Abstract

Three small studies were undertaken in the Waikato involving daily measurements of water intake of individual mixed-age Holstein-Friesian and crossbred cows, mid lactation. In Trial 1 at Ruakura, cows were monitored whilst grazing and, in Trials 2 and 3 at DairyNZ, pasture was cut and fed to cows indoors. Mean daily water intakes by Trial were 41.3, 78.2 and 60.1 L/cow, respectively; standard deviations were 4.5, 8.3 and 7.2 L/cow, and between-cow repeatabilities averaged 0.56 ± 0.08. There were two days of rain in Trial 1; the greater of these rainfalls (26.4 mm) led to a 62% reduction in water intake. There was no rainfall above 2 mm in Trials 2 or 3. Daily feed intakes (and feed dry-matter percentages) of cows were also available (Trials 2 and 3), and combined daily water intake (calculated from actual-water intakes plus water content of the feed consumed) averaged 104.5 and 110.6 L/cow, respectively. At an average water intake from the trough of 60 L/cow, the 25% of cows drinking least are expected to drink ~8.4 L (14%) less than average. This knowledge is useful when planning management practices such as supplementing water with zinc sulphate for facial eczema protection.

CA, Morris, SM Hickey, ER Thom, and CD Waugh

Proceedings of the New Zealand Society of Animal Production, Volume 70, Palmerston North, 257-260, 2010