双低菜粕替代豆粕对青鱼幼鱼生长及生理生化指标的影响

以初始体重(5.77±0.05)g 的青鱼(Mylopharyngodon piceus)为研究对象, 以双低菜粕蛋白分别替代饲料中 0 (对照)、25%、50%、75%和 100%的豆粕蛋白, 配制双低菜粕含量分别为 0、11%、22%、33%和 44%的5 种等氮等能的实验饲料, 研究双低菜粕对青鱼生长、消化酶、消化率、体组成和部分生理生化指标的影响。实验在室内养殖系统中进行, 每水族箱(300 L)饲喂 25 尾, 每处理组 3 个重复, 以鱼体重 3%—5%投喂量, 日投喂 2 次, 试验持续 8 周。实验结果表明, 当饲料中双低菜粕含量大于 11%时, 其特定生长率、干物质和蛋白质表观消化率、肠道蛋白酶、淀粉酶和脂肪酶活性均显著低于对照组, 当双低菜粕含量达到 44%时, 饲料系数显著高于对照组(P<0.05), 但各处理间成活率差异不显著。双低菜粕对血清溶菌酶、谷丙转氨酶活性和补体 C4 含量无显著影响, 但显著影响了血液中红细胞和白细胞数, 其数量随饲料菜粕含量的增加而降低。与对照组相比, 当双低菜粕含量达到 22%时, 血清中总胆固醇、补体 C3 和总蛋白含量显著下降, 当含量达到 33%时, 过氧化氢酶活性显著降低, 谷草转氨酶活性显著升高(P<0.05)。饲料菜粕对鱼体水分和蛋白含量无显著影响, 但鱼体脂肪随菜粕含量的增加而降低、脏体比指数和灰分含量有随菜粕含量的增加而升高的趋势, 肝体比指数有随菜粕含量的增加而有先升高后降低的趋势。上述结果表明, 青鱼幼鱼饲料中双低菜粕含量以不超过 11%为宜。

INFLUENCE OF DIETARY CANOLA MEAL LEVELS ON GROWTH AND BIOCHEMICAL INDICES IN JUVENILE MYLOPHARVNGODON PICEUS

An 8-week feeding experiment was conducted to evaluate the effect of dietary canola meal(CM) levels on growth,feed utilization and some blood physiological-biochemical indices in juvenile black carp initial average weight of(5.77 ± 0.05) g].The inclusion levels of CM were 0(control),11%,22%,33% and 44%,to replace 0,25%,50%,75% and 100% of soybean meal(SBM),respectively.Each diet was randomly fed to triplicate groups of 25 fishes per tank(300 L).Fish were fed twice daily by hand at a rate of 3% –5% of body weight during eight weeks.The results showed that fish fed the diet with CM levels more than 11% showed relatively lower SGR,the activities of protease,amylase,lipase in intestine and apparent digestibility coefficients of dry matter and protein than those fed the control diet(P<0.05),however,no significant differences in survival were observed among dietary treatments.LSZ,C4 and ALT in serum were not affected by dietary levels of CM,but the number of RBC and WBC in blood significantly decreased with increasing of dietary CM levels(P<0.05).Fish fed the diet with CM levels up to 22% showed lower serum total cholesterol(TC),C3 and total protein(TP) concentration than those fed the control diet(P<0.05);Fish fed the diet with CM levels up to 33% showed lower serum CAT activity than those fed the control diet(P<0.05),AST in serum were significantly higher in fish fed diets with CM level up to 33% and 44% levels than those fed control diet.No significant differences in body moisture and protein contents were observed among dietary treatments.Declining body lipid content and increasing body ash content were observed with increasing dietary CM level.The VR increased with the increasing dietary CM level and HSI first significantly increased and then reduced.Based on these observations above,more than 11% dietary CM level could decrease growth,immunity and liver function for juvenile black carp.