Table 1.
Average nutritional composition1 of concentrate (days 0 to 168) and stargrass hay (days 89 to 168)
| Concentrate2 | Hay | |||
|---|---|---|---|---|
| Item | Year 1 | Year 2 | Year 1 | Year 2 |
| DM, % | 87.2 | 94.1 | 95.4 | 92.3 |
| CP, % | 22.5 | 21.8 | 5.60 | 9.00 |
| Crude fat, % | — | — | — | — |
| ADF, % | 27.3 | 30.4 | 43.4 | 45.8 |
| NDF, % | 42.5 | 44.4 | 79.7 | 75.1 |
| TDN3, % | 74.0 | 73.0 | 52.0 | 55.0 |
| NEm4, Mcal/kg | 1.74 | 1.71 | 0.90 | 1.01 |
| NEg4, Mcal/kg | 1.12 | 1.10 | 0.35 | 0.46 |
| Ca, % | 0.96 | 0.91 | 0.19 | 0.25 |
| P, % | 0.59 | 0.46 | 0.14 | 0.19 |
| Mg, % | 0.25 | 0.25 | 0.31 | 0.14 |
| K, % | 1.65 | 1.38 | 0.55 | 1.16 |
| Na, % | 0.07 | 0.06 | 0.04 | 0.02 |
| S, % | 0.35 | 0.30 | 0.12 | 0.13 |
| Fe, mg/kg | 211 | 210 | 74.0 | 35.0 |
| Zn, mg/kg | 47.0 | 48.0 | 17.0 | 30.0 |
| Cu, mg/kg | 12.0 | 9.00 | 6.00 | 3.00 |
| Mn, mg/kg | 30.0 | 31.0 | 20.0 | 35.0 |
| Mo, mg/kg | 2.30 | 1.60 | 0.30 | 0.30 |
1Samples of concentrate and hay were collected every 28 d from days 0 to 168 and 89 to 168, respectively. All samples were pooled within each year and sent in duplicates to a commercial laboratory (Dairy One Forage Laboratory, Ithaca, NY) for wet chemistry analyses.
2As-fed basis: 23% soybean hulls, 22% soybean meal, 22% dried distillers grains, 15% cottonseed hulls pellets, 15% cracked corn, 2% Ca carbonate, and 1% sugarcane molasses (United Feed Company, Okeechobee, FL 34972).
3Calculated as described by Weiss et al. (1992).
4Calculated using the equations proposed by NRC (2000).