LAUSR

Glycerol is a least toxic and most effective cryoprotectant for cryopreservation of poultry semen, but due to its contraceptive properties removal of glycerol is usually needed prior to artificial insemination. Dimethylsulfoxide (DMSO), a small amphiphilic molecule used as penetrating cryoprotectant for biological cells, has been recognized as an adequate alternative for cryopreservation of sperm from several species. This study was designed to evaluate the efficacy of different concentrations of DMSO as cryoprotectant for Indian red jungle fowl (Gallus gallus murghi) sperm. Semen was collected from Indian red jungle fowl cocks, pooled and divided into five aliquots. Different concentrations of DMSO (0%, 4%, 6%, 8% and 10%) were compared. Diluted semen was cooled from 37 °C to 4 °C (-0.275 °C min-1), 20% glycerol added to control and equilibrated for 10 min. After equilibration, semen was filled in 0.5 mL French straws, kept over liquid nitrogen vapors for 10 min and plunged into liquid nitrogen. Semen samples were thawed at 37 °C for 30 s. Cryo-survival of Indian red jungle fowl sperm was affected by cryopreservation stages and different concentrations of cryoprotectant used. Highest sperm motility (85.0 ± 2.9; 80.0 ± 3.5; 71.3 ± 4.3; 60.0 ± 1.3), plasma membrane integrity (79.5 ± 3.8; 75.3 ± 2.4; 72.8 ± 3.3; 60.3 ± 2.8), viability (80.8 ± 4.6; 75.5 ± 2.9; 71.0 ± 7.6; 58.8 ± 1.3) and acrosomal integrity (76.3 ± 2.4; 72.0 ± 6.0; 62.5 ± 4.3; 55.0 ± 3.2) were recorded in a diluent having 8% DMSO at post-dilution, cooling, equilibration and freeze-thawing. Highest fertility results were obtained after artificial insemination with 8% DMSO compared to 20% glycerol (73.0 ± 4.4 vs 53.1 ± 4.3, P < 0.05). It is concluded that 8% DMSO as a permeable cryoprotectant improves the post thaw semen quality and fertility in Indian red jungle fowl and can be used effectively to avoid the contraceptive effects of glycerol.