Ten Friezian cows at late stage of gestation were intramuscularly injected with 100 mg of selenium as sodium selenite at a rate of two doses with one week in-between. Seven pregnant animals were left with­out treatment as controls. Weight of their calves at birth and every week for 15 week were recorded, and blood samples on 1,10, 20, 30 & 40 days post-natal were taken for hormonal analysis. Selenium supple­mentation improved the live body weight of calves with a mean 10.7 Kg extra gain and a mean 13..74% faster growth rate at the end of experi­mental period. The overall mean of weight gain and relative growth rate of calves per week were significantly increased (4.24 vs. 3.64 kg and 8.42 vs. 7.84%, respectively). Serum growth hormone (total, free and binding forms), prolactin (total and binding forms) and thyrotrophic hor­mone of one day old calves were significantly increased after dam sup­plementation. Furthermore, selenium exerted its favourable effect on growth hormone and thyrotrophic hormone up to 40 days post-natal.