PSVI-11 - Effects of Levels of Minerals of a Natural Source of Brackish Water and Nacl on Digestion and Ruminal Methane Emission by Different Breeds of Goats and Hair Sheep

Abstract: Angora, Boer, and Spanish doelings and Dorper, Katahdin, and St. Croix ewe lambs (six per type; initial age=9.7±0.07 mo) consumed water varying in mineral levels of a natural brackish source (BR) and NaCl (SL) to determine effects on digestion and ruminal methane emission. There were six simultaneous 6×6 Latin squares with 3-wk periods, analyzed by a mixed effects model and repeated measure of period. Water treatments (WT) were fresh (FR), BR alone (100-BR), similar total dissolved salt (TDS) level as 100-BR via NaCl addition to FR (100-SL), BR with concentrations of all minerals increased by approximately 50% (150-BR), similar TDS level as 150-BR by NaCl addition to FR (150-SL), and similar 150 TDS level by adding a 1:1 mixture of BR minerals and NaCl to 100-BR (150-BR/SL). Concentrations (mg/kg) in BR were 4,928 TDS, 85.9 bicarbonate, 225 calcium, 1,175 chloride, 60.5 magnesium, 4.59 potassium, 1,387 sodium, and 1,962 sulfate, and TDS was 453, 5,684, 7,508, 8,222, and 7,319 for FR, 100-SL, 150-BR, 150-SL, and 150-BR/SL, respectively. Wheat hay (10.0% crude protein and 66.8% neutral detergent fiber) was consumed ad libitum. There were no effects of WT or AT×WT interactions for these variables. Dry matter intake in wk 3 was least among AT (P< 0.05) for Angora (2.16, 2.71, 2.82, 2.78, 3.20, and 3.13% body weight; SEM=0.161) and there were AT differences (P< 0.05) in digestion of organic matter (62.0, 65.4, 65.2, 67.1, 69.1, and 65.3%; SEM=1.29) and neutral detergent fiber (62.6, 67.4, 66.7, 68.3, 70.3, and 66.9%; SEM=1.35) but not nitrogen (61.6, 63.2, 63.7, 63.3, 65.7, and 60.3%; SEM=1.51) or ruminal methane emission (10.9, 12.8, 11.3, 11.1, 10.7, and 12.2% digestible energy for Angora, Boer, Spanish, Dorper, Katahdin, and St. Croix, respectively; SEM=0.97). In conclusion, all AT seemed resilient to WT regardless of mineral source and levels with TDS less than 10,000 mg/kg, although there were numerous differences among AT.