Study On Extracting Oligopeptides From Feed Resources And The Effects On The Immune Function Of Mice And The Growth Of The Rumen Microbes Of Sheep

This paper mainly studies on the optimal conditions extracting the immustimulative oligopeptides from Fishmeal and Soybean with Pepsin and Trypsin treatments respectively by Ultrafiltration and Ion exchange. In addition ,the effects of the different oligopeptides (MW less than 3000Da) on immune responses of mice and on the rumen microbial growth and the proteolytic and cellulylotic activity in the rumen of sheep has been investigated.Part 1: Studied on the procedures of extracting the active oligopeptides from hydrolysis of different feedstuffs. The results showed that the enzymatic hydrolysis of Fishmeal and Soybean was carried out at 37℃for 20h;the optimum pH was 2 and 7 when treated with Pepsin and Trypsin ,respectively.The extracted four kinds of different oligopeptides (molecular weight was less than 3000Da) were obtained from the treatments as follows:the Pepsin treated oligopeptide of fishmeal (P-Fishmeal oligopeptide); the Pepsin treated oligopeptide of Soybean (P-Soybean oligopeptide); the Trypsin treated oligopeptide of Fishmeal (T-Fishmeal oligopeptide); the Trypsin treated oligopeptide of Soybean (T-Soybean oligopeptide).Part 2: Studied on the effects of the four kinds of oligopeptides on the immune responses of miceThe four kinds of oligopeptide compounds were injected into the mice with different dosage as follows:0 mg/ml, 3mg/ml, 5mg/ml, 15mg/ml, 25mg/ml, 35mg/ml, 45mg/ml, 55mg/ml and 65mg/ml,and then the transformation efficiency of the T-lymphocty was determined.The assay results showed that (1) the transformation efficiencies of the T-lymphocyte on the 7th day was not enhanced; There were significant differences of the transformation efficiency of the T-lymphocyte on the 14th day between the control(0mg/ml) and treatment groups; (2) The transformation efficiencies of T-lymphocyte between P-Soybean oligopeptide treated and control groups were different significantly(P<0.05), the highest transformation efficiency of the T-lymphocyte in the treatment groups was increased by 37.93%; (3)when injected the P-Fishmeal oligopeptide with 35mg/ml dosage, T-lymphocyte counts were multiplied;at the dosage of 65mg/ml , the transformation efficiency of the T-lymphocty reached highest level and increased by 40.93%; (4)Injection of the T-Soybean oligopeptide with 35mg/ml dosage increased the transformation efficiency of T-lymphocyte,which was increased by 36.59%; (5)For T-Fishmeal oligopeptide, The 35mg/ml dosages also had the same immune response,and the highest transformation efficiency was 21.41%.Part 3: Studied on the effects of four kinds of different oligopeptides from different N sources on the growth of ruminal microbes and the proteolytic activity and cellulylotic enzyme activity in vitro. The results showed:(1) the rumen microbial growth was promoted by oligopeptides,addition,it was found that the oligopeptides from animal feedstuff was better than that from plant feedstuff(2) the fishmeal oligopeptides and the soybean oligopeptides could instimulate the growth rates and increase the counts of bacteria and protozoa in the rumen;(3) the fishmeal oligopeptides and the soybean oligopeptides could promote the activity of rumen proteinase but they had no effect on the cellulylotic enzyme activity.(4) the N supplied by the oligopeptide were better than the other N sources compared with stimulation of the rates of the rumen microbial growth.