Nutritional management during fetal and postnatal life, and the influence on testicular stereology and Sertoli cell numbers in Corriedale ram lambs

The aim of the experiment was to determine whether supplementation of the l amb-ewe unit during intra-uterine and postnatal life affects testicular ste reology, particularly Sertoli cell numbers, in 120 pregnant Corriedale ewes grazed either native pastures (control group) or improved pastures + grain supplement (treated group). Ewes bearing single ram lambs were maintained under the same feeding regime until lambs were castrated (99 days of age). Body weight, testosterone and FSH blood serum levels were recorded at 45, 7 5 and 99 days of age. Body weight was higher (P < 0.01) in the treated grou p from birth on. Serum testosterone values did not differ between groups. S erum FSH values tended to differ at 45 days of age (P < 0.06). Testicular w eight and testes histology showed earlier pubertal development and a tenden cy for higher Sertoli cell numbers in the treated (supplemented) group. Thi s tendency may indicate that extensively reared lambs supplemented during f etal and postnatal life have higher testicular growth and sperm production in later life. (C) 2001 Elsevier Science B.V. All rights reserved.