Effects Of Different Concentrations Of Ammonia On Growth Performance And Digestive Function Of Growing Pigs

In order to study the effects of different ammonia concentrations on the feeding performance and digestive function of growing pigs,a single factor design was adopted in this experiment.Thirty-six 50-day-old Duroc × Landrace × Yorkshire growing pigs with good body condition and similar body weight were randomly divided into 4 treatment groups with 3replicates in each group and 3 pigs in each replicate.The pigs were fed at ammonia concentration: Don’t add(group Ⅰ)and 25 mg/m3(group Ⅱ)and 35 mg/m3(group Ⅲ),45mg/m3(group Ⅳ)of environment control metabolic tank(tank space is 4.5 m × 2.65 m × 2.5 m,in addition to the ammonia concentration,the rest of the environmental parameters control the same level),22 days experiment was carried out(including pilot test period,7 days trying period of 15 days).Fecal samples were collected every day during the trial period,and blood samples were collected and slaughtered for analysis once every 5 days.The results showed as follows:(1)Different ammonia concentration had no significant effects on ADG,AFI and F/G of growing pigs(P > 0.05),but the feed return of low ammonia concentration group was higher than that of high ammonia concentration group.(2)Different ammonia concentration had no significant effect on feed nutrient digestibility of growing pigs(P > 0.05),but the effect of feed nutrient digestibility was related to the experiment time.(3)The weight of liver and pancreas and the length of duodenum,jejunum and ileum of growing pigs were not significantly affected by ammonia concentration(P > 0.05),but the plutocrypto ratio of duodenum and jejunum was significantly affected by ammonia concentration in the third stage of the experiment(P < 0.05).group Ⅳ duodenal velvet implicit ratios were significantly lower than group Ⅰ,the group Ⅱand group Ⅲ 26.47%,16.67%,17.65%,group Ⅰ of jejunum velvet than group Ⅲ and Ⅳ is significantly higher than Cain,36.82%,38.18% respectively.The villus height and crypt depth of duodenum and jejunum and the villus height,crypt depth and velocious-crypt ratio of ileum had no significant effects in other trial stages(P > 0.05).(4)Different ammonia concentration had significant effects on trypsin and lipase in jejunum at the third stage of experiment(P <0.05),but had no significant effects on amylase in jejunum at each stage of experiment(P >0.05),and had no significant effects on pepsin,trypsin,amylase and lipase in pancreas,duodenum and ileum(P > 0.05).Group Ⅲ and Ⅳ jejunum trypsin and lipase activity were significantly lower than group Ⅰ 8.90%,9.35% and 2.08%,1.83%;(5)Different ammonia concentrations had significant effects on serum alanine aminotransferase and urea nitrogen in the second stage(P < 0.05),but had no significant effects on R-glutamyltransferase,alkaline phosphatase,total bilirubin,glucose,total cholesterol and triglyceride(P > 0.05).Group Ⅳcereal third transaminase is significantly higher than other three groups respectively 32.37%,24.43%,23.49%;group Ⅳ of urea nitrogen group Ⅰ,Ⅱ is significantly higher than 21.33%and 14.14% respectively.CONCLUSIONS: Ammonia exposure within 15 days had no significant effect on the growth performance of growing pigs,but it could affect intestinal mucosal morphology,digestive enzymes and some serum biochemical indexes.Considering all these,it is recommended to control the ammonia concentration below 25 mg/m3 in growing pig houses.