Abstract
Measurements were made of intakes of drinking water and food dry matter of 27 lactating Holstein--Friesian cows over a two-year period. Average daily intake (kg/cow) of drinking water and dry matter were 75.4 and 16.9 respectively for animals producing 13.7 kg milk/day in an environment with a mean air temperature and a relative humidity of 26.2 degrees C and 75.7% respectively. Intake of water per kg dry matter consumed after subtracting water in milk was 5.8 kg. Milk yield was positively related to measures of water intake. Concentrate dry matter intakes above 3 and 5 kg depressed forage and total dry matter intakes respectively. It was concluded that under similar conditions supplying of 3 kg/cow/day of concentrate dry matter would maximise forage intake though not necessarily milk production; also the daily drinking water requirements can be estimated from the equation Y (kg drinking water) = 59.2 + 1.18 X (X = kg milk yield) R2 = 0.098.