263. Substitution of skim milk with bovine serum albumin in a stallion semen diluent
Z. Gibb A , C. G. Grupen A , L. H. A. Morris B , G. Evans A and W. M. C. Maxwell AA Faculty of Veterinary Science, The University of Sydney, The University of Sydney, NSW, Australia.
B EquiBreed NZ Ltd, Cambridge, New Zealand.
Reproduction, Fertility and Development 20(9) 63-63 https://doi.org/10.1071/SRB08Abs263
Published: 28 August 2008
Abstract
Skim milk has long been utilised as a source of protective proteins in stallion semen diluents. However, skim milk is also thought to contain components that are toxic to sperm and reduces the clarity of sperm suspensions, which impedes sperm assessments. This may also reduce the effectiveness of staining procedures used to process sperm for flow cytometric sex-sorting. The aim of this study was to ascertain the optimal concentration of bovine serum albumin (BSA) to replace skim milk in a traditional stallion semen diluent, Kenney's Modified Tyrode's (KMT) Medium1, for handling and processing stallion sperm before flow cytometric sex-sorting. Two ejaculates were collected from each of three pony stallions. Each ejaculate was divided into five aliquots and diluted in either KMT with skim milk or KMT supplemented with 0, 0.25, 0.5 or 1% BSA. Diluted samples were further divided into two aliquots and either stored at 15°C for 18 h before incubation and assessment, or incubated and assessed immediately upon arrival. Samples were incubated at 34°C and evaluated at 0, 45 and 90 min for objective motility and acrosome integrity. No interactions were observed between any treatments over time. There was a lower percentage of intact and a higher percentage of detached acrosomes for sperm incubated in KMT containing 0% BSA than all other treatments. A greater proportion of sperm incubated in KMT with skim milk had partial acrosome damage compared with other treatments. There was no difference in % total motility for sperm incubated in KMT with skim milk, and KMT containing 0.5 and 1% BSA (Table 1). These results indicate that BSA may be suitable as an alternative protein source in stallion semen diluents. Further studies are required to compare sex-sorting rates and sperm quality after sex-sorting, incubation and staining in skim milk compared with BSA-based media.
(1) Padilla, A W and Foote, R H 1991, ‘Extender and centrifugation effects on the motility patterns of slow-cooled stallion spermatozoa’, Journal of Animal Science, vol. 69, no. 8, pp. 3308–331
