SUPPLEMENTATION OF AN AMMONIATED WHEAT STRAW-ALFALFA HAY DIET

The effect of equal energy supplementation by corn (Zea MaYs L.) or corn gluten feed (CGF) on an ammoniated wheat (Triticum aestivum L.) straw-alfalfa (Medicago sativa L.) hay ration was determined by digestibility and growth trials. A completely randomized design digestibility trial was conducted with 12 Angus (Bos taurus) heifers (400-600 lb) individually fed a diet of ad libitum ammoniated wheat straw and 0.55% body weight of alfalfa hay plus (i) no supplement (control), (ii) 0.79% body weight cracked corn (corn) or (iii) 0.95% body weight of pelleted dry CGF. Supplementation increased (P < 0.01) dry matter (DM) intake and digestibility (8.3, 11.9, and 11.9 lb/d and 36.5, 48.5, and 57.3% for control, corn and CGF, respectively). Thirty Gelbvieh sired steers (696 lb) were used in a 112 d randomized complete block design growth trial to evaluate an ammoniated wheat-straw-alfalfa hay ration with or without additional supplemental energy from corn or CGF. Treatments were ad libitum ammoniated wheat straw and 4.5 lb alfalfa hay per day plus (i) control, (ii) 6.4 lb/d of corn, or (iii) 7.5 lb/d of pelleted CGF. Treatments ii and iii were designed to provide the same amount of supplemental energy. Supplementation increased (P < 0.01) ADG (0.64, 2.05, and 2.86 lb/d, for control, corn, and CGF, respectively).