Effects Of Macleaya Cordata Extract On Production Performance,Antioxidant Capacity And Intestinal Health Of Commercial Broilers Challenged With Clostridium Perfringens

In order to study the effects of Macleaya cordata extract(MCE)on production performance,antioxidant capacity and intestinal health of commercial broilers challenged with Clostridium perfringens(Cp).720 one-day-old AA broilers were randomly divided into eight treatments with six repeats per treatment and 15 broilers per repeat.2 × 4 factorial design was adopted,that is,four treatments were set up on the basis of Cp challenge and no challenge,and MCE 0 mg/kg,200 mg/kg,400 mg/kg and 800 mg/kg were added,respectively.All commercial broilers were raised in cages and the diet composition and nutrition level were consistent among all treatments.At the age of 21 and 42 days,one animal in each repeat was slaughtered randomly.The meat production performance,serum and liver antioxidant capacity,immune organ index,intestinal development,intestinal lesion score and cecal microflora were measured,and average daily gain,average daily feed intake and other growth performance were calculated.(1)Growth and meat performance: Cp challenge had no significant effect on growth performance at all two stages(P > 0.05);the MCE supplementation significantly reduced the Feed/Gain(F/G)during the early growth stage(1-21 day)(P < 0.01),and the F/G decreased linearly with the increase of MCE supplementation(P < 0.001).Cp challenge and MCE supplementation had no significant effect on meat performance at 21 day(P > 0.05),but Cp challenge negatively affected the eviscerated yield percentage and abdominal fat percentage at 42 day(P < 0.01).There was also a significant linear relationship between half-eviscerated yield percentage and MCE dosage(P < 0.05).Cp challenge and MCE supplementation had no interactive effect on growth and meat performance.These findings suggest that Cp challenge could reduce meat performance,while MCE may improve the growth and meat performance to a certain extent.(2)Immune organ indexes and antioxidant capacity: at 21 day,Cp challenge significantly increased thymus index(P < 0.05),but MCE supplementation had no significant effect on immune organ indexes(P > 0.05).At 42 days,neither Cp challenge nor MCE supplementation significantly affected the immune organ indexes(P > 0.05).Both Cp challenge and MCE supplementation also had no significant effect on the antioxidant capacity of serum and liver at 21 and 42 day(P > 0.05).No interactive effects between Cp challenge and MCE supplementation were detected on the immune organ indexes and antioxidant capacity of serum and liver,except the Bursa index(at 21 day).These results suggest that Cp challenge may stimulate the growth of thymus during the early growth stage(1-21 day),but both Cp challenge and MCE supplementation may have no significant effect on the growth of thymus,spleen and Bursa during the late growth stage,and both Cp challenge and MCE supplementation may also not affect the antioxidant capacity of serum and liver.(3)Intestinal development and intestinal lesion score: both Cp challenge and MCE supplementation had no significant effect on the intestinal development at 21 and 42 day(P >0.05),but the total weight of intestinal tract increased linearly with the increase of MCE dosage at 42 days(P < 0.05).Cp challenge significantly increased the duodenal score at 21day(P < 0.05)as well as the duodenal and jejunal scores at 42 day(P < 0.05).Although MCE supplementation did not affect the intestinal lesion scores significantly,the duodenal and jejunal scores decreased linearly with the increase of MCE dosage at 42 day(P < 0.05).Cp challenge and MCE supplementation had no interactive effect on both intestinal development and intestinal lesion score.In a word,Cp challenge had no significant effect on the intestinal development,but significantly aggravated intestinal injury.MCE supplementation can improve the development and health of the intestinal tract during the late growth stage.(4)Cecal microflora:(1)Both Cp challenge and MCE supplementation had no significant effect on the α diversity of the cecal microflora at both 21 and 42 day.(2)According to the level of phylum,at 21 day,Cp challenge significantly increased the relative abundance of Bacteroideta and Desulfobacterota(P < 0.05),but significantly decreased the relative abundance of Actinobacteria(P < 0.01);MCE supplementation significantly increased the relative abundance of Actinobacteria(P ≤ 0.01),and with the increase of MCE dosage,the relative abundance of Actinobacteria presented a quadratic trend(P < 0.05).At42 day,both Cp challenge and MCE supplementation had no significant effect on the relative abundance of all phyla listed,but the relative abundance of Actinobacteria increased linearly with the increase of MCE dosage(P < 0.05).(3)According to the level of family,at 21 day,both Cp challenge and MCE supplementation significantly decreased the relative abundance of Selenomonadaceae(P ≤ 0.01),and this decline showed a significantly linear or quadratic relationship with the increase of MCE dosage(P < 0.05).The relative abundance of Lachnospiraceae also increased linearly with the increase of MCE dosage(P ≤ 0.01).At 42 day,Cp challenge significantly reduced the relative abundances of Ruminococcacea and Lachnospiraceae(P < 0.05),and at the same time,increased the relative abundances of Prevotellaceae and Lactobacillaceae(P < 0.05);MCE supplementation significantly affected the relative abundance of Barnesiellaceae in a quadratic trend(P < 0.05).Cp challenge and MCE supplementation had no interactive effect on the relative abundances of all phyla and families listed,except the Actinobacteria and Selenomonadaceae(at 21 day).These results suggest that Cp challenge and MCE supplementation could affect the diversity of cecal microflora at least on level of phylum and family.In conclusion,Cp challenge negatively affected the production performance and intestinal health of broilers,but had no significant effect on antioxidant capacity.MCE supplementation could improve the production performance and intestinal health of broilers(especially a significant dose effect on the reduce of the F/G),but also had no significant effect on antioxidant capacity.Cp challenge and MCE supplementation had no interactive effect on all testing indexes,except the Bursa index,as well as the relative abundances of Actinobacteria and Selenomonadaceae(all at 21 day).