Effect of Lamb Gender on Susceptibility to Natural Nematode Parasite (in) Infection Scottish Black Face Lambs

The aim of the present study was to evaluate the role of lamb gender on susceptibility to natural nematode infection. For this purpose, the study was conducted on a total number of 758 straight bred Scottish Black face lambs. The lambs were synchronized born in a period of April -May and weaned at 4-month of age. The study protocol was designed to assess fecal egg count (FEC) using Modified McMaster technique in a period of three consecutive months (August - October) for three successive years (2001-2003). The average mean number of lambs used in Augusts was 337 castrated males and 341 females, 339 castrated males and 336 females for Septembers and 354 castrated males and 348 females for Octobers. The results showed that the fecal egg counts in male were consistently higher than female at 6-months of age only (p<0.05). The distribution of transformed fecal egg counts in male and female lambs of each month over three years revealed that the majority of the lambs had relatively few egg counts and the variations in both genders varies among years. The results indicated that gender and time are determinants of faecal egg counts in Scottish Blackface lambs naturally infected with gastrointestinal nematodes.