Milk yield of dairy cows given restricted access to water in a Mediterranean-type climate

Abstract

During summer in the Goulburn Valley, two herds of Jersey- Friesian crossbred cows were used to study the effects of restricted access to drinking water. There were three treatments applied to two herds-(1) free access, (2) 20 min. access before each milking, and (3) 20 min. access before the night milking only. One herd was individually penned and had free access to shade while the other was grazed with no access to shade. Both herds were fed irrigated perennial pasture containing 24.5% dry matter. Maximum air temperature averaged 33.7¦C. Over the whole experiment, restricting the access of dairy cows to drinking water did not significantly reduce mean milk yield (mean 12.6 kg/cow day-1) or mean liveweight of cows (mean 41 1 kg) in either herd. However, during the first 4 days of treatment, mean milk yield and mean liveweight were lower (P < 0.05) for cows on a once-a-day access than for those on either free or twice-daily access. In the pen experiment, intake of drinking water averaged 67,45 and 49 l/cow day-1 for treatments 1, 2 and 3, respectively; dry matter intake was unaffected by treatment (mean 15.6 kg/cow day-1). Because of the modifying influence of shade on the environment of the penned cows, there was no significant effects of climate on their water intake. It was concluded that farmers need not supply drinking water to dairy cows in all paddocks.