COMPARISON BETWEEN TWO FEEDING RATES AND THREE FEEDING FREQUENCIES FOR HYBRID SURUBIMS REARED IN CAGES

ABSTRACT This study evaluated the effects of feeding frequency and feeding rate on productive performance of hybrid surubims reared in cages with automatic feeding. Three feeding frequencies (6, 12 and 24 meals day-1), and two feeding rates (4% and 8% of body weight per day, BW day-1) were evaluated. Hybrid surubims (Pseudoplatystoma corruscans × Pseudoplatystoma fasciatum) with average weights of 24.20 ± 0.80 g were distributed in 18 cages of 1.0 m³ at a density of 60 fish m-3. Fish were fed commercial ration containing 40% crude protein, and feeding took place at night using automatic feeders. The study lasted 47 days. With a feeding rate of 4% BW day-1, the final weight (FW) of the surubims was higher when feed was supplied as 24 meals day-1 (66.92 g). However, using 8% BW day-1, the FW was greater with a feeding frequency of 12 meals day-1 (106.90 g). Regardless of feed frequency, the values of daily weight gain and standard length of surubims were higher with the feeding rate of 8% BW day-1. Therefore, the feeding rate of 8% BW day-1, provided in 12 meals day-1, provided better productive performance for hybrid surubims (Pseudoplatystoma corruscans × Pseudoplatystoma fasciatum) reared in cages.摘要 本研究探讨了投喂频率与投喂率对自动投喂网箱养殖杂交苏氏鲶（学名：*Pseudoplatystoma corruscans* × *Pseudoplatystoma fasciatum*）生产性能的影响。试验设置3个投喂频率梯度（每日投喂6、12、24次）与2个投喂率梯度（每日投喂体重的4%、8%，即BW day⁻¹，其中BW为体重（Body Weight））。初始平均体重为24.20±0.80 g的试验鱼被分配至18个1.0 m³的网箱中，养殖密度为60尾·m⁻³。试验所用饲料为粗蛋白含量40%的商品配合饲料，投喂时段为夜间，采用自动投喂机完成饲喂，试验周期共计47天。当投喂率为4% BW day⁻¹时，每日投喂24次组的杂交苏氏鲶终末体重（Final Weight, FW）更高，达66.92 g；而当投喂率为8% BW day⁻¹时，每日投喂12次组的终末体重更高，为106.90 g。无论投喂频率如何，投喂率为8% BW day⁻¹组的日增重与标准体长均显著更优。综上，以每日12次的投喂频率搭配8% BW day⁻¹的投喂率，可使网箱养殖的杂交苏氏鲶获得更佳的生产性能。