Influence of Genotype and Sex on Body Weight Evolution of Crossbred Lambs

A crossbreeding experiment was conducted to evaluate the growth performance of lambs from birth to five months, focusing on sex and genotype. The experiment involved three French meat breed rams and one R1 German Blackface (75%) x Tsigai (25%) ram with R1 crossbreed ewes of the same genotype (German Blackface 75% x Tsigai 25%). A total of 151 R1 crossbreed ewes were divided into four groups and mated with the following rams: group 1 with Berrichon du Cher, group 2 with Blanche du Massif Central, group 3 with Mouton Vendèen, and group 4, the control group, with R1 German Blackface x Tsigai (BFxTI). The study found that both genotype and sex significantly influenced the growth performance of the lambs. Male and female lambs from the group 4 were heavier at birth compared to lambs from group 3 (P< 0.001). At 28 days, significant differences (P< 0.001) were observed between females from group 4 and both males and females from group 1, as well as females from group 3. This trend continued at 56 days, the females from group 4 being heavier than both males and females from groups 1 and 3 (P< 0.001). At five months, males from group 1 had significantly higher body weights (P< 0.001) compared to females in group 4.