WATER DRINKING BEHAVIOUR OF STEERS FED EITHER FRESH CUT FORAGE OR FIRST CUT HAY

To study the effect of moisture content of the diet on drinking behaviour and the amount of water drunk, observations were made on 8 Holstein steers fed either fresh cut forage or first cut hay. The observations were made in a barn with a mean temperature of about $13^{\circ}C$. Drinking occurred mainly within 3 hours after feeding for the steers fed hay, while those fed soilage drank casually. Frequency of drinking (F) was related to the dry-matter concentration (DMC, %) of herbage: F = 0.47 (${\pm}0.09$) DMC - 6.5, $SE={\pm}0.4$, r = 0.86, P<0.01. Intake of drinking water for each 100 kg of live weight (IDW/100kg) for steers fed soilage was related to the dry-matter concentration: IDW/100kg = 0.55 (${\pm}0.06$) DMC - 8.7, $SE={\pm}0.3$, r = 0.94, P<0.01. The intake of water in each drinking period for animals fed fresh forage was curvilinearly related to the drinking frequency; for the hay-fed steers there was a negative linear relationship. When the drinking frequency for steers fed the fresh forage increased to the same as that observed for the hay, water intake in each drinking period was the same as found for the hay-fed steers.