Clinical, Endocrinological and Spermatological Studies after Endotoxin Injection in the Boar

Abstract

Three adult boars were injected intravenously with endotoxin from Salmonella typhimurium. Blood plasma was analysed for the contents of 15-ketodihydro-PGF2 alpha, LH and testosterone. Total amount of white blood cells and differential counts were determined in whole blood. Semen was examined for concentration, motility, volume and morphological appearance of the spermatozoa. The boars were slaughtered three months after the endotoxin injection and the testes were examined. The total number of white blood cells decreased and the levels of 15-ketodihydro-PGF2 alpha rose immediately after the endotoxin administration. An initial increase in LH was seen in two out of the three boars. The increase in LH was followed by a testosterone increase in one boar and a testosterone decrease in the other. The third boar showed no initial increase in LH but an increase in testosterone. Semen examination demonstrated various morphological changes of the spermatozoa in all boars. The changes started to appear at about the same time after the endotoxin injection, but differed among the individuals. The examination of the testes depicted no changes from what is seen in normal animals. The present results indicate that the boar responds to endotoxin similar to what is seen in the ram. The endocrine changes, e.g. in LH and testosterone, are similar to those seen after termination of heat stress. The seminal changes indicate a disturbance located in the epididymis as well as a short-term, mild degeneration in the seminiferous epithelium.