Sheep show genetic resistance to endoparasites

Studies conducted by the International Livestock Centre for Africa (ILCA) in coastal Kenya indicate that the local Red Maasai sheep are more resistant to endoparasites than the introduced Dorper sheep breed. These studies also provide the first evidence of genetic variation in endoparasite resistance within African sheep breeds. Early results show that smallholders at the Kenya coast could double their lamb off-take if they used Red Maasai-cross animals instead of Dorpers. Dorper sheep, which originate in South Africa, have become popular in Kenya because they can grow faster and attain heavier body weights than local breeds of sheep. But while this may be true under the relatively favourable conditions of the Kenyan highlands, it does not necessarily hold true elsewhere. ILCA's studies in the subhumid coastal zone show that growth rates and body weights are similar in Dorper and Red Maasai. The Red Maasai-Dorper crosses are more productive than the Dorper itself because they have a better reproductive performance and lower mortality rates both of which may be linker to their greater resistance to endoparasites . The predominant endoparasite found in sheep and goats in both the coastal and highland areas of Kenya is the bloodsucking parasite Haemonchus contortus, which is one of the most pathogenic gastro-intestinal parasites. The ILCA research was based on results from a 100-ewe herd using Dorper, Dorper-Red Maasai crosses and backcrosses and has shown that smallholders who keep sheep in the subhumid coastal zone in Kenya should be encouraged to keep indicenous stock such as the Red Maasai or cross-brads with at least 50% Red Maasai blood. Using end oparasite-resistant Red Maasai sheep could double a farmer's annual lamb crop. The implications for the rest of Africa are significant: losses due to endoparasites will be reduced, use of expensive control chemicals will also be reduced and this in turn will reduce environmental contamination and the development of drug-resistant strains of endoparasites. Dr Leyden Baker ILCA PO Box 46847 Nairobi - KENYAStudies conducted by the International Livestock Centre for Africa (ILCA) in coastal Kenya indicate that the local Red Maasai sheep are more resistant to endoparasites than the introduced Dorper sheep breed. These studies also provide the first..