Relative resistance of Menz and Washera sheep breeds to artificial infection with Haemonchus contortus in the highlands of Ethiopia

摘要: The aim of this study was to evaluate the relative resistance Menz and Washera sheep breeds artificial infection with Haemonchus contortus. challenge trial conducted at Debre Berhan Agricultural Research Center in Ethiopia. A total 39 (Menz = 21, Washera = 18) lambs about 6 months old were used for trial. All initially treated against internal parasite using albendazole Fasinex free them from parasites kept indoors. H. contortus third-stage larvae (L3) prepared according standard procedure adult female collected abattoirs recovered Baerman technique. Approximately 5000 infective inoculated experimental 5 weeks after deworming. Fecal egg count (FEC), packed cell volume (PCV), FAffa MAlan CHArt (FAMACHA) score, lamb body weight, survival recorded 28, 35, 42 days challenge. Breed effect not significant (P > 0.05), whereas time measurement interaction breed had (P < 0.05) effects on FEC PCV. At 28 days challenge, lower than sheep, days 35 42, lambs. PCV decreased significantly throughout post-challenge period. Despite their burden, able maintain live weight during Chi-square tests differences any (28, challenge). Lower delayed rise would allow delaying anthelmintic treatment. In addition weights period, both exhibited substantial variability FEC, suggesting opportunity consider selection program.