Premium lamb production of South African sheep breed types under feedlot conditions

An increasing number of producers opt to finish their lambs in on-farm feedlots. Therefore, detailed production information is required to implement precision finishing of lambs of different genotypes. Precision finishing monitors growth, feed intake and efficiency to optimize management. In this study, feedlot production characteristics of Dohne Merino, Dormer, Dorper, Meatmaster, Merino, Namaqua Afrikaner, and South African Mutton Merino (SAMM) lambs were evaluated. The lambs were reared in a feedlot and fed a diet with 10.41 MJ metabolizable energy (ME)/kg feed and 19.06% crude protein. Feed intake and body weight were recorded weekly from an initial weight of 30 kg until they had the subcutaneous fat cover needed to produce an A2 carcass. Subcutaneous fat was measured on the Longissimus lumborum muscle with an ultrasound scanner. Dorper, Meatmaster and Namaqua Afrikaner had the shortest rearing periods in the feedlot, and were market ready at a lower live weight (P <0.05). As a result, these lambs consumed less feed in the feedlot. Namaqua Afrikaner and Merino lambs were least efficient: 7.08 and 5.63 kg feed/kg gain, respectively. Dohne Merino, Dormer, Dorper, and Meatmaster rams and Dorper ewes were more efficient; approximately 3.58 kg feed/kg gain. Dohne Merino and Dormer rams had the highest growth rates: approximately 465 g/day. The end weights described in this study could be used as an indication for producers of the ideal slaughter weights for breeds of different maturity types.Keywords: average daily gain, fat deposition, feed efficiency, rearing period

The Current Status of Indigenous Ovine Genetic Resources in Southern Africa and Future Sustainable Utilisation to Improve Livelihoods

Indigenous sheep play an important role in the livelihoods of communal farmers in the Southern Africa Development Community (SADC), and this underlines the need to curb the genetic erosion of these valuable resources. This contribution reports that the phenotypic performance and genetics gains of institutional and commercial sheep in Southern Africa are well recorded. In contrast, there is a dearth of knowledge as far as the performance and genetic gains of indigenous ovine genetic resources utilized by smallholder farmers are concerned. High levels of genetic diversity have been observed in exotic breeds, whereas low levels of genetic diversity were found in the Zulu and Namaqua Afrikaner breeds. Phenotypic measurements for indigenous resources include linear measurements indicative of size and reproduction for Zulu sheep. Lamb survival, reproduction and resistance to ticks of the indigenous, fat-tailed Namaqua Afrikaner sheep, as well as growth and reproduction have also been recorded for Sabi and Landim sheep. This review discusses ways to sustainably utilize ovine genetic resources, which includes the suggested implementation of structured breeding and conservation programs, marketing, improving feed resources, health and diseases, as well as gender and age issues. Clearly, there is ample room for further research and development as far as the performance and improvement of African indigenous sheep are concerned.