甘肃某规模化奶牛场群发性犊牛腹泻案例分析OA

To identify the etiological factors of calf diarrhea in a large-scale dairy farm in Lanzhou,Gansu Province,and provide a feasible anti-resistance prevention and control scheme,this study collected fecal samples from 19 diarrheic calves.Pathogen detection was conducted using colloidal gold technology,RT-qPCR,and saturated salt water flotation method.Drinking water samples were tested for pH,total bacterial colony count,and bacterial isolation and identification.Feed samples were analyzed for toxins via ELISA.The results showed that the nucleic acid positive rate of Clostridium perfringens(Cp)was 52.63%(10/19),and that of Cryptosporidium(COWP)was 5.26%(1/19).No other pathogens such as Bovine Rotavirus(BRV),Bovine Coronavirus(BCoV),or Bovine Viral Diarrhea Virus(BVDV)were detected.The drinking water was slightly alkaline(pH 8.73±0.14)with an excessive total bacterial colony count of 3.35×103 CFU/mL,from which Bacillus pumilus(BP)was isolated.Mycotoxins such as vomitoxin and zearalenone in feed were negative.On-site investigation revealed environmental and management issues including mixed feeding of diarrheic and healthy cattle,accumulated water and feces in pens,poor ventilation,and overuse of antibiotics.The outbreak was confirmed to be mainly caused by Cp infection,accompanied by drinking water contamination and improper environmental management.A comprehensive prevention and treatment scheme combining traditional Chinese and Western medicine was formulated.After one month,the total diarrhea incidence of the herd decreased from the initial 6.63%to 2.11%.This study clarified the etiological factors of diarrhea in the farm,verified the effectiveness of the anti-resistance and antibiotic-substituting prevention and control scheme,and provided practical references for diarrhea prevention and control in large-scale dairy farms in Gansu region.