Buffalo sperm survival in glycine-yolk extenders

Abstract

SUMMARYSurvival of buffalo sperm in glycine-yolk extenders stored at 5°C was investigated. Eight glycine-yolk extenders containing variable levels of glycine (1·7 and 3·8%), glycerol (0 and 7%), fructose (0 and 1%) and 20% egg yolk, were compared with the conventional 4% glycine–50% egg yolk (control 1) and a 0·2 mol Tris-yolk extender (control 2). The highest rate of sperm survival in glycine extenders occurred in the one containing 1·7% glycine, 7% glycerol, 1% fructose and 20% egg yolk. All glycine extenders however, including control 1, were statistically (P < 0·01) inferior to the Tris-yolk. Sperm survival at the 4th day of storage for the glycine extenders ranged between 30 and 63% but it was 83% for the Tris-yolk.Adjusting the pH of the glycine extender to 6·5 increased the percentage of sperm survival but it was still below that occurring in the Tris-yolk. Sperm survival in glycine yolk adjusted to pH values of 5·9, 6·5 and 7·1 were 55, 65 and 60% compared with 75% for the Tris-yolk control.