Diluents for Bovine Semen. X. Livability of Spermatozoa Stored at Ambient Room Temperatures in Diluents Containing Skimmilk

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Abstract
Four spermatozoan livability experiments were conducted at ambient room temperatures to determine (a) the feasibility of substituting skimmilk for coconut milk in the West Virginia University coconut milk extender (CME); (b) the optimal levels of glucose, skimmilk, and sodium citrate; (c) the optimal initial pH; and (d) the relative merit of lactic and citric acids for pH adjustment. Motility was maintained equal to or slightly higher in glucose-containing (0.5 to 2.0%) ambient temperature skimmilk (ATS) diluents with 5 to 15% skimmilk and 1.9 to 2.25% sodium citrate than in CME. Adjustment of initial pH with citric acid resulted in higher livability than adjustment with lactic acid. Livability increased with both acids as initial pH was increased from 6.4 to 7.2. The optimal ATS diluent contained 1.0% glucose, 1.9% sodium citrate, 2.5 to 10% skimmilk, and sufficient citric acid to adjust initial pH to 7.2 (4 to 8 mg./100 ml of diluent). The diluent also contained 0.5% egg yolk, catalase, antibiotics, and sulfanilamide. In general, sperm agglutination increased as sodium citrate concentration decreased and as initial pH increased. Incorporation of glucose markedly reduced agglutination. At pH 7.2, even with 1.0%, glucose, most ejaculates (9/10) showed considerable agglutination with 1.6% sodium citrate; it was much less extensive with 1.9% sodium citrate and occurred in only 2 of 10 ejaculates. Ejaculates from different bulls showed wide variability in livability in both CME and ATS diluents.