Animal Industry Report

Extension Number

ASL R3050



Summary and Implications

Commercial pyrethroid pour-ons are commonly appliedin cow-calf operations to eliminate the potential for insectborne diseases and to improve productivity. However,recent literature has focused on potential negativereproductive effects in the bull after exposure to pyrethroids.While the female bovine has been primarily neglected fromthe debated pyrethroid concern on reproduction, literature inmice and rats have reported potential endocrine disruptionof sex steroids resulting from pyrethroid exposure, withpotential detrimental effects on female fertility. Theobjective was to study the effects of a commercialpyrethroid-based pour-on product, permethrin, onreproductive performance in superovulated beef heifers byassessing steroid biosynthesis and embryo quality. It washypothesized that exposure to pyrethroid pour-on at labeldose would cause minimal effects on embryoquantity/quality and steroidogenesis in the female bovine.Results from this study revealed pyrethroid-treated heifershad a tendency for reduced progesterone, but embryoquantity and quality were not affected compared to controls

Copyright Holder

Iowa State University