The practical use of density of whole bull semen to determine the volume of an ejaculate at AI laboratories

Determining the volume of an ejaculate is an important part of processing semen in bovine AI laboratory practice. A multi-AI laboratory study was performed to estimate the density of whole bull semen, and whether the use of this value as a standard is suitable for practical use when semen of different breeds is processed at different AI laboratories. The density of whole bull semen had been determined for 90 ejaculates at five AI laboratories (five breeds). The results showed no effect of bull (p = 0.766), breed (p = 0.279) and laboratory (p = 0.183). All duplicate measurements within the same sample were within the level of agreement (5%). Using the mean value of 1.053 g/ml as a golden standard for the density of whole bull semen is therefore suitable for use in routine bovine AI laboratory practice.