| Abstract | Twenty Boer (6.1 mo and 21.3 kg) and 20 Spanish goat wethers (6.6 mo and 19.7 kg) were used to determine effects of brackish water on feed intake, digestion, heat energy, and blood constituents. Brackish water had 6,900 mg/L total dissolved salts, 1,885 mg/L Na, 75 mg/L Mg, 1,854 mg/L chloride, 2,478 mg/L sulfate, and 9 mg/L boron. Brackish water levels were 0% (control), 33% (33-BR), 67% (67-BR), and 100% (100-BR). Water and a moderate quality grass hay (8.5% CP and 68% NDF) were offered free-choice. The experiment consisted of 14 d of adaptation, 5 d for metabolizability measures, and 2 d for determining gas exchange and heat energy. There were no interactions (P > 0.05) between breed and water treatment. Water (931, 942, 949, and 886 g/d; SE = 59.1) and DM intakes (525, 556, 571, and 527 g/d for control, 33-BR, 67-BR, and 100-BR, respectively; SE = 31.0) were similar among treatments (P = 0.876 and 0.667, respectively). Urinary water was greater for brackish water treatments than for control (P = 0.003; 211, 317, 319, and 285 g/d; SE = 25.6) and fecal water content was similar among treatments (P = 0.530; 247, 251, 276, and 257 g/d for control, 33-BR, 67-BR, and 100-BR, respectively; SE = 19.0), implying less water loss by other means such as evaporation when brackish water was consumed. Total tract OM digestibility was lower (P = 0.049) for treatments with than without brackish water (64.2, 61.5, 58.6, and 59.3%; SE = 1.86), although ME intake was similar among treatments (P = 0.940; 4.61, 4.57, 4.60, and 4.31 MJ/d for control, 33-BR, 67-BR, and 100-BR, respectively; SE = 0.394). Daily heat energy in kJ/kg BW0.75 was less with than without brackish water (P = 0.001; 474, 436, 446, and 445; SE = 7.7), although values in MJ were similar among treatments (P = 0.588; 4.36, 4.12, 4.22, and 4.18 for control, 33-BR, 67-BR, and 100-BR, respectively; SE = 0.124). Body weight of wethers consuming brackish water decreased less than that of wethers consuming control water (P = 0.006; -37, -14, -7, and -16 g; SE = 7.2), but recovered energy was similar among treatments (P = 0.923; 0.25, 0.45, 0.38, and 0.13 MJ/d for control, 33-BR, 67-BR, and 100-BR, respectively; SE = 0.356). In conclusion, brackish water inclusion in drinking water had a number of effects, but it does not appear that consumption of this source would adversely impact performance of growing meat goats. |
