| In recent years,veterinary antibiotic feed additives are frequently used,which lead to abuse of antibiotics and bacterial resistance.With the widespread concern of animal production and food safety,the international community began to realize the harm of antibiotics.EU and some countries have legislated to restrict or even prohibit the addition of antibiotics in feed.The ministry of agriculture and rural affairs of the People’s Republic of China has also issued the policy of substitution,prohibition and cancellation of antibiotics:from January 1,2020,all kinds of feed additives containing growth-promoting drugs(except traditional Chinese medicine)will be withdrawn;from July 1,2020,feed production enterprises will stop producing feed additives containing growth-promoting drugs(except traditional Chinese medicine)for commercial feed.Therefore,the development of Chinese herbal medicine resources and feed application industry is the focus of future research.In this study,yellow-feather broiler was selected as the research object,and the lonicera flos,which has the functions of clearing away heat and detoxification,and evacuating wind heat,was selected as the feed additive to be added to the daily drinking water of broiler.The following experiments were carried out: A total of 150 2-day-old yellow-feather broilers were randomly divided into one control group and four test groups,with 3 replicates of 10 birds.The experiment lasted 52 days,including 1-10 days for environmental adaptation,11-26 days for experiment period I(12-27 days of age),27-42 days for experiment period II(28-43 days of age),43-52 days for experiment period III(44-53 days of age).The broilers in control group were fed with basic diet and drinking water in each experimental period,while in the experiment period I and experiment period II,the broilers in the test group 1,group 2,group 3 and group 4 were fed with basic diet and added 1.0%,1.5%,2.0% and 3.0% of water extract of the lonicera flos(calculated by the mass fraction of the original medicinal materials),the broilers in the test groups were fed with basic diet and drinking water in experiment period III.During the experiment periods,the dead elutriation number of each group was recorded,and at the 27,43 and 53 days of age,respectively,yellow-feather broilers were randomly selected and weighed on an empty stomach,weigh the surplus feed of each group,and calculated the average daily feed intake,average daily gain and feed gain ratio.At the same time,the content of protein(total protein,albumin and globulin),the activity of serum enzyme(alanine aminotransferase,aspartate aminotransferase and γ-glutamyltransferase),the content of other components(total bile acid,creatinine,uric acid,cholesterol,triglyceride and glucose),and the content of Ig G,Ig A and C3 were measured.The spleen,bursa of Fabricius and thymus of broilers were weighed and the index of immune organ was calculated.In addition,at the 43 and 53 days of age,the histological analysis of the liver,kidney and spleen were carried out.The main conclusions are as follows:1.Effects of the lonicera flos feed additive on the growth performance of yellow-feather broiler.Compared with the control group,the survival rate of yellow-feather broiler could be improved by adding the lonicera flos feed additive,and the survival rate of the test group 2 and group 4 was reached 100%.In the experiment period II,the average daily gain of the test group 2 and group 3 compared with the control group were increased 17.25% and 16.56%(P<0.05);the feed gain ratio of the test group 2 compared with the control group was significantly lower(P<0.05).In the experiment period Ⅲ,the average daily feed intake of broiler in the test group 2 was lower than that in the control group(P<0.05);the average daily gain of the test group 4 compared with the control group was significantly reduced 17.22%(P<0.05).The results showed that adding 1.5% and 2% dose of the lonicera flos feed additive could increase the weight,the 1.5% dose of the lonicera flos feed additive could reduce the feed gain ratio,improve the feed efficiency,and achieve the purpose of promoting the growth and improving economic benefits.2.Effects of the lonicera flos feed additive on blood biochemical indexes of yellow-feather broiler.(1)In the experiment period Ⅰ,the total bile acid in the test group 1,group 2 and group 4 was significantly lower than that in the control group(P<0.01);the activity of aspartate aminotransferase in the test group 3 was significantly higher than that in the control group(P<0.05).In the experiment period Ⅱ,the activity of aspartate aminotransferase in the test group 1,group 2 and group 4 was significantly lower than that in the control group(P<0.05).The above results showed that adding 1.0%,1.5% and 3.0% doses of the lonicera flos feed additive could reduce the content of total bile acid in serum and the activity of aspartate aminotransferase.The mechanism of action might be that the lonicera flos as a dual-purpose Chinese herbal medicine,had no toxic side effects on the liver within the limited scope and dosage,and might play a certain role in liver protection.(2)In the experiment period Ⅰ,the content of creatinine in the test group 3 was significantly higher than that in the control group(P<0.05);the content of uric acid in the test group 2 was significantly higher than that in the control group(P<0.05).In the experiment period Ⅱ,the content of uric acid in the test group 1 was significantly higher than that in the control group(P<0.01),and the content of uric acid in the test group 2,group 3 and group 4 was significantly lower than that in the control group(P< 0.01).the glucose content of the test group 1,group 2 and group 3 was significantly rising than that of the control group(P<0.01).The results showed that 1.5%,2% and 3.0% doses of the lonicera flos feed additive could reduce the content of uric acid in serum,maintain the content of creatinine,and have little effect on renal function.It also could increase the serum glucose level in broiler,and improve the metabolism and anti-stress ability.3.Effects of the lonicera flos feed additive on the immune function of yellow-feather broiler.(1)In the experiment period Ⅰ,the bursa of Fabricius of the test groups was extremely significant higher than that of the control group(P<0.01);the spleen index of the test group 1,group 2 and group 3 was significantly higher than that of the control group(P<0.05);the thymus index of the test group 2 was significantly higher than that of the control group(P<0.01).In the experiment period Ⅱ,the bursa of Fabricius of the test group 2 was extremely significant higher than that of the control group(P<0.01),and the bursa of Fabricius of the test group 4 was extremely significant lower than that of the control group(P<0.01);the spleen index of the test group 2 was significantly higher than that of the control group(P<0.05).According to the three immune organ indexes,adding 1.5% dose of the lonicera flos feed additive could improve the immune organ indexes of bursa of Fabricius,spleen and thymus,promote the development of immune organs,thus enhance the body immunity and promote the growth of broilers.(2)In the experiment period Ⅰ,the Ig A of the test group 1 was higher than that of the control group(P<0.05).In the experiment period Ⅱ,the Ig G of the test group 2 was higher than that of the control group,and the difference was extremely significant(P<0.01);the Ig A of the test group 1 and group 2 was higher than that of the control group(P<0.01),and the Ig A of the test group 4 was 27.88% higher than that of the control group(P<0.05).The results showed that the addition of 1% and 1.5% doses of the lonicera flos feed additive could improve the serum Ig A and Ig G,enhance the humoral immune response,and improve the resistance of broilers to external virus and bacterial infection.4.Effects of the lonicera flos feed additive on the organ histomorphology of yellow-feather broiler.At 43 days of age,the damage degree of liver,kidney and spleen of yellow-feather broiler was different with different doses of the lonicera flos feed additive.The damage degree of liver,kidney and spleen of the test group 1 and group 2 was slight,while that of the test group 3 and group 4 was serious.At the 53 days of age,the inflammatory cells in the organs of the test groups were reduced,and the bleeding phenomenon was reduced compared with that at the 43 days of age,especially the inflammatory cells in the liver,the vacuoles in the kidney and spleen,and the bleeding phenomenon were reduced.The results showed that 1.0% and 1.5% doses of the lonicera flos feed additive had little damage to the organs of yellow-feather broiler,and the damage of liver,kidney and spleen recovered after feeding stopped,had no significant effect on the growth of yellow-feather broilers.However,we should pay attention to the dosage added in the actual production and application,so as not to cause organ damage.According to the experimental results of growth performance indexes,blood biochemical indexex,immune function indexex and organ histomorphology,the test group 2(1.5% dose of the lonicera flos feed additive)had the best effects,which could promote the growth and development of yellow-feather broiler,reduce the feed gain ratio and improve the feed efficiency,promote the body’s immune organ development,enhance the humoral immune to improve poultry immunity,and minimum influence on organ organization. |
PDF Full Text Request