团头鲂对饲料中Zn的需求量

为了研究团头鲂对饲料中Zn的需要量,以平均体质量50 g的团头鲂为实验对象,采用半纯化饲料,以ZnSO4·H2O为锌源,设置Zn添加量分别为0、68、137、206、275 mg/kg(饲料中Zn总量为22.85、98.07、164.00、235.43、307.96 mg/kg)共5个Zn含量梯度,每个实验组设4个平行,在池塘网箱中养殖43 d。经过回归拟合分析,饲料中Zn添加量、饲料中Zn总量与团头鲂特定生长率、饲料系数、蛋白质沉积率、脂肪沉积率的关系,得到团头鲂对饲料中无机Zn补充量为155.86~161.25 mg/kg,对饲料总Zn需要量为184.85~190.39 mg/kg;在日均摄食量为5.12 g/100 g体质量下,团头鲂对饲料Zn日需求量为0.798~0.825 mg/100 g体质量,对饲料总Zn日需要量为0.946~0.974 mg/100 g体质量。饲料中Zn含量对团头鲂的成活率、肥满度、内脏指数、鳞片重/体质量、体质量/体长、脊椎骨重/体质量无显著影响(P0.05)。饲料中Zn含量对团头鲂的脊椎骨长/体长有显著影响(P0.05);饲料中Zn的补充,有利于团头鲂脊椎骨的生长。

Dietary Zn requirement of Megalobrama amblycephala

In order to estimate the dietary Zn requirement of blunt snout bream(Megalobrama amblycephal),Five experimental diets containing different Zn contents of 0,68,137,206,275 mg/kg(total Zn of feed was 22.85,98.07,164.00,235.43,307.96 mg/kg)were for mulated with ZnSO₄·H₂O as the Zn source.A total of 400 blunt snout bream with an initial body weight of 50 g were randomly divided into 5 groups with 4 replicates per group and 20 blunt snout bream per replicate.Each group of fish was fed two diet for 43 days.The results showed as follows:Through regression analysis of relationship between the amount of Zn added to feed,the total Zn of the feed and the SGR,FCR,protein deposition rate,fat deposition rate of the blunt snout bream,when the Zn supplement in the feed was 155.86-161.25 mg/kg(the actual Zn content was 184.85-190.39 mg/kg),blunt snout bream has the best growth performance.In this experiment,the daily feed intake of blunt snout bream was 5.12 g/100 g body weight/d,so the added Zn content of the feed in the 0.798-0.825 mg/100 g weight/d(the total Zn content of the feed was 0.946-0.974 mg/100 g weight/d),blunt snout bream can achieve the maximum growth.The survival rate,fatness,viscera index,scale weight/body weight,body weight/body length,vertebral bone weight/body weight were not significantly affected by dietary Zn content(P>0.05).But in the 0 mg/kg group,vertebral bone length/body length was significantly lower than the 137 mg/kg group(P<0.05);Supplement of Zn is conducive to the growth of the spine of blunt snout bream.