饲料中蛋白质水平对克氏原螯虾生长性能及肌肉品质的影响

以初始平均体质量为(3.69±0.05)g的克氏原螯虾幼虾为研究对象,配制蛋白质水平分别为27.72%、30.09%、33.05%、35.31%和37.57%的5种等能、等脂的配合饲料,进行为期47 d的饲养试验,探索饲料中不同蛋白质水平对克氏原螯虾生长性能、肌肉质构特性、常规营养成分及氨基酸组成和含量的影响。结果表明:随着饲料蛋白质水平的增加,克氏原螯虾的增重率和特定生长率呈先上升后降低的趋势,其中饲料蛋白质水平为30.09%组虾的增重率、特定生长率显著高于其他各组(P<0.05);各组间饲料系数、虾体质量/体长比、肝体指数、得肉率以及成活率无差异统计学意义(P>0.05)。饲料蛋白质水平为27.72%组虾的肌肉硬度、咀嚼性显著高于饲料蛋白质水平为35.31%、37.57%组(P<0.05),饲料蛋白质水平为30.09%、33.05%组虾的肌肉弹性显著高于饲料蛋白质水平最低组(P<0.05),饲料蛋白质水平最高组虾的回复性显著低于其他各组(P<0.05),各组间虾肌肉内聚力无差异统计学意义(P>0.05)。随着饲料蛋白质水平的增加,克氏原螯虾的肌肉粗蛋白含量呈先升高后趋于稳定的变化趋势,饲料蛋白质水平为35.31%、37.57%组虾的肌肉粗蛋白含量显著高于饲料蛋白质水平最低组(P<0.05);各组间虾的肌肉水分、粗脂肪、灰分含量差异不具统计学意义(P>0.05)。肌肉总氨基酸、总必需氨基酸、总非必需氨基酸以及亮氨酸、赖氨酸、天门冬氨酸、谷氨酸随饲料蛋白的升高均呈先升高后趋于稳定的变化趋势。综合考虑生长性能、肌肉品质以及成本效益,建议克氏原螯虾饲料蛋白质水平为30.09%。

Effects of dietary protein levels on growth performance and muscle quality of red swamp crayfish,procambarus clarkii

To investigate the effects of dietary protein levels on growth performance and muscle quality of Procambarus clarkii, they(initial body weight of red swamp crayfish: 3.69 ± 0.05 g) were randomly divided into 5 groups and fed different protein content diets(27.72%, 30.09%, 33.05%, 35.31% and 37.57%, respectively) for47 days. The results showed that the WGR and SGR of P. clarkii were firstly increased and then decreased with dietary protein level increased, and the WGR and SGR in dietary protein level 30.09% group were significantly higher than those in other groups(P<0.05). Muscle hardness and chewiness in dietary protein level 27.72% group were significantly higher than those in dietary protein level 35.31% and 37.57%(P<0.05). Muscle springiness in dietary protein level 30.09% and 33.05% groups were significantly higher than that in the lowest dietary protein level group(P<0.05). Muscle resilience in the highest dietary protein level group was significantly lower than that in other groups(P<0.05). Muscle crude protein of P. clarkii was firstly increased and then tended to stabilize with dietary protein level increased, and muscle crude protein in dietary protein level 35.31% and 37.57% groups were significantly higher than that in 27.72% group(P<0.05). Muscle WTAA, WEAA, WNEAA and Leu, Lys, Asp,Glu showed the same trend as muscle protein. While there was no significant difference in FCR, W/L, HIS, M,SR and muscle cohesiveness, moisture, crude fat, ash among all experimental groups(P>0.05). In conclusion, the suitable dietary protein level of P. clarkii was 30.09% based on the growth performance, muscle quality and costeffectiveness.