投饲率对草鱼生长、体组成和能量收支的影响

为了建立草鱼(Ctenopharyngodon idella)的精准投喂模型管理系统,研究了不同投喂水平下草鱼的能量收支。实验在水温(27.5±2.0)℃条件下,选用初始体重(71.03±1.13)g的草鱼,共设5个不同投饲水平(饥饿、1%鱼体重(1%BW)、2%BW、4%BW和饱食),研究摄食水平对草鱼生长、鱼体组分和能量收支的影响。结果显示:随投喂水平的增加,草鱼鱼体水分减少,粗蛋白含量、粗脂肪含量和能量增加,灰分含量先减少后增加。特定生长率和热积温生长系数均随投喂水平的增加先增加再降低,在5%鱼体重时达到最大,且高于饱食投喂组。饵料转化率(FE)在投喂水平为体重2%组最高,且显著高于其他各组。干物质和能量表观消化率随投喂水平的增加而显著增加,蛋白质表观消化率在投喂水平为体重2%组显著高于其他组。生长能比例随投喂水平的增加而显著增加,而在体重2%组到饱食组间均无显著性差异;代谢能与生长能相反。在最大投喂水平下的能量收支方程为:100 C=21.72 F+4.25 U+45.85R+28.18 G或100 A=61.94R+38.06G。结果表明,5%鱼体重的投喂量为草鱼此阶段的最佳投喂水平。

Effects of ration levels on growth,body composition and energy budgets of grass carp,Ctenopharyngodon idella

A growth trial was carried out at 5 ration levels ( starvation, 1% BW, 2% BW, 4% BW and satiety) to in-vestigate the effects of ration levels on the growth, body composition and energy budget of grass carp Ctenopharyngodon idella (initial body weight 71. 03 ± 1. 13 g) at (27. 5 ± 2. 0)℃. The weight gain rate and the thermal-unit growth coeffi-cient both increased to maximum at 5% BW and then decreased. Feed conversion efficiency was highest in the ration level of 2% BW. Moisture contents decreased while crude protein, lipid and gross energy increased. Ash content initially de-creased and then increased with ration levels. Apparent digestibility of dry matter and energy increased with the increasing ration levels. Apparent digestibility of protein was significantly higher than other groups at the ration level of 2% BW. The growth energy reached to a plateau from ration level of 2% BW to satiety, and metabolic energy changed in the opposite way. At satiety, the energy budget equation was: 100 C=21. 72 F+4. 25 U+45. 85R+28. 18 G or 100 A=61. 94R+38. 06G. Based on the above results we conclude that 5% BW was the best ration level for grass carp at this stage.