SPERM DNA DAMAGE AND EMBRYONIC DEVELOPMENT AS RELATED TO FERTILITY POTENTIAL OF BUFFALO BULLS

Document Type : Original Article

Authors

Animal Production Res. Inst., Agric. Res. Center, Dokki, Giza, Egypt

Abstract

Conventional semen analysis are not sufficient to evaluate bull’s fertility, however it might be used as a preliminary evaluation for predicting fertility potential. Sperm DNA integrity may give a better evaluation of bull fertility potential. In the current study, six mature buffalo bulls were divided into two groups (based on a threshold of 70% motility; as high or low potential fertility). The first objective of the current study was to evaluate DNA fragmentation (measured as Comet value) in the two groups of bulls (three bulls/group) in relation to its potential fertility. The results showed that low potential fertility bulls had significantly (P<0.05) more sperm DNA damage, higher (P<0.05) sperm abnormal morphology and lower (P<0.05) sperm viability than that of sperm from the high potential fertility bulls.
Our second objective was to assess whether a relationship exists between bull’s sperm DNA damage and bull in vitro fertility. A significant variations (P<0.05) in the developmental competence of the embryos to the morula and blastocyst stages were observed. The results also showed a clear negative correlation between bull’s potential fertility and DNA integrity at and the ability of the fertilized ova to sustain its development to the morula (r=-0.756) and blastocyst stage (r=-0.643). These results indicate that measuring DNA integrity could be a powerful marker of bull’s fertility. Therefore, screening bulls for DNA damage should be emphasized along with routine semen analysis in selecting bulls either for natural mating or artificial insemination. 

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