The objective of this study was to determine whether injections
of Cloprostenol (PGF2 αanalog) in low libido Holstein bulls can improve
seminal characteristics and libido. Ten low libido Iranian Holstein bulls
were randomly assigned to two groups and received; (1) 250 μg of
Cloprostenol (n = 5) or (2) 2 mL of saline (n = 5) 30 min prior to collection
of semen 2 days per week for 2 months. Reaction time was significantly
decreased in treatment group. Duration of ejaculation was significantly
increased in treatment group. Semen volume and sperm concentration were
greater in treated bulls in compare with controls. The percentage of morphologically
normal sperm cells, percentage of live sperm cells, motile sperm cells
and post-thaw motile sperm cells were not affected by treatment. Plasma
testosterone concentrations were increased approximately two fold after
Cloprostenol injection. Overall, injection of Cloprostenol at this dosage
and frequency increased libido, semen volume, sperm concentration and
plasma testosterone concentration in low libido Holstein bulls.
R. Masoumi, A. Towhidi, A. Nejati Javaremi, H. Nabizadeh and M. Zhandi, 2008. Cloprostenol Injection Improves Reproductive Characteristics in Low Libido Iranian Holstein Bulls. Pakistan Journal of Biological Sciences, 11: 1027-1031.