Effect Of Sodium Butyrate On Growth Performance, Immune And Intestinal Function In Weaning Pigs

This research was conducted to determine the effect of adding Zn-Gly on growth performance immunity and intestinal function of weanling piglets and approach to the mechanism.A total of one hundred and sixty two healthy weanling crossed (Duroc×Landrace×Yorkshire) pigs, aged 28 days with the body weight of about 8 kg were randomly divided into 6 groups, each with 3 replicates of 9 pigs. The treatments were as follows:1) control:no antibiotics and sodium butyrate supplementation,2) antibiotics group:0.01% dietary chlortetracycline,3) 0.1% dietary sodium butyrate,4) 0.1% dietary sodium butyrate+0.01% chlortetracycline,5) 0.3% zinc oxide+0.01% chlortetracycline,6) 0.1% dietary sodium butyrate+0.01% chlortetracycline+0.3% zinc oxide. During the last week of experiment 0.5% Cr2O3 was added to the diet for digestibility measurements. After 21 d feeding trial, three piglets were selected from each group which weighed approximately to be slaughtered at the local abattoir and samples (including serum, pancreas, spleen, lymphonodi mesenterici, intestine and duodenum contents) were collected for analysis.The main results were as follows:1. Growth performanceThe inclusion of sodium butyrate in the diet failed to influence the final weight, ADG and F/G in pigs in comparison with the control diet. On the other hand, a significant increase of sodium butyrate combining chlortetracycline or zinc oxide in the final weight and ADG were recorded. In comparison with the experimental groups, a significant increase in the incidence of diarrhea was observed in the control group, and the pigs fed sodium butyrate with chlortetracycline had the lowest diarrhea incidence. There was a trend for a numerical decrease in F/G for pigs fed chlortetracycline with sodium butyrate (P=0.097). 2. Immune functionsThe pigs fed zinc oxide or sodium butyrate had a greater immune organs index. Compared with the control, the spleen index of zinc oxide+sodium butyrate group increased by 50.85%(P<0.05); the pancreas index of chloroteracycline+sodium butyrate group increased by 47.54%(P<0.05); the lymphonodi mesenterici index of zinc oxide group increased by 18.75%(P<0.05).Sodium butyrate added to the diet of pigs at the level of 300 mg/kg sig(?)f(?)cantl y elevated serum IgG level during the period from 0 to 21 days compared to the control (P<0.05). Sodium butyrate supplementation had no effects on IgA, IgM, C3 and C4 in serum during the period from 0 to 21 days (P<0.05). Compared with the control, the IgM level of zinc oxide group increased by 48.48%(P<0.05).Sodium butyrate combining chlortetracycline increased (P<0.05) the contents of C3 and IgG in serum.Compared to the control, adding 0.1% sodium butyrate or 0.3% zinc oxide to the diet can evidently increase the contents of IgA in intestinal mucosa to weaning pigs. Pigs fed 0.01% chloroteracycline+0.1% sodium butyrate had the highest IgA contents in intestinal mucosa.3. Hematological characteristicsSodium butyrate increased (P<0.05) serum glucose. However the difference between sodium butyrate group and sodium butyrate+chlortetracycline group was not significant. Supplementations with sodium butyrate+zinc oxide or sodium butyrate or chlortetracycline increased the level of free fatty acid in serum. Triglycerides of pigs fed sodium butyrate combining chlortetracycline were significantly increased when compared with the control (P<0.05). Dietary sodium butyrate declined the concentration of SUN greatly (P<0.05). Serum D-lactic acid was greatly reduced in all experimental groups. A similar decline in serum DAO occurred between experimental groups and control group. Compared with the control group, D-lactic acid and DAO of piglets in sodium butyrate+chlortetracycline group dropped by 44.36% and 46.22%, respectively.Feeding diets containing sodium butyrate or chlortetracycline decreased the level of serum cortisol (P<0.05). The cortisol concentration in sodium butyrate+ chlortetracycline group, zinc oxide group and sodium butyrate+zinc oxide group droped by 43.13%,43.14% and 47.01% than that of controls. Insulin was higher in sodium butyrate+chlortetracycline group and sodium butyrate+zinc oxide group than in control group (P<0.05). Feeding diets containing sodium butyrate or chlortetracycline did not alter serum glucagon compared with pigs fed the control diet.4. Intestinal functionThe results of vitro digestion showed that the total tract apparent digestibility of crude protein and crude fat were significant improved by 10.13%(P<0.05) and 8.43% (P<0.05) in sodium butyrate containing diet as compared to the basal diet. The study of endogenous digestive enzyme indicated that the activities of trypsin, distase and lipase in duodenum contents were improved (P<0.05). The activities of trypsin were decresed obviously in sodium butyrate group than in sodium butyrate+ chlortetracycline group. Compared with chlortetracycline, supplementation of sodium butyrate or zinc oxide ehhanced the activity of diastase. The activity of lipase in pigs fed sodium butyrate+chlortetracycline was higest. However the difference between sodium butyrate+chlortetracycline group and sodium butyrate+zinc oxide group was not significant.The PH value of duodenum, jejunum and ileal declined when adding sodium butyrate, but there were no significant difference among all the groups.Piglets with basal diet had trend of villus atrophy, crypt depth and mucosal thinning. There was pronounced different of villus height and crypt depth compared to piglets with sodium butyrate and the control at day 21. Diet supplementation with sodium butyrate and zinc oxide decreased these damages.Bacillus acidi lactici of pigs in sodium butyrate group was higher than control groups (P<0.05). The addition of supplementation sodium butyrate resulted in the decrease of E coli (P<0.05).