| Elephantopus scaber Linn.is a perennial herb of Chrysanthemum in Compositae.It is widely distributed in Guangdong,Yunnan,and Guangxi in south China.It has been used in Chinese folklores medicine against fever,cough,arthritis,edema,and sores.In recent times,the effects of Chinese herbal medicine as feed additives to improve growth performance and immune function of broiler chickens have been explored.In this study,I use the ordinary powder of E.scaber(OPES)to prepare the ultrafine powder of E.scaber(UPES)and this was tested in broilers as new green herbal feed additive.Several experiments were conducted.(1)Firstly,the samples of the Chinese herbal plant were milled to produce ordinary powder of E.scaber(OPES)by passing through a 60-mesh sieve.Then a portion of OPES was passed through a 300-mesh sieve to obtain the UPES.Both powders were stored at-20?.(2)Several experiments were conducted using fast-growing yellow-feathered broiler chickens in a 63-day study.There were 6 groups.Group 1(Control):chickens were fed the basal diet only.Group 2(Antibiotic):0.1%of bacitracin zinc was added to the basal diet.Group 3:0.8%of ordinary E.scaber powder(OPES)was added to the basal diet.Group 4 to 6:The basal diet was supplemented with UPES at 0.4,0.8 and 1.2%respectively.Samples and data were collected on 28d and 63d.To explore the effects of UPES on the growth performance of broiler,feed intake,daily weight gain and feed-to-weight ratio were monitored.In addition,the slaughter performance of broilers was also determined.(3)The effects of UPES on immune organ index,immunoglobulin,and immune factor and Newcastle disease antibody titer in broilers were measured at the end of the study.The results are summarized below:(1)E.scaber were cut,and ground in a water mill to prepare the OPES.It was then passed through a 60-mesh sieve.Part of the OPES powder was further pulverized using a ultrafine pulverizer followed by passage through a 300-mesh sieve to prepare UPES.Both powders were stored at-20? to ensure that the active ingredients in the E.scaber can fully exert its pharmacological effects.(2)UPES can improve the growth performance and slaughter performance of broilers.The effect of UPES on the feed-to-gain ratio of broilers was significantly different between the treatment groups and the control group(P<0.05).There was no significant difference in daily weight gain between the test groups and the control group(P>0.05)but there was an increasing trend in the daily weight gain between the test groups 4,5 and 6 and the control group(P>0.05).Between days 29 to 63,the feed intake significantly increased(P<0.05)only in groups 4 to 6 and not groups 2 and 3(P>0.05).The feed-to-gain ratio of treatment group 6 was significantly different from the control group(P<0.05).However,adding UPES to the broiler diets resulted in a significant improvement in the dressed carcass weight percentage,half eviscerated yield percentage and breast muscle yield(P<0.05)and 0.8%of the UPES was the best.(3)The effect of UPES on the immune performance of broilers showed that,there was a significant difference in thymus and bursa indices compared with the control group(P<0.05)but not the spleen index(P>0.05).UPES significantly increased the serum IgG,IgM and IgA,and IL-2 and IFN-? levels in broilers(P<0.05).From day 1 to 28,the antibody titers of the treatment groups 4 and 5 were significant higher compared to the control(P<0.05).From day 29 to 63,the antibody titers of groups 2,4,5 and 6 were significantly higher compared with the control group(P<0.05).The 0.8%UPES performed the best,equivalent to the antibiotic group.In summary,UPES can rupture plant cell wall of Chinese herbal medicines to maximally release the active ingredient so that the bioavailability and efficacy could be increased.My study showed that adding 0.8%of UPES can effectively increase the feed intake and daily weight gain of broilers,reduce the feed-to-weight ratio,and can significantly increase the slaughter performance.Thus it reduces production costs and provides maximum economic benefit to the produce.In addition,it can increase the thymus and bursal indices,serum immunoglobulins,IL-2,IFN-?,and significantly increase antibody titers against Newcastle disease.Antibody titer increases disease resistance.The optimum additive amount of UPES was 0.8%,and the broiler performance was equivalent to the antibiotic group.It is a potential substitute to replace antibiotics in broiler production.It will immensely help to reduce the occurrence of microbial resistance and environmental pollution whilst improving broiler growth and financial benefit to broiler farmers. |
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