Rutherfurd S M, Moughan P J
Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand.
J Anim Physiol Anim Nutr (Berl). 2003 Aug;87(7-8):292-300. doi: 10.1046/j.1439-0396.2003.00438.x.
The growing pig is an established model animal for humans to determine protein digestibility to the end of the small intestine. An ileal amino acid digestibility assay based on the laboratory rat offers an alternative. True ileal amino acid digestibility in high quality refined protein sources was determined and compared between the laboratory rat and the growing pig. Both species of animals were fed their daily ration in nine separate meals. Ileal digesta were collected at slaughter and chromic oxide was used as an indigestible marker. For several of the amino acids examined, there were no significant (p < 0.05) differences between the two species for true ileal amino acid digestibility, but for aspartic acid, serine, cysteine, methionine, tyrosine, phenylalanine and histidine, significant (p < 0.05) interspecies differences were found. The overall average amino acid digestibility, for all amino acids and all diets, was 95.8% for the pig and 96.1% for the rat. Cysteine digestibility was highly variable between individual animals fed the same diet. The extent of amino acid digestion and absorption appears to be broadly similar across the two species, but some important differences in digestibility were recorded.
生长猪是人类确定小肠末端蛋白质消化率的一种成熟的模式动物。基于实验大鼠的回肠氨基酸消化率测定法提供了一种替代方法。测定并比较了实验大鼠和生长猪对优质精制蛋白质来源的真回肠氨基酸消化率。两种动物均分九餐喂食其每日定量饲料。屠宰时收集回肠食糜，氧化铬用作不可消化标记物。在所检测的几种氨基酸中，两种动物的真回肠氨基酸消化率无显著（p < 0.05）差异，但天冬氨酸、丝氨酸、半胱氨酸、蛋氨酸、酪氨酸、苯丙氨酸和组氨酸存在显著（p < 0.05）种间差异。所有氨基酸和所有日粮的总体平均氨基酸消化率，猪为95.8%，大鼠为96.1%。喂食相同日粮的个体动物之间，半胱氨酸消化率差异很大。两种动物的氨基酸消化和吸收程度似乎大致相似，但记录到了一些重要的消化率差异。
