ABSTRACT

A total of 18 rabbit bucks (9 NZW, and 9 Chinchilla), with a mean average weight of 2.13±0.07 (NZW) and 2.27±0.09 (Chinchilla), within the age of 8-9 months were used for the study to evaluate the semen quality and characterization of spenn morphology in two breeds of rabbit bucks. The study was carried out at the rabbitry Unit/Teaching and Research farm. Michael Okpara University of Agriculture, Umudike, Abia State. The semen parameters evaluated include: semen volume, colour, pH, motility, morphology, concentration, proportion of live spennatozoa, total number of spermatozoa per ejaculate. The result showed that semen volume, pH, individual motility, and percent normal spennatozoa proportion and total number of spermatozoa were not affected by breed as there was no significant (p>0.05) difference between the two breeds, while the sperm mass motility, percent live spermatozoa proportion, and spenn concentration were affected by breed, as there was significant (p<0.05) difference in the two breeds studied, in which the Chinchilla breed showed a significantly (p<0.05) higher value than the NZW. The abnonnal spennatozoa was however, significantly lower (p< 0.05) in Chinchilla (9.37 ± 0.48%) than NZW (10.20 ± 0.53%). The sperm morphological types observed were normal and abnormal. The different abnormal spermatozoa types observed in these study were abnormal head, abnormal tail, cytoplasmic droplets, abnormal mid piece, and broken cells. There were significant differences between the breeds in abnormal head, abnormal tails, neck, mid piece abnormality and broken cells. Apart from the neck mid piece abnormality, where the Chinchilla breed had a higher value, the NZW had higher values in the other abnormality types. However, the values of the semen parameters obtained in the two breeds were within the normal standard for rabbit buck, though, Chinchilla bucks proved superior in terms of semen characteristics. It can be concluded that Chinchilla showed a better reproductive potential and is hereby recommended for optimum and efficient rabbit production and breeding based on its better semen quality compared to New Zealand White