THE PERFORMANCE OF DAIRY-COWS OFFERED DRINKING-WATER OF LOW OR HIGH SALINITY IN A HOT ARID CLIMATE

Brackish well water (BW) containing 3574 mg total dissolved solids (TD S) per l was compared with desalinated water (FW, 449 mg TDS per l) as a source of drinking water for dairy cows in the hot arid conditions of Kuwait. Friesian-Holstein cows in early lactation were given daily, 12 kg cereal-based concentrate, 12 kg fresh lucerne and 4 kg senescen t date palm leaves for 196 days with the experimental treatments being either BW or FW (four cows per water type). Dry matter and water inta kes were not affected by water type (P > 0.05). Cows offered BW gained slightly more weight (P > 0-05) than cows consuming FW. Although over all milk yield and composition was unaffected by water type, the decli ne in milk yield as the experiment progressed was significantly (P < 0 .05) less for cows offered BW. Cows offered BW tended to have higher c oncentrations of minerals and thyroid hormones in plasma than cows off ered FW. It can be concluded that water containing 3574 mg TDS per l w as an acceptable source of water for dairy cows.