ATP content and sperm motility of extended bovine semen under different storage conditions.

The effects of incubation temperature (+20 degrees C vs +35 degrees C) and media type on the ATP content and motility of spermatozoa were determined in fresh bovine semen in order to develop a method for assaying post-thaw quality. Semen was obtained from 3 bulls at 2 occasions. The spermatozoa were washed using a Ficoll-containing medium before being resuspended in each of 4 different media (I. 0.9% NaCl; II. Tris-buffer solution; III. seminal plasma; IV. seminal plasma+Tris-buffer solution) and incubated for 6 h. The least-squares means for ATP content were higher (p less than or equal to 0.05) at +20 degrees C than +35 degrees C for all media except no. I. By contrast, the least-squares means for sperm motility were higher (p less than or equal to 0.05) at +35 degrees C than at +20 degrees C in media II and III. A decrease over time in ATP content and motility at both temperatures was also observed. The single most important factor responsible for changes in ATP content and sperm motility was the temperature and the medium, respectively.