十二指肠灌注饲料寡肽对鸡肠道氨基酸吸收的影响

Effects of duodenual infusion of feed peptides on portal absorption of amino acids in chickens

关键词:  十二指肠灌注 饲料 寡肽 鸡 肠道 氨基酸 能量吸收 影响因素

Key words:  chickens,feed oligo peptide,duodenal infusion,intestinal absorption,portal FAA

摘要:

用十二指肠灌注法在不麻醉状态下研究饲料寡肽对鸡肠道氨基酸吸收的影响。灌注用寡肽分别是 4种常规饲料 (鱼粉、豆粕、棉粕、菜粕 )体外酶水解产物的 2组低分子量组分 ( <3kD和 <1kD)。试验 1:十二指肠灌注豆粕 <3kD寡肽 (S3)后 ,测定不同时间肝门静脉血浆游离氨基酸 (FAA)浓度 ,结果表明 ,灌注后总FAA浓度迅速上升 ,2 0min时最高。试验 2 :采用吸收强度和吸收平衡系数作为评价肠道氨基酸吸收效率的指标 ,比较十二指肠灌注 8种饲料寡肽后 2 0min时的氨基酸吸收效率。结果表明 ,各种饲料 <3kD寡肽组的氨基酸吸收效率均显著高于其 <1kD组 (P <0 0 5 ) ;在同一种分子量寡肽组中鱼粉、豆粕寡肽组显著高于棉粕和菜粕寡肽组 (P <0 0 5 ) ;氨基酸吸收效率与灌注底物的寡肽含量 (PAA/TAA)存在显著正相关 (P <0 0 5 )。本研究结果显示 ,鱼粉、豆粕等优质蛋白质在动物胃肠道中产生较多寡肽 ,因而具有较高的氨基酸吸收效率

Abstract:

Two experiments were conducted using duodenal infusion method to investigate the effect of feed oligo peptides on portal absorption of amino acids in chickens under unanesthetized condition. The oligo peptides used in experiments were enzymatic hydrolysates of fish meal, soybean meal, cottonseed meal and rapeseed meal with the average molecular weight of <3kD and <1kD. Experiment 1: Portal Blood were collected at different minute after administration of enzymatic hydrolysate of soybean meal with the average molecular weight <3kD (S3). Plasma concentrations of free amino acids (FAA) were measured. The results showed that total plasma FAA concentrations immediately increased and reached maximum level at 20 min after infusion. Experiment 2: Absorptive intensity and balance were used to estimate the intestinal absorption rate of amino acids. FAA concentrations of portal blood at 20 min after duodenal administrations were determined. Amino acid absorption rates of eight infusion groups were compared. Results showed that amino acid absorption rates of <3kD groups were significantly higher than those of <1kD groups; Absorption rates of fish meal and soybean meal groups were markedly higher than those of cottonseed meal and rapeseed meal groups among <3kD groups or <1kD groups; There existed positive correlation between absorption rates and proportions of peptide bound amino acids (PAA) in infused substrates. The results of this investigation suggest that the fish meal and soybean meal are hydrolyzed into more oligo-peptides in animal gastrointestinal tract and consequently utilized more effectively by body tissues and had higher nutritive value.