仿生法评定几种猪常用植物性饲料原料磷体外透析率

摘要

本试验通过比较不同截留分子质量(MWCO)透析袋条件下几种饲料原料的总磷与无机磷体外透析率,探讨采用SDS-Ⅰ型仿生消化系统进行饲料磷体外透析率快速测定的可行性.试验1通过测定玉米、豆粕和麦麸的仿生消化残渣中总磷及透析液中无机磷含量,研究MWCO 分别为14000和3500u的透析袋分离无机磷与有机磷的有效性,探讨消化残渣总磷测定法评定饲料磷体外透析率的可行性.试验2通过测定仿生消化透析液中无机磷含量,分别评定MWCO为14000和3500 u透析袋条件下玉米、豆粕、米糠、菜籽粕及麦麸磷的体外透析率,探讨透析液无机磷测定法评定饲料磷体外透析率的可行性.结果表明:1)2种透析袋条件下消化残渣总磷测定法测得透析液中均存在有机磷,表明MWCO3500u透析袋仍然没有将有机磷完全截留,没有达到有机磷与无机磷有效分离的目的.2)MWCO14000u透析袋条件下,透析液无机磷测定法测得饲料磷体外透析率结果显著高于MWCO3500u透析袋条件下测定结果(P＜0.05).3)仿生消化法测得饲料磷体外透析率的变异系数均在4％以下,低于其他研究者报道的结果.综上所述,MWCO3500 u透析袋无法实现饲料中无机磷与有机磷的有效分离,因此消化残渣总磷测定法不适用于饲料磷体外透析率的研究；MWCO14000u透析袋条件下透析液无机磷测定法,试验测值和精度都较高,更适宜于仿生法评定饲料磷体外透析率的研究.%The total phosphorus dialyzability and inorganic phosphorus dialyzability of several feed ingredients determined using different molecular weight cutoff ( MWCO) dialysis tubings (DT) were investigated for tes-ting whether bionic digestive system could be used for determining phosphorus in vitro dialyzability. The total phosphorus in undigested residue and inorganic phosphorus in dialysate was determined in experiment 1, which was to study whether MWCO 14 000 or 3 500 u DT could separate inorganic phosphorus and organic phosphor-us. In experiment 2, the phosphorus in vitro dialyzability of swine common feed ingredients (corn, soybean meal, rice bran, rapeseed meal and wheat bran) was measured by determining inorganic phosphorus in dialy-sate using MWCO 14 000 or 3 500 u DT, which was to study the feasibility of using inorganic phosphorus de-termination to measure phosphorus in vitro dialyzability. The results showed as follows: 1) there was organic phosphorus in dialysate, which indicated that MWCO 3 500 u DT was unable to separate inorganic phosphorus and organic phosphorus. 2) In inorganic phosphorus determination experiment, the phosphorus in vitro dialyz-ability determined using MWCO 14 000 u DT was significantly higher than that determined using 3 500 u DT (P<0.05). 3) The coefficients of variation of the phosphorus dialyzability in the experiment of inorganic phosphorus determination were all less than 4% , which was lower than the results reported by other research-ers. In conclusion, MWCO 3 500 u DT is unable to separate inorganic phosphorus and organic phosphorus, so the phosphorus in vitro dialyzability can not be measured by determining the total phosphorus in undigested resi-due; the results of inorganic phosphorus determination using MWCO 14 000 u DT is higher and accurate, so the method is more appropriate for measuring phosphorus in vitro dialyzability of feed ingredients for pigs.