Effect of the ambient temperature on the viability of the semen of boars

Abstract

The pigs shown to be sensitive to conditions of heat and, as a result, may have changed their reproductive efficiency during periods of high temperature. The aim of this study was to evaluate the effect of environmental temperature on seminal viability of boars. After harvest, we assessed total motility (%), progressive motility (%), vigor (0-5), membrane integrity (%) and percentage of abnormal sperm from semen samples. The animals were subjected to two treatments: Treatment I - animals kept in cages under temperature conditions within the standards of thermal comfort; Treatment II - animals kept in cages under temperature conditions outside the standards of thermal comfort. Semen samples were placed between slide and coverslip heated to 37 °C for analysis of MT (%) MP (%) and vigor (0-5). Evaluations of membrane integrity slides were stained with the dye eosin-nigrosina. In assessing the pathology slides were stained with dyes bengal rose and gensiana violet. In all cases, the slides were observed under optical microscope at a magnification of 40 x. The results showed a significant effect of temperature on seminal viability of animals subjected to different thermal conditions, which revealed that high temperatures can result in reduced semen quality.