Last update: November 22, 2010 11:33:00 AM E-mail Print

 

COMPARISON OF CARCASS CHARACTERISTICS OF NAMAQUA AFRIKANER AND DORPER LAMBS

 

1M.A. Snyman & M.J. Herselman, 2J.A.N. Cloete, 3M.L. Jonker

 

1Grootfontein Agricultural Development Institute, P/Bag X529, Middelburg, 5900, South Africa

2Carnarvon Experimental Station, P.O. Box 98, Carnarvon, 8925, South Africa

3Vaalharts Research Station, Private Bag X9, Jan Kempdorp, 8550, South Africa 

 


It is a fact that fat-tailed sheep carcasses are labelled at the abattoirs and prices of up to R 3-00 per kg less are paid for fat-tailed carcasses when compared to other non fat-tailed carcasses of the same fat grade. At the Departmental Experimental Station at Carnarvon, a Namaqua Afrikaner and a Dorper flock are run under similar management conditions. The lambs of these two flocks run together from weaning at the age of 100 days. The purpose of this study was to evaluate the carcass quality of Namaqua Afrikaner ram lambs by comparing it to those of Dorper ram lambs.

Thirty-one Namaqua ram lambs and 42 Dorper ram lambs born during August-September 1994 were slaughtered as soon as they reached a live body weight of approximately 42 kg. All lambs were slaughtered directly from the veld and received no supplementary feeding. It should be noted that the rainfall for the period August 1994 to July 1995 was 106 mm, compared to the average annual rainfall of 210 mm. This lead to relatively poor grazing conditions, as will be evident from the relatively high slaughter ages in both breeds. The same measurements as those taken in the National Lamb Carcass Competition were recorded on each carcass. The data were analysed with least-squares means procedures, and fixed effects for breed and rearing status, as well as a covariate for slaughter weight, were included in the model.

The following results were obtained for Namaqua Afrikaner and Dorper ram lambs respectively: age at slaughter  (302±3.5 days and 294±3.6 days); average daily gain from birth to slaughter age (127.8±1.3 g/day and 131.4±1.4 g/day); carcass weight (19.1±0.2 kg and 18.5±0.2 kg) and dressing percentage (51.9±0.6 % and 48.5±0.6 %).

The weight of the fat tails of the Namaqua Afrikaner lambs ranged from 0.8 kg to 3.0 kg, with an average of 1.8 kg. The results indicate that the carcasses of Namaqua Afrikaner lambs are longer with more fat in the posterior parts and less fat in the anterior parts than those of Dorper lambs. Dorper carcasses have a more square conformation, compared to the narrower carcasses of the Namaqua Afrikaner. This may in part explain the consumer resistance against fat-tailed carcasses, as the more expensive cuts are not as attractive as those of Dorper carcasses.

 

References

BRUWER, G.G., 1984. Objective evaluation of the carcass grading system for lambs and sheep in R.S.A. M.Sc. treatise, University of Stellenbosch, Stellenbosch, South Africa.

SNYMAN, M.A., HERSELMAN, M.J. & CLOETE, J.A.N.,  1996. Carcass characteristics of Namaqua Afrikaner lambs. Congress DAB-SASAS, Pilansberg, 1-4 October