肉仔鸡体外消化模拟技术的研究

An in vitro Digestion Method for Broiler

【目的】本研究建立了一套能够模拟肉仔鸡嗉囊、胃(肌胃和腺胃)和小肠消化与养分吸收的体外消化模拟装置,并对其相关参数进行研究。【方法】通过测定体外养分消化率的方法,确定该装置透析液流速、透析袋截留分子量、饲料粉碎粒度和消化样品重量等适宜参数。【结果】粗蛋白和淀粉消化率随透析液流速的增加而增加,当透析液流速为2.0ml·min-1时的粗蛋白和淀粉消化率显著高于流速为1.0和1.5ml·min-1(P<0.01),但与2.5ml·min-1的流速间无显著差异(P>0.05)。透析袋截留分子量由1200～2000D增加到12000～14000D时,粗蛋白和淀粉体外消化率均显著提高(P<0.01)。饲料样品粉碎粒度由过40目降至过60目筛后,粗蛋白和淀粉体外消化率随之提高(P<0.05)。当饲料样品为1.5g时,粗蛋白和淀粉的体外消化率均显著低于0.5和1g(P<0.01),而测定样品重量为0.5和1g间均无显著差异(P>0.05)。经检验该装置粗蛋白和淀粉体外消化率变异系数均小于5%,稳定性较好。【结论】本研究所建立的肉仔鸡体外消化模拟装置适宜的透析液流速、透析袋截留分子量、饲料粉碎粒度和消化样品重量分别为2.0ml·min-1、12000～14000D、过60目和1g样品重。

[Objective] An in vitro digestion device, adopting continuous dialysis method, was devised to imitate the nutrients digestion and absorption in crop, gizzard and proventriculus and small intestine of broiler. The suitable parameters were studied too. [ Method ] The suitable parameters of buffer flow rate, dialysis tube molecular weight cutoff, particle size and weight of feed sample were made certain through determining nutrients in vitro digestibility. [Result] Crude protein （CP） and starch digestibility rise with buffer flow rate. When buffer flow rate is 2.0 ml.min^-1 both CP and starch digestibility is higher than when buffer flow rate is 1.0 ml.min^-1 and 1.5 ml.min^-1 respectively （P〈0.01）, but lower than 2.5ml.min^-1 （P〉0.05）. CP and starch digestibility were improved by increasing dialysis tube molecular weight cutoff from 12 000 to 14 000 D and decreasing feed sample particle size from No.40 sieve to No.60 sieve. Feed sample weight also affects on CP and starch digestibility in vitro. When 1.5 g feed sample digested in vitro CP and starch digestibility was lower than 0.5 g and 1 g （P〈0.01）, but there is no significant difference between 0.5 g and 1 g （P〉 0.05）. [Conclusion] The suitable buffer flow rate, size of dialysis tube molecular weight cutoff, particle size and weight of feed sample of this in vitro digestion device for broiler were 2.0 ml.min^-1, 12 000-14 000 D, 60 mu and 1 g respectively. The device shows a good stability and replication. Both of CP and starch digestibility coefficient of variation in vitro are below 5%.