Effects Of Artemisia Annul L.Water Extract On Growth Performance And Intestinal Related Indexes In Broilers

The purpose of this experiment was to study the effects of different doses of Artemisia annul L.water extract(AAWE)on growth performance,nutrient apparent metabolism rate,intestinal enzyme activity,intestinal morphology,intestinal microorganisms and fecal harmful gas emission of broilers.In the experiment,2401-day-old Arbor Acres(AA)broilers were randomly divided into 6 dietary treatment groups,five replicates for each treatment,eight chickens for each replicate,half male and half female.The control group was fed the basal diet,and the additive groups were fed the basal diet added with 500,1000,1500 and 2000 mg/kg AAWE and 50 mg/kg of chlorotetracycline(CTC),respectively.The experiment was conducted for 42 days,which was divided into the earlier stage(1-21d)and the later stage(22-42d).Feed and drinking water were freely available during the trial.The results were shown as follows:1.According to the regression statistics,with the increase of AAWE dosage,average daily feed intake(ADFI)of broilers showed a linear decrease(P<0.01),average daily gain(ADG)and the ratio of feed to gain(F/G)showed a quadratic increase(P<0.01);the apparent metabolic rate of dry matter in broilers showed a trend of linear increase(P=0.08),and that of crude protein showed a linear increase(P<0.01)in the earlier stage.In the later stage,the apparent metabolic rates of dry matter,crude protein and crude fat in broilers showed a quadratic increase(P=0.05,P<0.01,P=0.03).The ADFI in the whole period showed a linear decrease(P=0.03).According to the results of variance analysis,in the earlier stage,ADFI of 2000 mg/kg AAWE treatment group was significantly lower than that in the control group,CTC group and the 1500 mg/kg AAWE group(P=0.01),and ADG of 2000 mg/kg AAWE treatment group was significantly lower than that in other experimental groups(P<0.01),F/G of 2000 mg/kg AAWE treatment group was also significantly higher than that of other treatment groups(P<0.01);the crude protein apparent metabolic rate in 1000 and 2000 mg/kg AAWE groups was significantly higher than that in the control group and 500 mg/kg AAWE treatment group(P=0.02).In the later stage,the apparent metabolic rate of crude protein in 500 and 1000 mg/kg AAWE groups and CTC group was significantly higher than that in the control group(P<0.01);the apparent metabolic rate of crude protein in 1000 mg/kg AAWE group was significantly higher than that in 2000 mg/kg AAWE group(P<0.01);the apparent metabolic rate of crude protein in CTC group was significantly higher than that in 1500 and 2000mg/kg AAWE treatment group(P<0.01).2.According to the regression statistics,with the increase of AAWE addition level,the crypt depth of duodenum and jejunum of broilers in the earlier stage showed quadratic decline(P<0.01,P=0.01);and the crypt depth of ileum showed a linear decline(P=0.04).In the later stage,the activity of duodenal chymotrypsin and trypsin increased linearly in broilers(P=0.04,P<0.01);the activity of jejunal lipase in broilers increased linearly(P=0.02);and the activity of ileal chymotrypsin also increased linearly(P=0.03);the crypt depth of duodenum and ileum in broilers decreased linearly or quadratically(P<0.01),the crypt depth of jejunum n broilers decreased linearly(P<0.05).According to the results of variance analysis,in the early stage,the duodenal crypt depth of broilers in AAWE addition groups was significantly lower than that in the control group and the CTC group(P<0.01);the jejunal crypt depth of broilers in the AAWE groups and the CTC group was significantly lower than that in the control group(P=0.03).In the later stage of the experiment,the activity of duodenal trypsin in 1500 and 2000 mg/kg AAWE groups was significantly higher than that in the control group,500 mg/kg AAWE treatment group and CTC group(P=0.04);the crypt depth of duodenum in 1000 and 2000 mg/kg AAWE groups and CTC group was significantly lower than that in the control group(P<0.01),and the crypt depth of duodenum in 1500 mg/kg AAWE group was significantly lower than that in the control group and 500 and 1000 mg/kg AAWE groups(P<0.01);the ileal crypt depth of broilers in AAWE treatment group and CTC group was significantly lower than that in the control group(P<0.01);the ratio of villus height to crypt depth in ileum of broilers in 500 and 2000 mg/kg AAWE groups was significantly higher than that in the control group and 1500 mg/kg AAWE group(P=0.02).3.According to the regression statistical results,with the increase of AAWE addition level,the amount of total anaerobe in cecal contents of chickens in the early stage presented a quadratic increase(P=0.04),and the number of Escherichia coli presented a quadratic decrease(P<0.01);the fecal H2S emission decreased linearly(P=0.02)in the earlier stage.In the later stage,the number of total aerobe and Escherichia coli in cecal contents of broilers showed quadratic reduction(P=0.05,P=0.03),and the number of Lactobacillus showed a linear increase(P=0.02).The fecal NH3 emission(24h)reduced quadratically(P<0.01).According to the results of analysis of variance,in the early stage of the experiment,the amount of Escherichia coli in caecum of AAWE group and CTC group was significantly lower than that in the control group(P--0.05);the fecal NH3 mission(72h)in CTC group was significantly lower than that in the control group and 2000 mg/kg AAWE group(P=0.05);the emission of NH3(72h)in 1000 mg/kg AAWE group was significantly lower than that in the control group(P=0.05);the fecal H2S emission in 1500 mg/kg AAWE group was significantly lower than that in the control group,500 and 1000 mg/kg AAWE groups and CTC group(P=0.02).In the later stage of the experiment,the emission of NH3(24h)in the AAWE groups and CTC group was significantly lower than that in the control group(P=0.03).To sum up,adding AAWE in diet could regulate intestinal microecological structure,improve the intestinal digestive enzyme activity and mucosal morphology,enhance the capacity of small intestine to absorb nutrients,improve the utilization rate of nutrients,promote the growth of broiler chickens in the earlier stage,and reduce effectively the emissions of harmful gas in feces,and have the potential to replace antibiotics in feed.