WORLD RABBIT

ABSTRACT: Today a great deal of research is focused on the development of new extenders that allow the refrigeration and maintenance of rabbit semen for a longer period of time. In this study, semen diluted with 3 different extenders (A, B, and C) and stored at two different temperatures (4°C and 38°C) were evaluated using both laboratory and in vivo tests. The best results were obtained with extender C (INRA 96) which, in the first 10 h of the test at 4°C, displayed about 80 % higher motility compared to the other two extenders and preserved optimal seminal fluid motility for over 34 h after dilution. In the test at 38 °C, the motility of semen diluted with extender C was 52 % in the fifth h vs 21 % of the semens diluted with extenders A (Lepus) and B (Verdunnungsmischung). Another test involved artificial insemination (AI) of 1800 lactating does using refrigerated semen diluited with the extenders under study. The fertility rate and litter size obtained with semen diluted with extender C was higher (78.1% and 8.65, respectively) than those obtained with extenders A (71.2 % and 8.15, respectively) and B (71.05 % and 8.13, respectively) in both parallel and sequential tests. In conclusion, extender C offers greater vitality and motility to rabbit spermatozoa, thus higher fertility rates to rabbits does. Key words: artificial insemination, rabbits, semen extenders. 6