EFFECT OF SOME EXTENDERS ON CHILLED RABBIT SEMEN STORED AT 5°C FOR 48 HOURS

Abstract

With the global demand for rabbit meat steadily increasing, commercial rabbit breeding has become more dependent on artificial insemination (AI) rather than traditional natural mating. The study aimed to compare coconut milk (CME) as a novel extender for rabbit semen with Tris Yolk-Glucose (TYG) and Lactose Yolk-Citrate (LYC), to evaluate the in vitro presrevability of rabbit spermatozoa stored at 5°C for 48 hr. Twelve New Zealand White (NZW) rabbit bucks were used to collect semen. Semen was pooled, partioned to three portions and then diluted with one of three different extenders; Tris Yolk-Glucose, Lactose Yolk-Citrate or Coconut Milk. The dilution rate was 1:4 (volume: volume) and stored at 5°C for 48 hr., the experiment lasted for 8 weeks. Sperm motility, dead sperms, abnormal sperms and acrosome loss percentage were evaluated in chilled semen at 0, 24 and 48hr. of storage. The results showed that sperm motility was the highest at both 24 and 48hr. storage with TYG compared with LYC and CME without significant statistical differences between them. There were significant differences between extenders at 24hr. of storage with respect to the percentage of dead spermatozoa; the lowest percentages were recorded in semen stored with TYG. The CME extender gave significantly the highest values of abnormal sperms (29.16%) at 48hr. than TYG and LYC (23.16 and 26.33%, respectively). At 48hr. of storage, higher acrosome lossvalues were found with CME (27%) compared with TYG and LYC extenders (21.16 and 21.50%), respectively. The lowest values for the acrosome loss(21.16%), during the 48 hr., storage were obtained with TYG.