Effect of supplemental protein source on performance of Spanish x Boer wethers

S. A. Soto-Navarro, A. L. Goetsch, T. Sahlu, and R. Puchala

E (Kika) de la Garza Institute for Goat Research, Langston University, Langston, OK

Fifty weaned Spanish x Boer wethers goats (27 ± 4.0 kg initial BW and 6.5 to 7.5 mo of age) were used in an experiment with 5 x 2 factorial arrangement of treatments to determine effects on growth of five sources (blood, corn gluten, feather, fish, and soybean meals) of ruminally undegraded intake protein (UIP) in 70% concentrate diets. Diets were formulated to be 13 or 19% CP and similar in UIP and the ratio of ruminally degraded intake protein to TDN within protein level. Ad libitum DM intake in the 27-wk experiment (1,043, 1,089, 1,153, 1,086, and 1,112 g/day; SE = 74.4) and ADG (136, 134, 143, 145, and 138 g for blood , corn gluten, feather, fish, and soybean meals, respectively; SE = 9.8) were similar between CP levels and among UIP sources. The ADG:DM intake ratio over the entire 27-wk period was similar among treatments. However, in the first 18 wk the ratio was greater (P < 0.05) for fish meal than for corn gluten, feather, and soybean meals (138, 1216, 124, 154, and 127 g/kg for blood, corn gluten, feather, fish, and soybean meals, respectively; SE = 8.3). In summary, with a dietary concentrate level of 70% and at least 13% CP, differences in amino acid profiles among blood, corn gluten, feather, fish, and soybean meals did not impact the rate or efficiency of growth by weaned Boer x Spanish wethers in a 27-wk period. However, fish meal improved efficiency of growth in the first 18 wk relatively to corn gluten, feather, and soybean meals.