Evaluation of Ruminal Fluid Characteristics in Ruminal Acidosis of Cattle: A Practical Diagnostic Tool

Abstract

Acid indigestion represents a significant source of economic loss in ruminant production systems due to its detrimental effects on rumen fermentation efficiency and nutrient utilisation. Disruption of normal ruminal function leads to reduced dry matter intake, impaired feed conversion efficiency, and a consequent decline in growth performance or milk yield. In addition to these primary effects, affected animals frequently develop secondary complications, including laminitis, hepatic abscessation, and immunosuppression. These associated conditions further exacerbate production inefficiencies by increasing veterinary intervention costs and contributing to cumulative productivity losses within affected herds. This study aimed to investigate the alterations in physico-chemical and microbiological parameters of ruminal fluid in crossbred Jersey cows diagnosed with acid indigestion. Twelve crossbred Jersey cows presented to the Veterinary Clinical Complex, VC&RI, Theni, were selected and allocated into two groups: clinically healthy controls (Group I, n=6) and cattle with a history of excessive intake of fermentable carbohydrate-rich feed (Group II, n=6). The study was conducted at VC&RI, Theni between January and June 2025. Rumen fluid samples were analyzed for pH, colour, odour, consistency, protozoal motility, ammonia concentration and total volatile fatty acid (TVFA) content. Cattle in Group II exhibited significantly lower ruminal pH (5.33 ± 0.21), reduced ammonia nitrogen levels (14.26 ± 1.75 mg/100 mL) and diminished protozoal motility, alongside a marked increase in TVFA concentration (93.50 ± 5.75 mmol/L) compared to healthy controls. Physical characteristics also differed notably, with acidotic samples showing milky grey coloration, rancid odour, and watery in consistency. These findings highlight that the rumen fluid evaluation can be used as a practical diagnostic test for the identification of metabolic disturbances associated with acid indigestion in ruminants.