Main Article Content
The study aimed to investigate the effects of slightly saline (3000 ppm NaCl), moderately saline water (6000 and 9000 ppm NaCl), and highly saline water (12000 and 15000 ppm NaCl) on growing bovine native heifers during hot summer season of Egypt. Total and daily gain in heifers drank slightly saline water was significantly higher than those in heifers drank River Nile water (RNW). The gain of heifers drank moderately or highly saline water decreased significantly when compared with the gain of heifers drank RNW only. Total water intake (TWI) of heifers in heifers drank slightly or moderately saline water increased significantly, while TWI of heifers drank highly saline water decreased significantly when compared with the WI of heifers drank RNW. Dry matter intake (DMI) increased significantly in heifers drank slightly saline water, while DMI of heifers drank moderately or highly saline water decreased significantly when compared with DMI of heifers drank RNW. Drinking water containing high levels of salts was accompanied by progressively significant increases in urea-N, creatinine, glucose, and cortisol concentrations. Total cholesterol and triglycerides, aldosterone concentrations as well as liver enzymes (alanine transaminase and aspartate transaminase) activities increased significantly while thyroid hormones (T4 and T3) and 17β-estradiol levels decreased significantly in heifers drinking saline water containing RNW diluted with 9000, 12000, and 15000 ppm NaCl. It can be concluded that growing heifers tolerate up to 0.6% NaCl and no advice to use highly saline water (9000, 12000, and 15000 ppm NaCl) in drinking growing heifers, especially, in hot summer season of Egypt.