Artificial insemination with frozen semen in rabbits in Brazil: first litter reported

Abstract

Brazilian rabbit breeding plays an important social role through family farming. However, one of the challenges faced is the need for new genetic material from genetically improved rabbits. The artificial insemination (AI) technique in Brazil is restricted to the use of fresh or chilled semen. Hence, this is the first report of the use of frozen semen and live kits in Brazil and probably in Latin America. The aims were to evaluate the commercial viability of frozen rabbit semen in Brazil, ranging from cryopreservation to insemination. Three bucks and three rabbit does of Flemish giant rabbits were used. Semen was collected, evaluated and diluted for freezing with CUNIFreeze. Semen was frozen in a 0.5 mL straw, thawed and then filled in a blue curve rabbit AI sheath with the doe in dorsal position with ovulation induced at the same time with buserelin acetate. The ejaculate volume was 0.8 ± 0.8 mL; the mass motility was 3.3 ± 0.6; and the total motility and vigor after dilution were 65% ± 5 points and 3.7 ± 0.6, respectively. Post-thawed, the motility and vigor were 20% ± 10 and 3,0 ± 0,0, respectively. The pregnancy rate was 66.6% with a litter sizes of 5 and 2 kits. Even with a lower result of litter size compared with refrigerated semen, this report brings a new scenario for rabbit breeding in Brazil, showing that frozen semen is a feasible technique for biobanking and mainly bringing the possibility of imported semen from genetically improved bucks solving inbreeding problems.