Description    Clover (TRIFOLIUM)and Alfalfa (MEDICAGO SATIVA) contain phytoestrogens that might cause temporary infertility in ewes grazing at the time of mating or permanent infertility if there is a long history of grazing. Affected ewes fail to cycle and lambing is decreased. Enlarged teats and lactation have been reported in affected rams and wethers. A syndrome of dystocia has also been seen; high levels of dystocia with lambs born dead continued up to 6 months after ewes were removed from the pasture. A similar syndrome was reported in cattle.
Species   Bovine, Ovine
Signs   Abnormal length of estrus period, Abortion or weak newborns, Anestrus, Female infertility, Galactorrhea, inappropriate milk production, Swelling mass, vulva, clitoris
References   Driehuis F. Silage review: Animal and human health risks from silage. J Dairy Sci 2018;101:4093 [Web Reference]
Hashem NM. Effects of Trifolium alexandrinum phytoestrogens on oestrous behaviour, ovarian activity and reproductive performance of ewes during the non-breeding season. Anim Reprod Sci 2018;Mar [Web Reference]
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