Abstract
Nine milch cows of Tharparkar and Sahiwal breeds, selected a fortnight after calving, were divided into three groups of three cows each for trials during the winter and summer seasons. Nine different rations were fed, having various combinations of digestible crude protein and total digestible nutrients contents of 125, 100 and 75 per cent of the mean value of the upper and lower limits of Morrison's standard. Significantly (P < 0·01) more metabolic water was produced during the winter which may account for the lower water requirement of cows in this season. The findings of the study confirmed that the values of insensible water to, total water input and water input per kilogramme dry matter intake were significantly (P<0.0l) more during the summer.