| Early weaning of young rabbits is crucial for improving production efficiency in largescale farming processes.However,early-weaned rabbits are prone to weaning stress syndrome due to factors such as changes in feed,immature digestive systems,pathogen invasion,and weaning.When young rabbits experience weaning stress,the intestinal environment is vulnerable to pathogenic microorganisms such as Clostridium perfringens,which stimulate the secretion of inflammatory factors and damage the intestinal mucosal barrier function.This leads to decreased feed intake,reduced daily weight gain,decreased immunity,imbalanced intestinal flora,and even death,resulting in significant economic losses in rabbit production.Since the approval of antibiotics as feed additives by the Chinese Ministry of Agriculture in 1994,antibiotics have been widely used in rabbit farming.Although clinical studies have shown that antibiotics can improve the clinical symptoms of weaning stress syndrome in young rabbits,there are also many drawbacks,such as drug residues,bacterial resistance,and antibioticassociated diarrhea.Faced with the irreversible trend of antibiotic restriction or prohibition worldwide,the rabbit farming industry urgently needs safe and effective antibiotic substitutes to control weaning stress syndrome in young rabbits.Traditional Chinese medicine has many advantages,such as a wide range of sources,diverse activities,and no drug residues,making it an important resource for the development of new drugs.In this study,we defined weaning stress syndrome in young rabbits as "liver depression and spleen deficiency syndrome" through the dialectical analysis of the Chinese veterinary community.We selected the classic formula Tongxieyaofang,which is used to treat liver depression and spleen deficiency syndrome,to prevent and control weaning stress syndrome in young rabbits.The primary research content and results are presented as follows:Study on the Preparation Technology of Tongxieyaofang Granules: After analyzing the main components of the prescription medicine,paeoniflorin and hesperidin were selected as evaluation indexes.A single-factor experiment was designed based on the material-liquid ratio,extraction time,and extraction times.Based on the results of the single-factor experiment,the optimal water extraction process was further determined using the orthogonal design method.The results showed that the optimal extraction process for Tongxieyaofang Granules was a material-liquid ratio of 1:25,reflux extraction 2 times,each time for 150 minutes.The extracted liquid was then filtered,and the filtrate was concentrated by vacuum concentration to a liquid extract(the mass ratio of the raw material to the extract was 2:3),dried in a vacuum drying oven(60℃,0.09 Mpa),and then crushed and sieved to obtain the extract powder.The wet granulation process was optimized using the star point-response surface method,and the optimal formulation was determined as follows: the ratio of excipients(extract powder:excipient)was 1:1.5,and the proportion of excipients(soluble starch: pregelatinized starch)was 3.24:1,with an ethanol volume fraction of 63%.Research on quality standards of Tongxieyaofang Granules: The qualitative identification of the four medicinal materials(Atractylodes macrocephala,Paeonia lactiflora,Citrus reticulata,and Saposhnikovia divaricata)in Tongxieyaofang was carried out using thin-layer chromatography.The results showed clear spots and good separation of the four medicinal materials.According to the relevant regulations of the "Chinese Veterinary Pharmacopoeia" for Granules,measurements of particle size,moisture content,and dissolution were conducted,and the results were in compliance with the regulations.The contents of paeoniflorin,hesperidin,and Prim-O-glucosylcimifugin in the Granules were determined by high-performance liquid chromatography,and methodological investigations were also conducted.The results showed that the contents of paeoniflorin,hesperidin,and Prim-O-glucosylcimifugin met the requirements,and the methodological investigations were satisfactory.Content determination,accelerated testing,and long-term stability testing were carried out on three batches of Granules samples,and the results showed that the quality of the Granules remained stable during the testing period.The present study aimed to investigate the protective effect of the Chinese herbal medicine formula Tongxieyaofang Granules on intestinal barrier function in weaned rabbits.A total of 60 weaned rabbits of both sexes aged 35 days were randomly divided into four groups: control,low-dose,medium-dose,and high-dose,with 15 rabbits in each group.The rabbits were administered the corresponding dose of Tongxieyaofang Granules for 10 consecutive days.The initial and final body weights of the rabbits were recorded,and blood,jejunum,colon,and cecum contents were collected for measurement of digestive enzyme activities,intestinal barrier protein levels,inflammatory cytokine levels,and cecal microbiota abundance.The results demonstrated that Tongxieyaofang Granules increased villus height/crypt depth,enhanced intestinal digestive enzyme activities,promoted the generation of tight junction proteins in the jejunum and colon,reduced inflammation,and improved the abundance of intestinal microbiota.In summary,this study conducted a comprehensive and systematic investigation on the Tongxieyaofang Granules from various aspects including extraction process,preparation process,content determination,method validation,quality standards,and prevention and control of weaned rabbit stress syndrome.The results showed that the prepared Tongxieyaofang Granules have strong stability,high content of effective components such as paeoniflorin,and ideal prevention and control effect on weaned rabbit stress syndrome.This study also demonstrated that Tongxieyaofang Granules can effectively improve the growth performance of weaned rabbits,protect the intestinal mucosal barrier,and provide a candidate Chinese medicine preparation for the prevention and control of weaned rabbit stress syndrome. |
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