| Since the 1950s,adding low dose antibiotics in feed has been widely used to promote the growth of livestock and poultry,which has brought huge economic benefits to the livestock and poultry industry.However,the use of antibiotics in feeding can cause safety problems such as drug-resistant bacteria and drug residues,which seriously threaten the public health of human beings.The European Union and the United States banned the use of feedstock antibiotics in 2006 and 2017 respectively,followed by China’s announcement of a total ban from 2020,marking a "post-antibiotic era" for the world.Therefore,it is more important and urgent to develop green and safe natural feeding substitutes.Because of its green,safe and effective characteristics,fermenting veterinary drugs have become the focus of public attention and become more and more popular in the market.It is expected that the development prospect of the industry will show a rapid rise in the future.Methods: To improve the efficacy of veterinary medicine,5 probiotics were selected in this study to conduct fermentation treatment on veterinary medicine compound Healthy Chicken Powder composed of 8 Traditional Chinese medicines.Due to the complexity of chemical components in Healthy Chicken Powder difficult to identify,it is not possible to determine the efficacy of chemical composition by the content of a certain level.Therefore,this study selected 252 white fowl,random is divided into 7 groups(blank group,the healthy chickens and 5 strains of fermentation group),the Healthy Chicken Powder and fermented healthy chicken group per kilogram of feed add 20 g Healthy Chicken Powder,chicken powder or fermentation added 42 days continuously,to determine the performance of growth,screening the growth strains with good effect,and the growth performance better group to collect the intestinal contents,on the 16 Sr DNA sequencing,attempts to explore the Healthy Chicken Powder fermentation effect on white chicken gut microbes.At the same time,gradient fermentation time,fermentation temperature,inoculation amount and water content were set for the selected strain,then gradient fermentation was carried out for Healthy Chicken Powder again,and the peak area changes in HPLC analysis of extracts under different fermentation conditions were investigated to try to find out the optimal fermentation conditions for the strain.Experimental results: 1.Two strains with good growth-promoting effect were screened out from the five candidate strains,which were Zygosaccharomyces rouxii with the highest feed utilization rate and Bacillus subtilis with the highest body weight gain rate.2.The 16 S r DNA sequencing of intestinal flora in different experimental groups indicated that the main role of fermented Healthy Chicken Powder may be in the anterior intestine.3.The Lutheran conjugated yeast group was the group with the best production performance among all groups.The increase of Bifidobacteriaceae in the foregut may be an important reason why the fermentation of Healthy Chicken Powder by Zygosaccharomyces rouxii can improve the growth performance of broilers.4.HPLC analysis of the extracts of Healthy Chicken Powder before and after fermentation showed that fermentation temperature,fermentation time,strain inoculation amount,water content and other factors all affected the microbial fermentation efficiency.The ideal fermentation conditions were 26℃,70% water content,2d fermentation and 8% inoculation.The ideal fermentation conditions for Bacillus subtilis were 30℃,70% water content,2d fermentation and 4% inoculum.Experimental conclusion: This study preliminarily revealed the growth-promoting effect of Healthy Chicken Powder on white feather broiler chickens and the regulation difference of intestinal flora between Healthy Chicken Powder and the fermented products of different strains,suggesting that the fermented Healthy Chicken Powder has great potential in the field of resistance,and laid a foundation for the development of other fermented veterinary drugs. |
PDF Full Text Request