ABSTRACT

Twenty-seven mature New Zealand White rabbit bucks were used for this study to evaluate the effect of an exogenous Gonadotropin Releasing Hormone (GnRH) administration on seminal characteristics and libido. The rabbits were randomly selected and assigned into three treatment groups designated as T1, T2and 13; in a completely randomized design (CRD). The exogenous hormone was administered at the rate of 0.0Oml, 0.20m1 and 0.40m1 per kilogram of body weights of the animals for T1, T2and T3 respectively. Semen samples were collected at the beginning of the experiment for baseline studies and after 48 days of administration of the hormone. The parameters of interest include semen volume, mass motility, sperm concentration, live sperm proportion, total spermatozoa per ejaculate, total viable spermatozoa, percentage normal spermatozoa, percentage abnormal spermatozoa, semen viscosity, semen color, libido score and reaction time. Results obtained from the baseline study showed no significant difference (P>0.05) in the various treatments for semen volume, mass motility, sperm concentration, live sperm proportion, number of spermatozoa per ejaculate, total viable spermatozoa, normal sperm count, semen viscosity, semen color, libido score and reaction time. However, at the end of the study, the values obtained showed that semen volume was significantly (P<0.05) higher in T2(0.69iti1) than T1 (0.55m1). In sperm concentration, 12 (126.06 x 106) and 13 (125.49 x 106) were found to be statistically similar and significantly (P<0.05) higher than the control group, T (113.18 x 106), with 12 having the highest value. In Live sperm proportion, T2 (93.65%) and 13(91.18%) were found not to differ significantly (P>0.05) from each other but were significantly (P<0.05) higher than T1 (85.83%). 12 recorded a relatively higher proportion of live spermatozoa than T and 13. It was observed that total spermatozoa per ejaculate was significantly (P<0.05) higher in 12 (87.34 x 106) than T1 (62.71 x 106). For total viable spermatozoa, 12 (684.02 x i0) was observed to be significantly higher than T (508.63 x iO) and 13 (628.17 x iO). In Semen viscosity, 12(3.00) was observed to be significantly higher (P<0.05) than T (2.33) and 13(2.67). The lowest score was recorded in Ii. In Libido Score, T2 (4.33) was observed to be significantly higher than T1 (3.67), but was significantly similar to T3(4.00). There was no significant difference (IP>0.05) observed in other values in mass motility, percentage normal spermatozoa, percentage abnormal sperm, semen color and reaction time. It is concluded from this study that the exogenous GnRH used for this experiment led to a more enhanced reproductive performance with respect to libido and semen quality and had no harmful effect on the rabbit, therefore recommended for use to rabbit breeders and producers at the rate of O.20m1/kg.