The current study aimed to determine the effect of hormonal treatment with kisspeptin, GnRH and hCG on plasma testosterone concentration and semen characteristics in buck Cyprus goats during non-breeding season as compared with breeding season. This study was executed at the Ruminant Researches Station pertaining to the Directorate of Agricultural Researches, Ministry of Agriculture, Abu-Ghraib, Baghdad (latitude 33˚20' N) for the period from November 15th, 2012 to December 31^st 2013. A total of 20 buck Cyprus goats 2 years old and averages 55 kg body weight. During non-breeding season bucks were randomly divided into five equal groups (4 bucks / group). The first group (A1) was regarded as a control group, i.m injected with normal saline, whereas, the second (A2) and third (A3) groups were i.v injected with 4 and 8 µg / kg body weight of Kisspeptin-10 respectively. The fourth (A4) and fifth (A5) groups were i.m injected with hCG (250 IU / buck) and GnRH (20 µg / buck) respectively. Plasma testosterone concentrations were significantly (P≤ 0.01 and P≤ 0.05) increased at 20, 30, 40 and 50 min post-treatment in A5, A2 and A3 groups as compared with control A1. Mass motility and individual motility were significantly (P≤ 0.01) in A5, A4, A2 and A3 as compared with control during non-breeding season. In conclusion, our results show that Kisspeptin-10, GnRH and hCG can stimulate the quiescent hypothalamic–pituitary–gonadal axis of bucks during non-breeding season by increasing plasma testosterone concentration post treatment that leads improving some semen characteristics during non-breeding season.
Key words: kisspeptin-10 , GnRH , hCG, bucks, testosterone, semen characteristics
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