Abstract
Given the high incidence of calf diarrhea and the limited data on pathogenic and non-infectious factors in a large-scale dairy farm in Wuwei City, this study aims to investigate the pathogens associated with summer calf diarrhea and the non-infectious risk factors in local large-scale dairy farm. It included 664 diarrheic calves (1-60 days of age, from June 2024 to May 2025), detected 5 types of enteric pathogens in 81 fecal samples collected in summer via RT-qPCR, collected data on non-infectious factors, and applied binary logistic regression and ROC analysis. The annual diarrhea incidence was 14.44%, with a peak in summer. Clostridium perfringens (67.90%) and Bovine Rotavirus (48.14%) were the dominant pathogens, and the rate of mixed infections was 48.14%. Risk factors for calf diarrhea included birth in spring or summer, female, Wagyu, younger age, birth weight < 38.5 kg, primiparous dams, serum immunoglobulin level < 8.1 g/L, and dam calving score > 1; longer duration of treatment was associated with a lower recovery rate. This study identifies key pathogens, risk factors, and their thresholds, thereby providing a scientific basis for the control of calf diarrhea in similar regions.