| Abstract | Effects of supplemental concentrate level and three sources of grass hay were determined to evaluate a method (www2.luresext.edu/goats/research/suppconc.html) of predicting impact of negative associative effects between feedstuffs on metabolizable energy (ME) intake by Boer goat wethers. Forage DM intake (g/kg BW0.75) was similar between growing and yearling wethers (34.9 and 30.8) and ranked 0 and 15 > 30 > 45 g/kg BW0.75 of concentrate dry matter (48.5, 41.8, 25.9, and 15.2, respectively). Age and concentrate level interacted in NDF digestibility (57.3, 60.6, 61.4, and 58.4% for growing and 56.6, 62.9, 56.8, and 30.0% for yearling wethers with 0, 15, 30, and 45 g/kg BW0.75, respectively). There was a tendency (P = 0.074) for an interaction in ME intake between age and concentrate level (361, 530, 634, and 709 for growing and 363, 547, 541, and 555 kJ/kg BW0.75 for yearling wethers with 0, 15, 30, and 45 g/kg BW0.75; values predicted for treatments with supplement were 563, 631, and 619 for growing and 575, 684, and 697 kJ/kg BW0.75 for yearling wethers with 15, 30, and 45 g/kg BW0.75, respectively. In conclusion, ME intake was accurately predicted for the low level of supplementation and moderate level with growing wethers. |
