Influence of $PGF_{2alpha}$ on semen quality and libido in Holstein bulls

Abstract

The aim of this study was to determine the ef ects of Cloprostenol ($PGF_{2alpha}$analogue) on semen quality andlibido in Holstein bulls. Ten low libido Iranian Holstein bulls were randomly allocated to 2 groups and received Clo- prostenol (n = 5) or saline (n = 5) 30 min prior to the semen collection 2 days per week for 2 months. Reaction timewas signii cantly decreased in the treatment group. Duration of ejaculation was signii cantly increased in the treatmentgroup. Semen volume and sperm concentration were higher in treated bulls when compared with controls. h e percent- age of morphologically normal sperm cells, percentage of live sperm cells, motile sperm cells, and post-thaw motilesperm cells were not af ected by the Clopostenol. Plasma testosterone concentrations were increased at er Cloprostenolinjection. It was concluded that injection of $PGF_{2alpha}$improved libido, semen quality, and plasma testosterone concentra- tion in low libido Holstein bulls.