Comparison of diluents for holding cock semen six hours at 41 C.

Beltsville Poultry Semen Extender (BPSE) and Lake's Diluent A (LDA) were compared with minimum essential medium (MEM) for their ability to maintain the fertilizing capacity of cock semen held 6 hr at 41 C. Motility significantly declined from the beginning to the end of the holding period for semen in BPSE and LDA. Only in LDA, however, were the number of live spermatozoa significantly reduced. Although there were no differences in oxygen (O2) consumption measured at 1 and 6 hr for semen in BPSE and MEM, a significant reduction in O2 consumption was observed between these time periods for semen in LDA. Fertility of semen held in MEM (90.3%) was significantly higher than the unstored control semen (82.9%) and semen held in either BPSE (3.5%) or LDA (1.9%). No differences in hatchability of fertile eggs were observed between the semen groups.