Influence of ejaculation time on sperm quality parameters in high performance boars

Abstract

The aim of this study was to evaluate the influence of ejaculation time on sperm quality parameters in high performance boars. 447 fresh semen samples were used from 9 boars. The samples were collected by the gloved hand method and the duration of ejaculation in seconds was determined. The ejaculates obtained were divided into three groups based on the ejaculation time and into two categories based on the age of the animals. The sperm volume (using graduated bottles), total number of sperm using a Neubauer chamber, motility and intensity of motion using phase contrast microscopy and spermatic morphology using wet preparation with formaldehyde-sodium citrate solution were all evaluated. All variables were compared regarding the ejaculation time and animal age, and the correlation between these variables and the ejaculation time was also evaluated. Animals with higher ejaculation times were found to have a higher semen volume (P<0.05). A positive correlation (0.56; P<0.001) was observed between ejaculation time and the seminal volume, but correlations were low (P>0.05) with regards to other variables. Animals younger than 15 months old had lower semen volumes and higher sperm counts, as well as altered spermatic morphology (P<0.05) compared with older animals. The ejaculation time was found to be associated with the seminal volume, with little effect on the other variables. In conclusion, an adequate seminal analysis should always be performed to evaluate the fresh boar ejaculate, especially in possible semen donor animals.