A Study On The Influence Of Porcine Intestine Hydrolysate On The Histological And Enzymatic Characteristic Of Small Intestine And On Immune Functions Of Weaning Pigs

The hydrolyzing conditions to produce porcine intestine hydrolysate (PIH) from a residue of heparin extraction were screened in the first part at this study. The safety of the residue was proved by microbiological examination. The Hydrolysate produced under the most suitable conditions contained 42% of peptides and proteins. The content of oligopeptides with less than six amino acid residues and oligopeptides with less than three amino acid residues are 12.64% and 7.56% respectively.In the second part of this study, 72 piglets weaned at 21-day old were randomly allocated to 6 treatments. For each treatment, there were 3 replicates and there were 4 piglets fof each replicate. The diets of these treatments had a same nutrient level, but contained 1%PIH, 3%PIH, 5%PIH, 2%spray dried plasma protein (SDPP), 1%PIH-H%SDPP respectively. Neither PIH nor SDPP was supplemented in the control group. The experiment studied when the piglets were 21-day old and finished at 49-day old. The piglets were weighted at 42 and 49-day old and feed intake was recorded. At 42-day old, 2 piglets from each treatment were slaughtered. Blood samples were analyzed for serum biochemical characteristics, number of lymphocytes and OD value of swine fever antibody. Immune organ indexes were calculated from the weight of spleen, lower jaw lymphnodes and inguen lympnnodes. Amylase, lipase and trypsin activities in duodenum chyme were measured. Tissue samples of duodenum jejunum and ileum were used to measured the villi height and crypts depth of small intestine. Cases of diarrhea were recorded during the experiment and diarrhea indexes were calculated.The result indicated that 1. With the exception of chyme amylase activity of pigtets receiving 1%PIH treatment, chyme amylase, lipase and trpsin activities of piglets receiving other treatments were significantly higher than piglets from the control (P<0.05). The highest amylase and trypsin activities were observed in pigets recerving 5%PIH treatment while the highest lipase activities was observed in piglets receiving 3%PIH treatment. There was no significant difference of enzyme activities between the treatment groups(P>0.05). 2. The villi height and VH/CD in the small intestines were higher in5%PIH group than other groups (p<0.05). Pigs fed the PIH or SDPP diets showed lower crypts depth than control group. 3. The immune organs indexes were significantly higher in PIH or SDPP groups than control group (p<0.05). The pigs fed 5%PIH diet had the highest immune organs index. The difference of immune organs indexes among 2%SDPP, 1%SDPP+1%PIH and 3%PIH groups was not significant (p>0.05). 4. Pigs fed 5%PIH and 2%SDPP diets showed higher serum iron and calcium concentrations compared to the control group (p<0.05). The blood urea nitrogen (BUN)concentration was lower in SDPP or PIH groups than control group (p<0.05). The BUN concentration of 5%PIH was the lowest. Pigs fed 5%PIH and 2%SDPP diets had higher immunoglobulin G (IgG) concentrations than control group (p<0.05). 5. Pigs fed experimental diets except fed 1%PIH diet showed more number of lymphocyte than pigs fed control diet (p<0.05). With the increase of of PIH level, the number of lymphocyte increased. 6. The OD value of swine fever antibody was higher in 5%PIH group than control group (p<0.05), but there was no significant difference among pigs fed 2%SDPP, 1%PIH+1%SDPP, 3%PIH diets(p>0.05). 7. Pigs fed SDPP or PIH diets had lower diarrhea indexes compared with pigs fed control diet (p<0.05). And the diarrhea index of 5%PIH group was the lowest. 8. At the 42 and 49-day old, the liveweighe of pigs fed SDPP or PIH diets except 1%PIH were higher than pigs fed control diet (p<0.05). The average daily gain from 21 to 42 day old and from 21 to 49-day old was higher in pigs fed SDPP or PIH diets than pigs fed control diet (p<0.05), with the pigs fed 5%PIH diet having the highest daily gain. Pigs fed 3%PIH or 5%PIH diet showed lower feed/gain ratio from the age of 21 to 42 days and from 21 to 49 days compared with pigs fed control diets. Pigs fed...