EFFECT OF AGE, AND VITAMIN E AND SELENIUM ADMINISTRATION ON SEMEN CHARACTERISTICS OF NEW ZEALAND WHITE RABBIT BUCKS

Abstract

The aim of this study was to investigate the effect of age and supplementation with vitamin E and selenium combination on semen characteristics of New Zealand White (NZW) rabbit bucks. Thirty six NZW rabbit bucks were divided into three equal experimental groups according to their age. Group 1: young age (4-5 months), Group 2: middle age (9-10 months) and Group 3: old age (20-24 months). Each group was divided into two subgroups (treatment and control).Treated group was subcutaneously injected with 50 mg vitamin E and 0.1 mg selenium per kg live body weight, while the other was given saline solution and served as control. Experimental animals were injected once a week for 12 weeks. After six weeks of treatments, semen was collected weekly for six successive weeks. Reaction time was recorded; semen characteristics and plasma testosterone were estimated. Results showed that the young age group had significantly (p < 0.05) lower sperm cell concentration/ml, total motile sperm/ml and insignificantly lower initial motility and sperm viability than those recorded in other ages. The middle age group had significantly (p < 0.05) higher whole ejaculate volume than other groups. Also, they had significantly (p < 0.05) higher sperm membrane integrity and significantly (p < 0.05) lower fructose level than those recorded in the old age group, but not significant with the young age group. Animals treated with Vit. E and selenium showed significantly (p < 0.05) improvement in most semen quality traits compared with control animals. Averages of sperm viability, motility, sperm concentration, total motile sperm per ml, ejaculate volume, sexual libido and sperm membrane integrity were significantly higher in bucks received Vit. E and selenium than those recorded in control bucks. In addition, best results were observed in the middle age group, meanwhile, semen characteristics of young and old rabbit bucks did not decrease dramatically and still in acceptable range. It could be concluded from our study that young and middle age bucks with supplementing with Vit. E and selenium could be used successfully and efficiently in rabbit breeding systems.