Effect of feeding pine needles on ovine reproduction.

Estrous cycles were not altered in 30 mature ewes fed pine needles 11 to 13 days prior to breeding. Pregnancy and lambing rates were not affected by the feeding of pine needles. An antiestrogenic effect of pine needles on the reproductive process in ewes was not clinically detectable. There was no indication of any toxic effects on ewes consuming a 37% pine needle diet.