Dietary protein level influenced reproductive development of hoven’s carp Leptobarbus hoevenii female broodstock

The present study demonstrates the effects of varying dietary protein levels on reproductive indices, energy deposition, steroid hormones and oocyte status of hoven’s carp Leptobarbus hoevenii female broodstock. Eighty-one broodstock (1.86 ± 0.02 kg) were randomly distributed into nine tanks representing three dietary treatments; 350 g/kg (P35), 400 g/kg (P40) and 450 g/kg (P45) in triplicates. Feeding was conducted to apparent satiation for eight months. Results revealed an increased gonadosomatic index, fecundity, oocyte diameter and condition factor in fish fed P40, followed by P35 and P45, but had no effects on thehepatosomatic index, intraperitoneal fat, viscerosomatic index and oocyte weight. Dietary protein levels did not affect protein, lipid, glycogen and total energy in fish muscle. Conversely, protein and total energy were elevated in oocytes of fish fed P40 corresponded to the decrease in protein, lipid and total energy in the liver. Estradiol was detected higher in fish fed P40 and P35 compared to P45. Histological examination of oocytes revealed vitellogenic stage for fish fed P35, completion of vitellogenic stage and early maturation for fish fed P40 and hydration stage for fish fed P45. The present study suggests that 400 g/kg dietary protein provides generally better reproductive development of hoven’s carp female broodstock in captive conditions. •Dietary protein of 400 g/kg improves gonadosomatic index, fecundity, oocyte diameter and condition factor of fish.•Dietary protein of 400 g/kg improves egg maturation stage with elevated estradiol content in blood plasma.•Dietary protein of 400 g/kg encourages protein and energy mobilization from the liver to the oocytes during maturation.•Dietary protein of 450 g/kg is unnecessary as it deteriorates the reproductive development of fish.