash content.

Type
Research Article
Copyright
Copyright © British Society of Animal Science 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Agricultural and Food Research Council. 1990. Technical Committee on Responses to Nutrients. Report no. 5. Nutritive requirements of ruminant animals: energy. Nutrition Abstracts and Reviews, Series B 60: 729804.Google Scholar
Al Jassim, R. A. M., Hassan, S. A. and Al-Ani, A. N. 1996. Metabolizable energy requirements for maintenance and growth of Awassi lambs. Small Ruminant Research 20: 239245.CrossRefGoogle Scholar
Alkass, J. E., Rashid, N. H., Ishak, M. A. and Talib, H. 1985. The combined effects of docking and castration on growth rate and carcass characteristics of Awassi lambs. World Review of Animal Production 11: 4952.Google Scholar
Association of Official Analytical Chemists. 1984. Official methods of analysis, 14th edition. Association of Official Analytical Chemists, Arlington, VA.Google Scholar
Aus-Meat., 1990. Sheep meat. In Handbook of Australian meat, fourth edition, pp. 173186. Australian Meat and Live-Stock Corporation.Google Scholar
Epstein, H. 1961. The development and body composition of docked and undocked fat-tailed Awassi lambs. Empire Journal of Experimental Agriculture 29: 110118.Google Scholar
Farhan, S. M. A., Al-Khalisi, I. J. and Hameed, M. A. 1969. Effect of docking on growth and fattening of Awassi lambs. Iraqi Journal of Agriculture Science 4: 5765.Google Scholar
Joubert, D. M. and Ueckermann, L. 1971. A note on the effect of docking on fat deposition in fat-tailed sheep. Animal Production 13: 191192.Google Scholar
Ministry of Agriculture, Fisheries and Food. 1987. Energy allowances and feeding systems for ruminants. Reference book 433, p. 15. Her Majesty’s Stationery Office, London.Google Scholar
O’Donovan, P.B., Ghadaki, M. B., Behesti, R. D., Saleh, B. A. and Rollinson, D. H. L. 1973. Performance and carcass composition of docked and control fat-tailed Kellakui lambs. Animal Production 16: 6776.Google Scholar
Shelton, M. 1990. Influence of docking fat-tail (Karakul) sheep on lamb production (technical note). Small Ruminant Research 3: 7376.Google Scholar
Shelton, M., Willingham, T., Thompson, P. and Roberts, E. M. 1991. Influence of docking and castration on growth and carcass traits of fat-tail Karakul, Rambouillet and crossbred lambs. Small Ruminant Research 4: 235243.CrossRefGoogle Scholar
Stuart, A. and Ord, J. K. 1991. Kendall’s advanced theory of statistics, fifth edition. Edward Arnold, London.Google Scholar