The Effect of Dietary Organic Selenium and Folic Acid Supplementation on Productive and Reproductive Performance of Male Rabbits under Heat Stress Conditions

The objective of this work was to study the effects of organic selenium and folic acid supplementation on productive performance and reproductive performance of rabbit bucks exposed to hot condition during summer condition. Twenty-eight male V-line rabbits 7-8 months old with average initial body weight of 3.4090.05 kg were randomly divided into four groups of 7 bucks each. Group 1 served as control fed a basal diet. Groups 2, 3 and 4 fed basal diets supplemented with 0.6 mg organic selenium /kg diets (S), 2 mg folic acid /kg of diets (F), and 0.6 mg organic selenium plus 2 mg folic acid/kg of diets (S+F) for 12 weeks, respectively. During experimental period, the average maximum temperature and relative humidity inside the rabbitry were 30.8±0.22°C, and 81.4±1.05%, respectively and the temperature-humidity index was 29.9 (severe heat stress). Feed supplemented with S, F or their combination significantly increased bucks live body weight and feed intake and significantly decreased rectal temperature compared with control group. Ejaculate volume, mass motility, sperm concentration, total sperm output, total motile sperms, live and normal sperm, total functional sperm fraction and initial fructose were significantly increased, while reaction time and semen pH significantly decreased in rabbit bucks received S, F or S+F compared to control group. Administration of S, F or S+F increased (P < 0.05) seminal plasma total proteins, globulins, alkaline phosphatase, acid phosphatase and lactate dehydrogenase. Conversely, seminal plasma aspartate aminotransferase, alanine aminotransferase were significantly decreased compared to the control group. Seminal plasma lipid peroxidation as indicated by thiobarbituric acid-reactive substances was significantly decreased while, seminal plasma antioxidant enzymes were significantly increased due to S, F or S+F supplementation. Significant increase was determined in blood plasma testosterone level. In conclusion, feeding organic selenium and folic acid improved semen quality, antioxidant status and reproductive traits of rabbit bucks during heat stress. Thus, the organic S and folic acid seem to be essential for productive and reproductive efficiency of rabbit bucks under severe heat stress during summer season.