Study On The Law Of Releasing Small Molecular Peptides From Protein Feedstuffs Digested In Broilers

The unique absorption mechanism of small molecular peptides(2～3 peptides) and discovery of small peptide transporters proved that small molecular peptides had important status in protein theory. The therapy studied the law of releasing small molecular peptides of seven protein feedstuffs which were digested by broilers in vitro and in vivo.Experiment 1 Study on the law of releasing small molecular peptides of protein feedstuffs digested by simulating the gastrointestine environment of broiler in vitroIn this test, seven kinds of raw materials such as rapeseed meal, cottonseed meal, soybean meal, peanut meal, casein protein, blood meal and fish meal were hydrolyzed in vitro by simulating the environment of 21-day-old broiler crop, stomach and small intestine to study the law of digestibility and releasing small peptides (molecular weight <600 Da) of protein feedstuffs. The results showed that the digestibility of the seven protein feedstuffs in vitro from large to small were casein protein (89.05%), fish meal (87.20%), soybean meal(84.78%), peanut meal (83.84%), cottonseed meal (69.36%), rapeseed meal (67.51%) and blood meal (45.19%). The percentage of releasing small peptides (molecular weight <600 Da) from large to small were as follows:casein protein (21.51%), fish meal (17.66%), blood meal (13.82%), soybean meal(8.15%), peanut meal (7.40%), cottonseed meal ( 7.02%) and rapeseed meal (6.60%).Experiment 2 Study on the law of releasing small molecular peptides of protein feedstuffs in vivoThirty-five broilers aged 21 days old were divided into seven treatment groups randomly. Each broiler was force-fed 30g feed which contained 70% feedstuff (rapeseed meal, cottonseed meal, soybean meal, peanut meal , blood meal and casein protein) and 30% starch.to study the characteristics of releasing small molecular peptides (<600Da) of protein feedstuff in the various digestive tract, and qualitatively study the law of secretion and absorption of small molecular peptides of protein feedstuff in the digestive tract. The results showed that percentage of small molecular peptides in soluable protein which the same protein feedstuff released varied significantly. Significant difference was found between different feedstuffs. The descendent sequence of the percentage was soybean meal, peanut meal, casein protein, cottonseed meal, fishmeal, rapeseed meal and blood meal. The law of the small molecular peptides release and absorption of the seven protein feedstuffs was different in the small intestine. With the exception of cottonseed meal and peanut meal, the law of the other five protein feedstuffs was: the absorption in the small intestine forepart was larger than in the posterior segment.