14~35日龄北京鸭25-羟基维生素D_(3)与维生素D_(3)需要量及其相对生物学效价的研究

Requirement and Relative Bioefficacy of 25-Hydroxyvitamin D 3 and Vitamin D 3 of Pekin Ducks from 14 to 35 Days of Age

本试验旨在研究饲粮添加不同形式和不同水平的维生素D对14~35日龄北京鸭生长性能和血浆生化指标的影响,以确定北京鸭25-羟基维生素D3(25-OH-D3)与维生素D3的需要量及其相对生物学效价。试验选取728只14日龄健康且体重相近的雄性北京鸭,随机分为13个组,每组8个重复,每个重复7只鸭。试验设1个基础饲粮组(不添加维生素D),6个25-OH-D3添加组和6个维生素D3添加组,添加水平均为100、200、400、800、1200和2000 IU/kg。试验期为3周。结果表明:1)与基础饲粮组相比,饲粮中添加维生素D3对14~35日龄北京鸭生产性能并无显著影响(P>0.05),而饲粮中添加25-OH-D3可显著提高北京鸭平均体重(BW)和平均日增重(ADG)(P<0.05)。2种形式维生素D组间的生产性能无显著差异(P>0.05)。2)与基础饲粮组相比,饲粮中添加维生素D3或25-OH-D3均显著降低35日龄北京鸭血浆碱性磷酸酶(ALP)活性(P<0.05),显著提高血浆钙含量(P<0.05),而2种形式维生素D组间并无显著差异(P>0.05),但是维生素D的形式与饲粮维生素D水平存在显著交互作用(P<0.05)。3)随着维生素D3或25-OH-D3添加水平的增加,血浆中25-OH-D3含量均呈显著线性增长(P<0.01)和二次曲线变化(P<0.01),且维生素D的形式与饲粮维生素D水平存在显著交互作用(P<0.05),25-OH-D3添加组血浆中25-OH-D3含量显著高于维生素D3添加组(P<0.05)。4)以血浆ALP活性和钙含量为评价指标,采用二次曲线-折线模型估测14~35日龄北京鸭维生素D3的需要量分别是440.7和100.0 IU/kg,25-OH-D3的需要量均为100.0 IU/kg。5)以血浆ALP活性和25-OH-D3含量为评价指标,采用指数模型估测14~35日龄北京鸭25-OH-D3的生物学效价分别为维生素D3的2.16和2.37倍。综上所述,饲粮中添加维生素D3或25-OH-D3均可提高血浆中钙和25-OH-D3含量,降低ALP活性;但饲粮中添加25-OH-D3对于血浆中25-OH-D3沉积效率更高,并可提高肉鸭生产性能。

This experiment was conducted to investigate the effects of different forms and levels of dietary vitamin D on growth performance and plasma biochemical indices of Peking ducks aged 14 to 35 days to determine the requirements of 25-hydroxyvitamin D 3(25-OH-D 3)and vitamin D 3 and their relative bioefficacy.A total of 728 healthy male Peking ducks at 14 days of age with similar body weight were randomly divided into 13 groups with 8 replicates per group and 7 ducks per replicate.One basal diet group(without vitamin D),six 25-OH-D 3 supplemental groups and six vitamin D 3 supplemental groups were set up,and the supplemental levels were 100,200,400,800,1200 and 2000 IU/kg.The trial lasted for 3 weeks.Results showed as follows:1)compared with the basal diet group,dietary vitamin D 3 supplementation had no significant effects on the growth performance of Pekin ducks aged 14 to 35 days(P>0.05),but dietary 25-OH-D 3 supplementation significantly increased the average body weight and average daily gain(P<0.05).However,there was no significant difference in growth performance between the two supplemental forms of vitamin D(P>0.05).2)Compared with the basal diet group,dietary supplementation of vitamin D 3 or 25-OH-D 3 significantly decreased the plasma alkaline phosphatase activity(P<0.05),and significantly increased the plasma calcium content(P<0.05)of Pekin ducks at 35 days of age.However,there was no significant difference between the two groups(P>0.05),and there was a significant interaction between the two forms and dietary vitamin D levels(P<0.05).3)With the increase of vitamin D 3 or 25-OH-D 3 supplemental levels,the plasma 25-OH-D 3 content showed a significant linear increase and quadratic change(P<0.01),and there was a significant interaction between the two forms and dietary vitamin D levels(P<0.05).Moreover,the plasma 25-OH-D 3 content in the 25-OH-D 3 supplemental group was significantly higher than that in the vitamin D 3 supplemental group(P<0.05).4)Using plasma alkaline phosphatase activity and calcium content as evaluation indexes,the quadratic curvilinear model was used to estimate that the vitamin D 3 requirement of Pekin ducks aged 14 to 35 days was 440.7 and 100.0 IU/kg,respectively,and the 25-OH-D 3 requirement was 100.0 IU/kg.5)Using plasma alkaline phosphatase and 25-OH-D 3 content as evaluation indexes,the relative bioefficacy of 25-OH-D 3 in Pekin ducks aged 14 to 35 days was estimated to be 2.16 and 2.37 times that of vitamin D 3 by the index model.In conclusion,dietary supplementation of vitamin D 3 or 25-OH-D 3 can increase plasma calcium and 25-OH-D 3 contents,as well as reduce alkaline phosphatase activity;however,dietary supplementation of 25-OH-D 3 has a higher deposition efficiency of 25-OH-D 3 in plasma and can improve the growth performance of meat ducks.