Sperm characteristics and growth of Rhamdia quelen males fed on rations formulated with vegetable food and different digestible energy levels supplied by soy bean oil / Short Communication Características espermáticas e crescimento de machos Rhamdia quelen alimentados com rações formuladas com alimentos vegetais e diferentes níveis de energia digestível fornecidos pelo óleo de soja

Abstract

This research was carried out to evaluate the effects of rations formulated with vegetable foods and different levels of digestible energy supplied by soybean oil, on sperm characteristics and growth of Rhamdia quelen males. The fishes were fed on over 255 days with rations containing 350 g crude protein (CP) kg -1 and 2700, 2950, 3200, 3450 and 3700 kcal of digestible energy (DE) kg -1 . A randomized experimental design was used with five treatments and three replicates. A 8 m 2 tank containing six females and three males was an experimental unit. The fishes were weighted fortnightly to correct the feeding rate. All males receipted an intramuscular injection of 2.5 mg of crude pituitary extract (CPE) kg -1 to perform the sperm collection. The sperm characteristics were assessed on fresh sperm immediately after collection. All data were subjected to ANOVA and regression analysis. The growth, sperm volume, sperm concentration, or time of sperm motility were not affected (p < 0.05) by rations. In addition, ration containing 3318.75 kcal of DE kg -1 improved the integrity of sperm membrane, suggesting a theoretical higher sperm survival rate of 98.22%. In conclusion, ration formulated with vegetable foods and different levels of soy bean oil as energy source did not interfere on growth of Rhamdia quelen males. In addition, the diet energy supplied by mainly soy bean oil offered a nutritional condition that improved the sperm quality since males fed on ration with 3318.75 kcal of digestible energy kg -1 has been increased the membrane integrity of sperm cell.