Comparison of Red Maasai and Dorper sheep for resistance to gastro-intestinal nematode parasites: Productivity and efficiency in a humid and a semi-arid environment in Kenya

Red Maasai [Masai] and Dorper sheep were evaluated for their resistance to gastrointestinal nematode parasites (predominantly Haemonchus contortus), productivity and efficiency in experiments undertaken at the Kenyan coast (humid environment) and the Kenya highlands (semiarid environment). It was shown that Red Maasai sheep were more resistant and tolerant to endoparasite infections than Dorper sheep in both environments. There were important breed by environment interactions for flock productivity and efficiency, with the Red Maasai sheep being about 5-fold more efficient than Dorper sheep in the humid environment, while in the semiarid environment there was no significant breed difference in efficiency.