Yao Kang

Extraction and identification of the chyme proteins in the digestive tract of growing pigs

This study aimed to explore the rule of degradation of dietary proteins by identifying chyme proteins in different segments of the digestive tract of growing pigs, using proteomics techniques. Six growing pigs were fed a corn-soybean meal-based diet for 7 days. The feedstuff and chyme proteins were separately extracted and separated with SDS-PAGE. 2D LCMS/MS combined with protein database searching identified 1,513 proteins in different segments of the gastrointestinal tract, the number of identified exogenous proteins gradually decline from the stomach to colon, with large amounts in the duodenum to the large intestine. More corn proteins than soybean proteins were identified both in the feedstuff and chyme, and these were significantly decreased after digestion in the stomach. More membrane proteins than non-membrane proteins were identified in whole digestive tract. These results regarding the profiles of chyme proteins in different segments of the gastrointestinal tract would provide useful information for optimizing feed formula in pigs.

饲粮添加α-酮戊二酸对生长猪氮及钙、磷代谢的影响

本试验旨在研究低蛋白质饲粮添加α-酮戊二酸（α-ketoglutarate，AKG）对生长猪氮以及钙、磷代谢的影响。试验选用初始体重为（34.98±2.18） kg的健康三元杂交（杜×长×大）猪18头，按体重相近、性别比例相同原则随机分为3组，每组6个重复，每个重复1头。各组AKG的添加水平分别为0（对照组）、1%和2%。先进行为期14 d的饲养试验，观察生长性能；然后进行消化代谢试验，试验期为7 d，前5 d为预试期，后2 d为粪尿收集期（全收粪法）。结果表明：1）1%AKG添加组有改善35～45 kg生长猪生长性能的趋势，具体表现为提高平均日增重（P=0.194 2）和平均日采食量（P=0.258 3），降低料重比（P=0.419 7）。2）随着AKG添加水平提高，尿氮含量有下降趋势（P=0.143 2），粪氮、总氮含量及总氮排放率极显著降低（P 0.05）。由此可见，在35～45 kg的生长猪饲粮中添加1%～2%AKG可有效降低机体氮、钙、磷排放，提高氮及钙、磷的利用率和日增重。