饼粕类饲料蛋白质降解率的研究

ESTIMATION OF FEED PROTEIN DEGRADATION RATE IN THE RUMEN OF SHEEP

５头带瘤胃和真胃瘘管的绵羊饲喂由基础饲料和蛋白质补充料豆饼、芝麻粕、大豆粕、花生粕、处理豆饼、黄豆粉组成的日粮，用体内法测得７种日粮的蛋白质瘤胃降解率（％）分别为６７．８９、６９．８２、６６．５６、７０．７０、６３．０３、７２．１７、８０．０５；相应蛋白质补充料的降解率（％）为４８．３３、４９．１８、５１．２６，６０．７７、３１．７０、６８．２２。用尼龙袋法估测上述蛋白质补充料的蛋白质降解率（Ｋ＝０．０３３）分别为（％）７５．７７、６６；３６、６７．６４、７５．１２、３５．５１、９０．２５；饼粕饲料蛋白质体内法测定的降解率与尼龙袋法估测的结果相关关系为：Ｙ＝７．９５＋０．６５×（ｒ＝０．９４，ｎ＝６，Ｐ＜０．０１）。

Five sheep,fitted with a rumen fistula and abomasum fistula were fed with sevendiets consisting of basal dietary and protein supplement of soybean meal (diet SBM),sesame cake(diet SC),soybean cake (diet SBC),groundnut cake(diet GNC),heatedsovbean meal (diet HSBM), ground whole soya bean (diet GWSB) and casein (diet C),Diet C was controll diet.Chromic oxide and polyethylene glycol (PEG) were given asmarkers and the digesta samples were taken both from the rumen and abomasum.Based on RNA as microbial marker,results showed that rumen degradation rate oftotal dietary protein were 67.89%, 69.82%, 66.56%, 70.70%, 63.03%,72.17%and81.05%for diet SBM,SC,SBC,GNC,HSBM,GWSB and C respectively.The proteindegradtion rate of SBM,SC, SBC,GNC,HSBM,GWSB were 48.33%,49.18%,51.26%,60.77%,31.70%and 68.22% respectively.Protein supplements degradationrate obtained by nylon bag technique(k=0.033)for SBM,SC,SBC, GNC,HSBM,GWSB were 75.77%,66.36%,67.64%,75.12%,35.5l%and 90.25%,respectively.The relatlonship between the degradation rate by in vivo method and that by nylon bagtechnique was:Y=7.95+0.64X(r=0.94,n=6,P<0.01).