EVALUATION OF GENETIC RESISTANCE TO HAEMONCHUS CONTORTUS INFECTION IN PAKISTANI SHEEP BREEDS

This study was conducted on four sheep breeds, Karakul, Kajli, Thalli and Kachhi for their natural resistance against Haemonchus contortus. After deworming, 13 animals of each breed were ingested with doses of 5000 L3 of Haemonchus contortus and then evaluation of each was made on the basis of fecal egg count (FEC), body weight, FAMACHA score and packed cell volume (PCV) at different days of interval. Out of four sheep breeds, Thalli sheep showed significant decrease (P< 0.05) in fecal egg count, higher PCV and less anemic score of FAMACHA thus presented greater resistance against Haemonchus contortus whereas Karakul, Kajli and Kachhi were seen susceptible to the infection. It was concluded that Thalli sheep have greater genetic tendency to resist against the Haemonchus contortus infestation and this breed could be kept and bred from the economic point of view.