INFLUENCES OF SEASON AND DIETARY SUPPLEMENTATION WITH SELENIUM AND VITAMIN E OR ZINC ON SOME BLOOD CONSTITUENTS AND SEMEN QUALITY OF NEW ZEALAND WHITE RABBIT MALES.

Abstract

In a first experiment, six New Zealand White (NZW) rabbit males (12-15 months old) were subjected to winter (16 ± 3ºC and 71 ± 8 % RH) and then to summer (35 ± 3ºC and 46 ± 8 % RH) conditions to study the influence of hot summer season on sorne blood constituents and semen quality of rabbits males. The results showed that hot summer season significantly increased glucose, cholesterol, phospholipid, total lipid concentrations and transaminase enzymes activity in blood, whereas a significant decrease in blood concentrations of total protein, albumin and testosterone were recorded. During hot summer, there were significant rises in whole semen transaminase levels and dead sperm %, cholesterol and total lipids of seminal plasma, while total sperm and live sperm concentrations and sperm motility % were significantly decreased. In addition, hot summer season caused a decline in the mean values of both concentration rate % (P<0.01) and litter size at birth (P<0.05), as compared with those of winter season.In a second experiment, performed during the hot season, 3x6 NZW males received a basal diet supplemented or not with 0.7 mg Se+ 40 mg Vit. E/kg DM or 35 mg Zn/kg DM. A significant rise in blood testosterone, total sperm concentration and whole semen transaminase activity was recorded with Se + Vit. E supplementation, while a supplementation of Zn to the basal diets caused a significant decline in both blood and seminal plasma cholesterol, total lipids concentrations and transaminase enzymes level. On the contrary, a significant rise in testosterone concentration was detected. Also, semen volume, total live sperm concentrations, sperm mobility %, conception rate % and litter size at birth were significantly increased due to Zn supplementation to the heat stressed rabbit males.