Table 4.
Effect of standardized ileal digestible (SID) lysine and crude protein (CP) on performance and serum urea nitrogen of 72 to 104 kg barrows (Exp.1)1
| Normal-CP2 | SID lysine in low-CP2
|
SEM | p-value
|
||||||
|---|---|---|---|---|---|---|---|---|---|
| 0.51% | 0.61% | 0.71% | 0.81% | 0.91% | Linear | Quadratic | |||
| Weight gain (kg/d) | 0.88 | 0.82 | 0.85 | 0.92 | 0.91 | 0.89 | 0.04 | 0.04 | 0.08 |
| Feed intake (kg/d) | 2.70 | 2.55 | 2.55 | 2.68 | 2.64 | 2.63 | 0.12 | 0.43 | 0.72 |
| Feed conversion ratio | 3.05 | 3.12 | 3.02 | 2.91 | 2.90 | 2.96 | 0.07 | 0.02 | 0.02 |
| Daily SID lysine intake (g) | 19.2 | 13.0 | 15.6 | 19.0 | 21.4 | 23.9 | 0.87 | <0.01 | <0.01 |
| Serum urea nitrogen (mg/dl) | 21.6 | 16.0 | 15.6 | 15.1 | 14.0 | 15.3 | 0.98 | 0.21 | 0.31 |
1
A total of 120 barrows representing the mean of five pens per treatment and four pigs per pen for a 35 d trial.
2
Normal-CP and low-CP represent diets that were formulated to contain 15.3% CP with 0.71% SID lysine and 12% CP with SID lysine of 0.51, 0.61, 0.71, 0.81 and 0.91%.