Esterified glucomannan improves aflatoxin-induced damage of sperm parameters during liquid storage of ram semen at 5 °C

Abstract

The aim of the present work was to study the effects of aflatoxin (AF) on sperm parameters in rams, and to determine the protective efficiency of esterified glucomannan (EG) co-administered with AF up to 96h of the liquid storage of ram semen at 5°C. Thirty-two Merino rams (12–14months old) were used. The animals were examined for their general health status. To ensure their adaptation to the environment and the new feeding regimen, a 15-day acclimatization programme was applied to the animals, prior to the start of the study. Experimental feeding was continued for ninety-two days. The experimental design consisted of four dietary treatments. The control group (C) was fed with commercial feed. The AF group was fed with commercial feed plus 250μg/day of total AF. The EG group received commercial feed plus 2g/day of EG. The AF + EG group was given commercial feed plus 250μg/day of total AF and 2g/day of EG. In the study, ejaculates were obtained from rams twice a week for 12weeks, using an electro-ejaculator. After collected, the ejaculates were diluted with a skimmed milk extender, and stored at 5°C. Sperm motility and rates of abnormal and nonviable spermatozoa were determined for the different treatment groups at 5°C at 0, 24, 48, 72 and 96h of liquid storage.During the first two weeks of the trial, the groups did not statistically differ from each other for sperm motility or rates of abnormal and nonviable spermatozoa at 0, 24, 48 and 96h of storage. As from the third week, the short-term storage of semen produced statistically significant differences between the AF group and the other treatment groups for sperm parameters (p<0.05). The administration of aflatoxin was observed to have reduced sperm motility and to have increased the rates of abnormal and nonviable spermatozoa in comparison to the control group (p<0.05), while EG co-administered with AF was determined to have ameliorated the adverse effects of AF on sperm parameters, and this ameliorative effect continued throughout the short-term storage of semen. On the other hand, aflatoxin administration resulted in the deterioration of the sperm parameters in the following weeks, and the combined administration of EG + AF reversed this adverse effect, thus, bringing the sperm parameters closer to the values of the control group. This study demonstrated that, in rams, AF adversely affected sperm, biochemical and testis parameters, and that the combined administration of EG and AF reversibly improved these adverse effects.