紫花苜蓿浓缩叶蛋白替代鱼粉对星斑川鲽氮磷排泄的影响

Effects of dietary fishmeal replacement by alfalfa protein concentration on nitrogen and phosphorus excretion in juvenile starry flounder

本研究以体重为(83.0±0.20)g星斑川鲽幼鱼为试验对象,研究紫花苜蓿浓缩叶蛋白(APC)替代0%(S0)、10%(S10)、20%(S20)、30%(S30)、40%(S40)、50%(S50)的鱼粉对其氮磷排泄的影响。结果显示:各试验组氮摄入量、氮沉积率均呈先稳定后显著下降的趋势。氮排泄量与氮沉积率变化趋势相反,当鱼粉替代水平>30%时显著上升(P<0.05)。磷摄入量与磷排放量均呈显著下降趋势(P<0.05),磷沉积率呈上升趋势(P<0.05)。与对照组相比,可溶性磷酸盐排泄量随APC替代鱼粉量的增加呈下降趋势(P<0.05)。综合上述试验结果,从保护养殖水体的角度出发,APC替代鱼粉蛋白的比例应控制在30%以内。

The experiment was conducted to study the effects of fishmeal substitution with alfalfa protein concentrate （APC） on nitrogen and phosphorus excretion of juvenile starry flounder （Platichthys stellatus）.Six isonitrogenous and isoenergetic diets were formulated,in which fishmeal protein was replaced by alfalfa protein concentrate （APC） at 0% （S0）, 10% （S10）, 20% （$20）, 30% （$30）, 40% （S40）and 50% （$50）, respectively.The results showed that ：nitrogen intake and nitrogen retention content remained constant,and then decreased with increasing level of ACP.Nitrogen load was changed with the opposite tendency ,and increased when the substitution level was higher than 30%（P 〈 0.05 ）.Phosphorus intake and load were all decreased,while phosphorus retention increased by dietary APC substitution（P 〈 0.05）.Compared to the control group （SO）,PO4-P content was reduced significantly （P 〈 0.05）.The experiment indicated that APC could significantly affect the nitrogen and phosphorus excretion of starry flounder, and considering from the scope of water pro- tection, the substitution level should be limited within 30%.