ABSTRACT
A 1:1 matched case-control study of calves under 1 month of age was carried out by weekly visits to 7 dairy farms in Mashhad, Iran. Fecal samples were collected from 112 calves with diarrhea and 112 controls matched assessed by scoring. Rotavirus and Coronavirus were isolated by antigen capture ELISA test. We found Rotavirus antigen in 29.5% in diarrheic and 17% in normal calves. We detected Coronavirus antigen in 2.7% and 1.8%, respectively. In diarrheic calves Rotavirus was most prevalent at 3rd week age whereas Coronavirus was found in very few cases by 2nd week. Excretion of Rotavirus in feces of scouring calves was greater (P < 0.03) than controls with odds ratio of 1.9 (1.05 - 3.76). We found no relationship between shedding Coronavirus in feces and diarrhea (P value =0.66) with odds ratio equals to 1.4 (0.24 -9.05). We find that Rotavirus is associated with newborn calf diarrhea in industrial dairy farms in Iran.