Effects of dietary gossypol in cottonseed meal on aspects of semen quality and sperm production in young braham bulls

Abstract

Young reproductively normal Brahman bulls were fed either a cottonseed meal supplement giving 8.2g free gossypol/day (n=4) or a soybean meal supplement (n=4) for 11 weeks to study effects upon semen characteristics and sperm production. Semen was collected weekly by electro-ejaculation and assessed for sperm motility and morphology (employing both brightfield and DIC microscopy). At trial completion, bulls were sacrificed and sperm production rates were estimated. Sperm motility differed between groups over the last 3 weeks of the trial. Normal sperm were less in treated bulls from week 5, with midpiece abnormalities differing from week 3. Treated bulls had lower sperm production rates at trial completion.