Table 1.
Ingredient composition and nutrient profile of concentrate offered during the experiment (d 0 to 80)1
| Item | Day 0 to 7 | Day 8 to 19 | Day 20 to 30 | Day 31 to 80 |
|---|---|---|---|---|
| Ingredient (as-fed basis) | ||||
| Whole corn, kg/d | 0.91 | 2.27 | 4.09 | 5.23 |
| Soybean meal, kg/d | 0.36 | 0.36 | 0.55 | 0.68 |
| Mineral mix,2 kg/d | 0.05 | 0.05 | 0.05 | 0.05 |
| Nutrient profile3 (DM basis) | ||||
| TDN, % | 83 | 86 | 87 | 87 |
| NEm, Mcal/kg | 2.11 | 2.14 | 2.16 | 2.16 |
| NEg, Mcal/kg | 1.46 | 1.47 | 1.49 | 1.49 |
| NDF, % | 8.4 | 8.1 | 8.1 | 8.1 |
| ADF, % | 4.6 | 4.1 | 4.0 | 4.0 |
| CP, % | 20.3 | 14.3 | 13.7 | 13.5 |
Steers had free-choice access to orchardgrass (Dactylis glomerata L.) hay and water throughout the experimental period. Hay and concentrate were offered separately in different sections of the feed bunk.
Cattleman's Choice (Performix Nutrition Systems, Nampa, ID) containing 14% Ca, 10% P, 16% NaCl, 1.5% Mg, 3,200 mg/kg Cu, 65 mg/kg I, 900 mg/kg Mn, 140 mg/kg Se, 6,000 mg/kg Zn, 136,000 IU/kg vitamin A, 13,000 IU/kg vitamin D3, and 50 IU/kg vitamin E.
Based on nutritional profile of each ingredient, which were analyzed using wet chemistry procedures by a commercial laboratory (Dairy One Forage Laboratory, Ithaca, NY). Calculation for TDN used the equation proposed by Weiss et al. (1992), whereas NEm and NEg were calculated using the equations proposed by the NRC (1996).