Racial susceptibility of sheep to gastrointestinal helminths

Abstract

The objective was to compare the susceptibility of sheep breeds Lacaune, Bergamacia, Santa Ines and animals without defined breed (AWDB) kept confined to gastrointestinal helminths. The design used was a randomized block design being considered treatment the breeds. For research, the animals kept at pasture, were exposed to natural infection and kept from March to September 2008. A month before the start of the experiment, all animals were dewormed and confined. The anthelmintic used contained the active ingredient Moxidectin (0.2 mg/kg, Cydectin®, Fort Dodge, Brazil). Fecal examinations were performed twice a week and the animals with fecal egg count (FEC) over 4000 were dewormed. The mean variations of fecal egg count for the breed studied were: Lacaune 700-2600, Bergamacia 100-300, Santa Ines 61-200 and Natives 63-200. The average count of the sheep Lacaune FEC was significantly higher (p < 0.001) than the other breeds, while the FEC of animals Bergamacia, Santa Ines and Native were not statistically different (p > 0.05) among themselves. In coprologic tests, there was no difference between the percentage of helminths between the breeds, being identified the following genera: Haemonchus (70%), Trichostrongylus (20%), Cooperia (7%) and Oesophagostomum (3%). When analyzed the degree of susceptible breeds.