Efficacy Of Natamycin As A Fungicide On Feed Preservation And Chicken Performance

In recent years,contamination of feed mold is very common during production,processing,and storage,which has become a worldwide problem in poultry and livestock production and feed industry.It has caused a huge economic loss.The aim of this study was to investigate the effects of natamycin,as a feed preservative,on mold prevention and provide reference frame of the proper dosage used in poultry production.1.Effects of natamycin on feed appearance and mildew count during storage.The aim of this study was to explore the preservative effect of natamycin in feed by using mould count method.Feeds were prepared and divided into seven groups with six replicates.Each replicate had two parallel samples.The control group was not added mildew preventive and the other groups were supplemented with 500 mg/kg calcium propionate(CA),2.5,5,10,20 or 30 mg/kg natamycin(NT),respectively.The results showed as follows:(1)Feed appearance in strengthening feed mildew test showed that feeds supplementation of 2.5-20 mg/kg NT could alleviate the mildew during the period of storage.Feed appearance in the regular feed mildew test showed that feeds supplementation of 5-30 mg/kg NT could alleviate the process of feed mildew and extend the feed storage period.(2)In strengthening feed mildew test,compared with the control group,feeds supplementation of NT significantly decreased feed mold count(P<0.05)at 5 d and 10 d.At 15 d,feeds supplemented with 2.5,5 or 10 mg/kg NT significantly decreased mold content(P<0.05)as compared with the control group.At 20 d,feed supplementation of 5 mg/kg NT significantly decreased mildew content(P<0.05)as compared with the control and CA groups.In the regular feed mildew test,compared with the control group,feeds supplemented with 10,20 or 30 mg/kg NT significantly reduced feed mold count(P<0.05)at 30 d.At 45 d,feeds supplemented with 20 and 30 mg/kg NT significantly decreased feed mold count(P<0.05)as compared with the control group.2.Effects of natamycin on feed proximate nutrients during storage.Feeds were prepared and divided into seven groups with six replicates.Each replicate had two parallel samples.The control group was not added mildew preventive and the other groups were supplemented with 500 mg/kg CA,2.5,5,10,20 or 30 mg/kg NT,respectively.The results showed as follows:(1)In strengthening feed mildew test,ether extract content of feed supplemented with 10 mg/kg NT was significantly higher than the control group(P<0.05)at 5 d,15 d and 20 d during the period of storage.(2)In the regular feed mildew test,at 45 d,the moisture content of feed supplemented with 20 mg/kg NT significantly decreased(P<0.05)as compared with the control group.Ether extract content of feed supplemented with 10 mg/kg NT was higher than the other groups(P<0.05)at 45 d.At 60 d,ether extract content of feeds supplemented with 5 and 10 mg/kg NT was significantly higher than the control group(P<0.05).3.Effects of natamycin on growth performance and organs of broilers.A total of 480 broilers were fed with basal diets(CON group),basal diets supplemented with 10,50 or 100 mg/kg natamycin(T1,T2 or T3 group)for 42 d,respectively.The results showed as followed:(1)In the present study,there was no significant difference(P>0.05)in growth performance of broilers.(2)The high level of natamycin(100 mg/kg)for a long period of feeding may have risk of damaging liver function and intestinal villus of the duodenum and ileum in broilers.4.Effects of natamycin on serum biochemical parameters and antioxidant capacity of broilers.A total of 480 broilers were fed with basal diets(CON group),basal diets supplemented with 10,50 or 100 mg/kg natamycin(T1,T2 or T3 group)for 42 d,respectively.The results showed as follows:(1)Serum WBC,RBC and HGB in T2 and T3 groups were significantly increased(P<0.05)as compared with the CON group at 42 d.WBC and RBC in T2 group were higher(P<0.05)than T1 group at 42 d.WBC,RBC,HGB and HCT in T3 group were higher(P<0.05)than T2 group at 42 d.(2)Serum urea nitrogen and alanine aminotransferase were significantly increased(P<0.05)in T2 and T3 groups,while alkaline phosphatase in T3 group significantly decreased(P<0.05)compared to the CON group at 42 d.Serum globulin content was lower(P<0.05)in T2 group at 21 d and T3 group at 42 d than that of the CON group.Serum total protein content in T2 and T3 groups were lower(P<0.05)than that of the CON group at 42 d.(3)Serum total antioxidant capacity was higher(P<0.05)and malondialdehyde content was lower(P<0.05)in T1 group than that of the CON group at 21 d.(4)Serum glutathione peroxidase enzyme activity was significantly increased(P<0.05)and malondialdehyde content was significantly decreased(P<0.05)in T1 group compared to the CON group at 42 d.Malondialdehyde content of liver in T1 group was lower(P<0.05)than that of the CON group.(5)The mRNA expression of Cu/ZnSOD and GPxl in T3 group were significantly decreased(P<0.05)compared with that of T1 group.Conclusions:(1)In the present study,the dosage of 10-20 mg/kg natamycin could alleviate the process of feed mildew,protect the nutritional value of feed,and extend the feed storage period.(2)Diets supplemented with natamycin has no influence on growth performance in broiler chickens.Supplementation of 10 mg/kg natamycin in poultry may have positive influence on liver protection and antioxidant enzyme activities,while 100 mg/kg natamycin may have risk of damaging liver functions in broilers.More investigations with regard to the usage of natamycin in broilers should be carried out.