Gelatin protects semen stored for 72 hours at 5ºC

Cooled ram sperm stored for prolonged intervals is not suitable for artificial insemination due to sperm damage. However, the addition of gelatin to rabbit and pig semen protected sperm viability during prolonged storage. The objective was to evaluate effects on sperm quality by adding gelatin to the extender for storage of ram sperm at 5 °C. Eight rams were used 5 ejaculates per ram. Each ejaculate was divided and added to two extenders: E1 (whole milk 10%, 0.2 g d-glucose, 50 mg streptomycin and 100 mL of mili Q water); and E2 (E1 plus 1.5% gelatin). Sperm was stored at 5 °C and evaluated at 0, 24, 48 and 72 h. During the first 48 h of storage, sperm motility and acrosome integrity were not significantly different between extenders, although at 72 h, sperm in E2 had better motility than sperm in E1 (51.9 ± 6.3 vs 31.1 ± 2.8%, respectively, P < 0.05) and better acrosome integrity (66.3 ± 17.5% vs 42.9 ± 23.2%, respectively, P < 0.05). However, membrane integrity, morphology and integrity of DNA and membrane were not significantly different between extenders at any time. Addition of gelatin to the cooling extender promoted maintenance of sperm motility and acrosome integrity and has potential for long-term storage of sperm prior to cervical artificial insemination.