Preparation Of Porcine Hemoglobin Polypeptide Chelated Iron And Its Application In The Diet Of Weaned Piglets

In this paper,porcine hemoglobin polypeptide chelating iron was prepared from fresh pig blood by separation,wall breaking,enzymatic hydrolysis,chelation,sterilization,drying and other processes.The optimization of protease hydrolysis process was studied.The effects of different levels of porcine hemoglobin polypeptide chelating iron on production performance and blood physicochemical indexes of weaned piglets were studied,It provides a reference for the accurate and reasonable application of the product in pig breedingAlkaline protease,special enzyme for blood protein hydrolysis,acid protease,neutral protease and pepsin were selected to hydrolyze porcine hemoglobin.The protease suitable for industrial production was selected with the extraction rate of hydrolyzed polypeptide as the index.Then the single factor enzymatic hydrolysis conditions of pH,temperature,enzyme dosage and hydrolysis time were compared,and the differences were compared by single factor analysis of variance.A total of 192 42 day old weaned piglets(average body weight 10.49±0.06 kg)were randomly divided into 4 groups,with 4 replicates in each group and 12 piglets in each replicate;the control group was fed with basic diet,and the experimental diets supplemented with 700,900 and 1200 mg/kg porcine hemoglobin polypeptide chelating iron in the basic diet were fed in the test groups 1,2 and 3.The experimental period was 31 days,the adaptation period was 3 days,and the trial period was 28 daysThe results showed that:(1)The protease suitable for industrial production was alkaline protease.The optimized conditions of 10.08%substrate concentration porcine hemoglobin solution were pH of 10.0,temperature of 55?,enzyme dosage of 1.5%(by weight of blood cell)and hydrolysis time of 10 h.(2)After chelating with ferrous chloride,porcine hemoglobin polypeptide forms porcine hemoglobin polypeptide chelating iron which is insoluble in ethanol.The chelating force of iron is 99.46±0.19%.(3)Preparation of porcine hemoglobin polypeptide chelating iron component:the content of iron,crude protein,acid soluble protein/crude protein,ash content and moisture content was 1.26%,83.36%,55.43%,7.69%and 2.52%.(4)From the whole period of the experiment,the ADG and ADFI of test group 1 and 2 were significantly higher than those of control group(P<0.05),and the F/G of test group 2 was significantly lower than that of control group and test group 1(P<0.05).(5)On the 14th day of the experiment,the content of hemoglobin(Hgb)in the test group 2 was significantly higher than that in the other groups(P<0.05),and the hematocrit(HCT)was significantly higher than that in the control group(P<0.05);on the 28th day of the experiment,the content of HGB in the test group 2 was significantly higher than that in the control group(P<0.05).(6)The content of serum ferritin(FN)increased with the increase of dietary porcine hemoglobin polypeptide chelating iron level on the 14th day(P=0.067),and the content of FN in the serum of weaned piglets in test 2 and test 3 groups was significantly higher than that in the control group(P<0.05).(7)On the 14th day,the serum immunoglobulin G(IgG)content of test group 1 was the highest,which was significantly higher than that of control group and test group 3(P<0.05),and had no significant difference with test group 2(P>0.05).On the 28th day,there was no significant difference in serum IgG content among the groups(P>0.05).(8)During the experiment,dietary supplementation of different levels of porcine hemoglobin polypeptide chelating iron had no significant effect on serum triglyceride,alanine aminotransferase,glutamic oxalacetic transaminase,total protein,albumin,calcium and alkaline phosphatase(P>0.05).(9)Compared with the control group,the fecal score of the test group 2 and 3 was improved,but the difference was not significant(P>0.05).There was no significant difference in the fur appearance of weaned piglets among groups(P>0.05).It can be seen that adding appropriate amount of porcine hemoglobin polypeptide chelating iron in the diet of weaned piglets can significantly improve their production performance and iron nutritional status,and improve the immunological function of weaned piglets to a certain extent.The appropriate adding level is 700?900 mg/kg,which depends on the weaning age and iron nutritional status of piglets.