食物与水环境因子对草鱼(Ctenopharyngodon idellus C.et V)脆化过程的影响

Effects of diets dose and water quality on the transformation of common grass carp(Ctenopharyngodon idellus C.et V) to crisped grass carp

结合生产实际,探讨了普通鲩鱼向脆肉鲩转变的过程和实质,提出用“断裂应力δρ”作为脆肉鲩脆化程度的划分标准,并实验研究了不同水温、水流速度、水化学因子和蚕豆饲料投喂量等因素对脆肉鲩生长和品质的影响.结果表明,以脆肉鲩不同部位组织热变性蛋白质的断裂应力δρ为指标的脆化程度主要由蚕豆饲料摄食量所决定,脆肉鲩养殖的良好条件为：放养规格1.50～2.00kg/尾,放养密度150～170尾/666.7 m^2,,水温在18℃以上;摄食量达到3.962～5.263 kg/kgbw时,可实现饲料系数约为6,脆化程度指标δρ为0.422～0.611 kg/cm^2的合格商品脆肉鲩.水体水化学因子等环境条件只对草鱼脆化起间接辅助作用,它们通过改变草鱼的摄食量和营养（能量）转化率,影响机体正常的生理活动而导致草鱼肌肉蛋白合成与积累不同等表达出来,良好的水环境质量利于脆肉鲩养殖.普通鲩鱼脆化养殖的最佳养殖条件为适当的饲料投喂剂量（4.3kg/kgbw）,适宜的水环境因子条件（水温（30±2）℃、DO≥5mg/L、pH在5.8～6.2之间）.为进一步完善脆肉鲩养殖生产操作流程,提高脆肉鲩养殖技术,合理调控投饲量和养殖水环境因子,从而提高脆肉鲩品质和养殖效益进行了讨论.

It has been demonstrated that Common Grass Carp can be changed into better taste Crisped Grass Carp by being fed with broad bean Vicia faba. We conducted a two-year study to investigate the effects of feeding level and water quality on the crisping. Results show that the degree of crisp was mainly determined by and positively correlated with the feeding level of Vicia faba, with the optimal feeding rate of about 4.3kg/kg bw for producing high quality Crisped Grass Carp. The water quality also has some effects on crisping of Grass Carp by influencing the fish＇s physiology and metabolization. The optimal water quality parameters were temperature at （30 ± 2）℃, DO≥5mg/L, and pH at 5.8～6.2. The feeding of Vicia faba and suitable water quality parameters lead to increased protein synthesis capacity and enhance the production of quality crisp Grass Carp.