ABSTRACT
This study was conducted to determine chromatin integrity and DNA damage by DNA electrophoresis and comet assays of buffalo fresh and frozen semen. Semen samples were collected from four buffalo bulls and evaluated after freezing for semen motility, viability, sperm abnormalities, chromatin integrity and DNA damage. A significant variation was found in semen parameters after thawing. Highly significant differences [P<0.001] in chromatin integrity were observed between fresh and frozen semen. For the fresh semen, there was no significant difference between the bulls for chromatin integrity; however, a significant variation [P<0.05] was detected in their frozen semen. No DNA fragmentation was observed by agarose gel electrophoresis. The percentage of sperm with damaged DNA detected by comet assay differed significantly between fresh and frozen semen. A significant negative correlation was recorded between motility and DNA damage [r=-0.68, P<0.05]. Sperm abnormalities and DNA fragmentation were significantly positively correlated [r=0.59, P<0.05]. In conclusion, DNA damage evaluation can provide reassurance about genomic normalcy and guide the development of improved methods of selecting spermatozoa with intact DNA to be used in artificial insemination
ABSTRACT
In this study, a total number of 307 female New Zeal and white rabbits were used to study the relationship between the color of the vulva and the reproductive performance. By the use of A. I. technique, the conception rate [CR], pregnancy duration [PD] and litter size [LS] were recorded. Four groups were classified according to the vulva color as congested red, pink, purple and pale. Highly significant variations were recorded between the four groups in all parameters studied. The highest CR, shortest PD and largest LS were recorded for the congested red vulva group. The pale vulva group failed to conceive