密度、饲料配比和投饲频率对菲牛蛭成活和生长的影响

摘要

采用湿土网箱法，在内铺土层厚度约6．0cm，规格35．0cm×14．5cm×11．5cm的网箱中层，饲养体质量≥1．5 g的菲牛蛭，以存活率和个体体质量增长率为考察指标，采用L9（34）正交试验法，对养殖密度、饲料配比和投饲频率三个因素进行考察，以确定合理的养殖密度、饲料配比和投饲频率。采用层次分析法统计正交试验结果，分析各因素各水平对试验结果的影响权重。试验结果表明，以存活率为考察指标时，三种因素对成活率的影响依次为养殖密度＞投饲频率＞饲料配比，以50尾／箱的养殖密度，饲料配方Ⅱ和每15 d投喂一次的投饲频率组合为最佳；以菲牛蛭个体体质量增长率为考察指标时，三种因素对个体体质量增长率的影响依次为饲料配比＞投饲频率＞养殖密度，投喂以密度为50尾／箱、饲料配方为Ⅰ、投喂频率为每10 d投喂一次组合为最优。层次分析表明，各因素对正交试验的指标值影响的主次顺序为养殖密度、投饲频率和饲料配比，正交试验的最优方案为50尾／箱的养殖密度、配方Ⅰ和每10 d投喂一次的投饲频率。%Leech Poecilobdella manillensis with body weight of over 1. 5g were reared in net cages of each 35 .0 cm × 14 .5 cm × 11. 5cm with moist soil bottom at a depth of 6 .0 cm and effects of stocking densi-ty ,feed formulation and feeding frequency on survival and growth in the leech were investigated by a L9 (34 ) orthogonal test .AHP statistical analysis revealed that the descendant order of effect of the three fac-tors on survival of the leech was ranged as stocking density > feeding frequency > feed formulation ,the maximal survival rate under the conditions of diet Ⅱ ,feeding once every 15 days ,and at density of 50 indi-viduals per net cage .The descendant order of effect of the three factors on growth of the leech was de-scribed as feed formulation > feeding frequency > stocking density ,the best grow th under the conditions of diet Ⅰ ,feeding once every 10 days ,and at density of 50 individuals per net cage .According to the or-thogonal test ,the descendant order of effect of the three factors on survival and growth of the leech was expressed as stocking density > feeding frequency > feed formulation ,the best under the conditions of di-et Ⅰ ,feeding once every 10 days ,and at density of 50 individuals per net cage .