Importance of Water Quality in the Diet of Milch Cows under the Climatic Conditions of Tonk District, Rajasthan (India)

Water quality is a critical yet often overlooked determinant of dairy productivity in semi-arid regions. Tonk district of Rajasthan experiences high summer temperatures, seasonal rainfall, and widespread reliance on groundwater—conditions that can elevate total dissolved solids (TDS), hardness, fluoride, nitrate, and microbial loads in livestock water. This paper examines how water quality interacts with climate, feed intake, and animal health to influence milk yield and composition in milch cows. We outline a field-appropriate study design for Tonk, present illustrative findings based on realistic ranges reported for semi-arid India, and translate evidence into practical recommendations for farmers and local agencies. The synthesis highlights that (i) elevated TDS (>3,000 mg/L), fluoride (>1.5 mg/L), or nitrate (>50 mg/L as NO₃⁻) are associated with reduced water intake, lower dry matter intake (DMI), subclinical health issues, and decreased milk yield and fat%; (ii) microbial contamination significantly increases during the monsoon months; and (iii) low-cost interventions—source selection, trough hygiene, point-of-use disinfection, and defluoridation where indicated—can materially improve productive performance and welfare.