The effect of red clover pasture on the reproductive tract of ram lambs

Abstract

Fine-wool Merino ram lambs, weaned at c. 3 months of age, were grazed on either red clover (Trifolium pratense L.) or grass-dominant pastures.

Red clover did not retard puberty, and at c. 6 months of age the lambs showed no significant effect of clover on liveweight, weight of testes, and epididymides or the number of epididymal sperm. At 12 months of age the body weight, weight of testes, and epididymides and epididymal sperm numbers were all significantly greater on the red clover pasture.

A bioassay made when the animals were 9 months old indicated that the effective intake of oestrogenic substances obtained from grazing red clover was greater than the equivalent of 15 µg stilboestrol dipropionate per day given intramuscularly.