Ảnh hưởng của phương thức cho ăn lên chất lượng nước, sinh trưởng và tỉ lệ sống của cá trê vàng (<i>Clarias macrocephalus</i>) nuôi trong hệ thống tuần hoàn

Abstract

     Effect of feeding techniques on water quality, growth and survival of bighead catfish (Clarias macrocephalus) reared in a recirculating system were studying for 90 days. This study aimed to optimize the efficient use of feed, manage the water quality for improving fish growth and survival rate. The experiment stocked fish (initial body weight of 9.99 g ± 1.36) into four treatments: continuous feeding and feeding frequency of 2, 3, 4 times per day. Fish were fed at adlibitum using 41% protein pellet. During the experiment, pH of all treatments ranged from 6.8 to 8.7 and tended to decrease with the increase of feed intake and culture duration. TAN and NO₂^- fluctuated throughout the experiment. NO₂^- ranged from 0.000 to 0.869 mg / L. Generally, water quality parameters were in suitable ranges for fish growth. Feeding frequency of twice a day resulted in the optimal results with stable water quality, growth rate of 2.43 ± 0.49% / day, survival rate of 70%, productivity of 66.75 ± 11.89 kg/m³, feed conversion rate of 1.20 ± 0.10 and water use of 0.22 ± 0.04 m³/kg of fish.

Keywords: Clarias macrocephalus, recirculating system, feeding frequency