密度、饲料配比和投饲频率对菲牛蛭成活和生长的影响

Effects of Stocking Density,Feed Formulation and Feeding Frequency on Survival and Growth in Leech Poecilobdella manillensis

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≥1.5g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15d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10d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10d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 each35.0cm ×14.5cm ×11.5cm with moist soil bottom at a depth of 6.0cm and effects of stocking density,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 factors on survival of the leech was ranged as stocking density〉feeding frequency〉feed formulation,the maximal survival rate under the conditions of dietⅡ,feeding once every 15 days,and at density of 50 individuals per net cage.The descendant order of effect of the three factors on growth of the leech was described as feed formulation〉feeding frequency〉stocking density,the best growth under the conditions of dietⅠ,feeding once every 10 days,and at density of 50 individuals per net cage.According to the orthogonal 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 dietⅠ,feeding once every 10 days,and at density of 50 individuals per net cage.