The lambing records of a mixed flock of Yankasa x Balami ewes, managed semi-intensively at the National vertinary Research Institute (NVRI) farm Vom, were evaluated within a 2 year period (January 1985 – December, 1986. A total of 106 lamblings made up of 61 males and 45 females were investigated. The lambs were grouped by sex, months and seasons of birth. The results showed that the average weight of the male lambs (2.93 ± 0.09kg) was significantly more (P