Last update: March 30, 2012 02:25:05 PM E-mail Print




JJ Olivier



The development of a white woolled mutton breed for the extensive sheep grazing areas of South Africa has been preceded by low wool prices and high meat prices in the late sixties and the inability of the Merino to produce a good slaughter lamb under extensive veld conditions. To exploit the high meat prices, Dorper, Van Rooy and Afrikaner rams have been used to produce slaughter lambs in extensive conditions, which, in turn, contaminated the wool with kemp and coloured fibres. In a memorandum submitted by the S A Agricultural Union, a request was addressed to the state to develop a white woolled mutton breed for the extensive sheep grazing areas. The requirements laid down for such a breed were that (a) it must be free of kemp and contain no coloured fibres; (b) it must be hardy and adapted to extensive sheep grazing areas; (c) it must. when crossed with the Merino, produce a good slaughter lamb at an early age.

In 1969, the development of such a breed was commenced when 8 different crossings were done on the Carnarvon Experimental Farm. The various breeds crossed with one another are indicated in Table 1.



In 1976, all the results achieved with the various crosses were analysed. In October/November all ewes were mated to 2% rams for six weeks and all groups were treated similarly. The eighth group (VM x RA) fell away because the Mutton Merino rams were incapable of serving the Afrikaner ewes.

Table 2 reflects the average reproduction of different crosses from 1971 to 1975. The fourth group (% VM x ¼ M x ¼ RA) according to Table 2, possessed the best reproductive characteristics. In this group, 72,6% ewes have been served per ewe mated, which was 1,9% better than the 70,7% of Group 5.



Not only the most ewes were served in Group 4, but it also produced the most multiple births, namely 26,4%. Together with the fact that lamb mortality at birth (6,8% ) and birth to weaning (4.14%) was not significantly higher than any of the other groups, its result was that the most lambs per mated ewe, namely 61,8%, were weaned in this group.

The average body mass from birth up to 18 months of rams and ewes born from 1972 to 1976 in the various groups are reflected in Table 3. Except in Group 6 (M x M) there was little difference in the birth masses of the various groups. At weaning age (corrected 100 days mass) the rams of Group 4 were the heaviest, namely 35,56 kg, while the ewes weighed 31,58 kg. This means that the daily mass gain of 0-100 days was 308 g in Group 4 rams and 269 g in Group 4 ewes. This mass gain was higher than the 281 g per day and 275 g per day of the rams and ewes respectively of Group 7 (D x D). At 12 months and 18 months age, Group 7 (D X D) on average, weighed more than Group 4, although the differences were not meaningful.



Table 4 reflects the wool characteristics of the various groups.



Group 6 (M x M) yielded the highest clean wool mass (2,57 kg) while few differences occurred between the clean wool masses of Groups 1 to 5. Increased variation in regard to the other wool characteristics occurred among the groups. Together with quantity, fibre thickness is the most important determining factors of the price of wool (thinner fibres, higher prices). If this is borne in mind, it appears from Table 4 that Group 6 (M x M) had the best wool characteristics with Groups 1, 2, 4 and 5 the second best choices.



If the requirements laid down by the S.A.A.U. for a white woolled mutton breed for extensive sheep grazing areas are borne in mind, it is evident from the foregoing that the cross existing of 25 % Merino: 25% Ronderib Afrikaner and 50% S A Mutton Merino has met these requirements the best. The group has weaned the most lambs, it had the best mass gains up to weaning age and together with Group 2 (¼D x ¼M x ½ MM)and Group 7 (D XD)it had the highest weight at 12 months and 18 months. Although the group did not possess the best wool characteristics, it produced 31% less wool than the Merino under similar conditions. The average fibre thickness was less than 27 micron, which is accepted by the NWGA as Merino type. This cross, also had no coloured fibres and it was kemp free. Only this group has been maintained since 1976 and is known as the Afrino.



Afrino Manual, Vol 1, 1982