1Department of Clinical Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran
2Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
3Department of Clinical Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
4Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
To estimate the prevalence of subacute ruminal acidosis (SARA) in dairy cows, a total of 196 ruminal fluid samples were drawn by rumenocentesis from 10 dairy herds of Khorasan Razavi province, northeast of Iran. Two groups of 12 cows, early lactation and mid-lactation cows were sampled in each dairy herd and ruminal pH was determined immediately using a portable pH-meter. A total of 54 cows (27.6%) were found to be experiencing SARA. No significant differences were found between SARA affected and non-affected cows in ruminal contractions, faecal quality and fat and protein components of milk.