Table 1.
Ingredient and chemical composition of the experimental diets (DM basis)
| Item | Roughage level, % of DM | |||
|---|---|---|---|---|
| 30 | 60 | |||
| −FAT | +FAT | −FAT | +FAT | |
| Ingredient, % of DM | ||||
| Wheat hay | 30.0 | 30.0 | 60.0 | 60.0 |
| Steam flaked corn | 46.3 | 42.8 | 17.3 | 13.8 |
| Wet corn gluten feed1 | 18.0 | 18.0 | 18.0 | 18.0 |
| Soybean meal | 3.00 | 3.00 | 2.00 | 2.00 |
| Urea | 0.20 | 0.20 | 0.20 | 0.20 |
| Yellow grease | - | 3.50 | - | 3.50 |
| Mineral and vitamin supplement2 | 2.50 | 2.50 | 2.50 | 2.50 |
| Analyzed composition, % | ||||
| Dry matter | 80.5 | 80.9 | 82.0 | 82.5 |
| Crude protein | 13.7 | 13.2 | 13.4 | 13.3 |
| Ether extract | 2.68 | 5.40 | 2.31 | 5.39 |
| Neutral detergent fiber | 29.6 | 32.0 | 46.1 | 44.5 |
| In vitro NDFD3 | 65.0 | 52.8 | 58.0 | 52.6 |
| Total digestible nutrients4 | 80.0 | 82.9 | 69.8 | 72.2 |
| ME, Mcal/kg4 | 2.96 | 3.07 | 2.57 | 2.67 |
| NEm, Mcal/kg4 | 1.99 | 2.08 | 1.66 | 1.75 |
| NEg, Mcal/kg4 | 1.34 | 1.41 | 1.05 | 1.12 |
1 Sweet Bran (Cargill Sweet Bran, Dalhart, TX).
2 Formulated to meet mineral and vitamin requirements for receiving calves according to NASEM (2016). Containing (DM basis): 7 mg/kg Co, 440 mg/kg Cu, 24 mg/kg I, 1060 mg/kg Mn, 6.6 mg/kg Se, 200 mg/kg/Zn, 97,000 IU/kg Vit. A, 12,320 IU/kg Vit. D, 1,672 IU/kg Vit. E.
3 In vitro neutral detergent fiber digestibility (in vitro NDFD) was determined after 48 h incubation using the two-stage method described by Tilley and Terry (1963).
4 Total digestible nutrients (TDN), metabolizable energy (ME), net energy for maintenance, and gain (NEm and NEg, respectively) were calculated based on tabular values from NASEM (2016).