- Production and reproduction potential of Namaqua Afrikaner sheep
|Last update: April 7, 2011 01:53:46 PM|
PRODUCTION AND REPRODUCTION POTENTIAL OF NAMAQUA AFRIKANER SHEEP
MA Snyman*, J.J. Olivier & W.J. Olivier
Grootfontein Agricultural Development Institute, Middelburg, 5900
Carnarvon Experimental Station, Carnarvon, 8925
The Namaqua Afrikaner is one of the indigenous sheep breeds in South Africa, descending from the Hottentot's fat-tailed sheep. These fat-tailed sheep were kept in the north-western part of South Africa where extreme temperatures and low and erratic rainfall are considered to be normal. Two Namaqua Afrikaner flocks of approximately 100 ewes each are maintained by the Department of Agriculture, one at the Carnarvon Experimental Station in the North-western Karoo and the second at the Karakul Experimental Station near Upington in the Northern Cape. The latter was originally kept at the Tarka Conservation Area near Hofmeyr in the North-eastern Karoo from 1985 to 1991, and the data used in this study were collected during that period. The ewe flock at Carnarvon is mated annually during autumn, while a free mating system was used at Tarka.
The calculation of growth parameters was done on data of 1113 lambs born from 1982 to 1991 in the Carnarvon flock. The mean of the production traits for rams and ewes respectively was : birth weight (4.55 ± 0.03kg, 4.27 ± 0.03kg); 100-day weaning weight (26.09 ± 0.17kg, 24.74 ± 0.18kg); average daily gain from birth to 100 days (215.44 ± 1.61g/day, 204.75 ± 1.72g/day); 8-month body weight (38.13 ± 0.18kg, 35.62 ± 0.20kg); 12-month body weight (51.90 ± 0.22kg, 43.95 ± 0.23kg); average daily gain from 100 days to 12 months (101.93 ± 0.73g/day, 75.74 ± 0.78g/day) and 18-month body weight (58.71 ± 0.25kg, 50.40 ± 0.29kg).
When comparing the pre-weaning growth of Namaqua Afrikaner lambs to those of Afrino and Dorper lambs run under similar conditions, it is evident that the Namaqua lambs compare favourably with the other breeds in terms of weaning weight and average daily gain from birth to weaning.
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. During the drought of 1994/1995, 31 Namaqua ram lambs and 42 Dorper ram lambs were slaughtered as soon as they reached a live body weight of approximately 42 kg. The purpose of this study was to evaluate the carcass quality of Namaqua Afrikaner lambs by comparing it to those of Dorper lambs. 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 following results were obtained for Namaqua Afrikaner and Dorper ram lambs respectively (in those traits followed by an * significant differences (P<0.01) were observed between the two breeds) : age at slaughter (301.88 ± 3.49 days and 293.63 ± 3.63 days); average daily gain from birth to slaughter age (127.77 ± 1.34 g/day and 131.35 ± 1.40 g/day); carcass weight (19.11 ± 0.23 kg and 18.48 ± 0.23 kg); dressing percentage* (51.90 ± 0.57 % and 48.51 ± 0.59 %); b1-measurement* (39.53 ± 0.23 cm and 35.06 ± 0.24 cm); b2-measurement* (52.47 ± 0.27 cm and 47.90 ± 0.28 cm); leg circumference* (65.52 ± 0.28 cm and 69.15 ± 0.29 cm); carcass length* (111.06 ± 0.43 cm and 105.43 ± 0.45 cm); v1* (13.94 ± 0.76 mm and 7.41 ± 0.80 mm); v2* (11.43 ± 0.64 mm and 5.29 ± 0.67 mm); v3* (9.57 ± 0.55 mm and 5.62 ± 0.57 mm); v4 (2.50 ± 0.25 mm and 2.47 ± 0.26 mm); v5* (0.75 ± 0.09 mm and 1.08 ± 0.09 mm); fat distribution over the eye muscle* (2.19 ± 0.12 and 3.60 ± 0.12); conformation score* (1.93 ± 0.44 and 5.88 ± 0.46); abdominal cavity fat score (4.58 ± 0.17 and 4.50 ± 0.18). 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 Namaqua Afrikaner lambs have a higher dressing percentage than Dorper lambs and their carcasses are longer with more fat in the posterior parts and less fat in the anterior parts. 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.
A conception rate of 85.95 ± 2.04% and fecundity of 156.43 ± 1.52% were recorded for the Carnarvon Namaqua Afrikaner flock. The survival rate from birth to weaning was 91.37 ± 0.75%, while 120.79 ± 3.77 lambs were weaned per 100 ewes mated. The Carnarvon Namaqua Afrikaner ewes weaned on average 37.45 ± 0.74 kg lamb per ewe per year, which compares favourably to that of Afrino and Dorper ewes.
The average age at first lambing in the Tarka flock was 16.5 months at an average body weight of 45.4kg. The average mating weight of adult ewes was 49.1kg. Over a period of seven years the average lambing interval for all ewes was 274 days.
In respect of production parameters, the Namaqua Afrikaner compares favourably with other South African sheep breeds. This breed is very hardy and prolific, as is evident from the relatively high reproductive performance recorded under extensive conditions. From these results it is evident that Namaqua Afrikaner ewes can be mated successfully at an early age, as well as throughout the year.
From these results it is evident that Namaqua Afrikaner sheep compares favourably with other breeds in terms of growth rate and reproduction performance. However, due to a consumer resistance against fat-tailed carcasses, the breed can not compete with other non fat-tailed breeds on the commercial mutton market. It is therefore essential that new and unique markets should be developed for the products of this breed. In a study in which the tanning qualities of Namaqua Afrikaner skins was investigated, it was concluded that these skins produce excellent garment leather.
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