Table 2.
Effects of low-protein diets on dry matter intake (DMI), average daily gain (ADG), feed efficiency (FE), and apparent total-tract digestibility of nutrients in growing goat kids.
| Crude Protein Level 1 | SEM | p-Value 2 | |||||
|---|---|---|---|---|---|---|---|
| 14.8% | 13.4% | 12.0% | T | L | Q | ||
| DMI, g/d | 657.5 | 664.9 | 672.9 | 15.21 | 0.78 | 0.48 | 0.99 |
| ADG, g/d | 114 a | 116 a | 97.3 b | 5.24 | 0.04 | 0.04 | 0.12 |
| FE | 0.173 a | 0.174 a | 0.145 b | 0.0079 | 0.02 | 0.02 | 0.12 |
| Intake, per kg Metabolic Weight (BW0.75) | |||||||
| OM, g/d | 49.6 b | 50.8 a,b | 54.4 a | 1.26 | <0.001 | 0.02 | 0.352 |
| CP, g/d | 8.51 a | 7.77 b | 7.40 b | 0.182 | <0.001 | <0.001 | 0.301 |
| NDF, g/d | 26.7 | 26.4 | 27.7 | 0.61 | 0.57 | 0.64 | 0.87 |
| ADF, g/d | 18.3 | 18.2 | 19.2 | 0.43 | 0.12 | 0.25 | 0.65 |
| Total Tract Apparent Digestibility, % | |||||||
| DM | 61.2 a | 60.5 a,b | 56.9 b | 0.97 | 0.004 | 0.002 | 0.22 |
| OM | 64.5 a,b | 65.9 a | 62.6 b | 0.85 | 0.02 | 0.11 | 0.03 |
| CP | 67.5 a | 66.3 a | 64.1 b | 0.85 | <0.001 | <0.001 | 0.81 |
| NDF | 55.3 a | 57.0 a | 52.6 b | 1.08 | 0.02 | 0.08 | 0.02 |
| ADF | 43.4 a,b | 46.3 a | 41.6 b | 1.32 | 0.04 | 0.34 | 0.02 |
Means within a row with different letters differ significantly (p < 0.05). 1 BW: body weight; DM: dry matter; OM: Organic matter; CP: Crude protein; NDF: Neutral detergent fiber; ADF: Acid detergent fiber. 2 T: Treatment; L: Linear; Q: Quadratic.