Table 4.

Linear and quadratic relationship of dietary SID Lys and EAA:TN ratio on nitrogen (N) retention¹

	Ratio2	SID Lys, %						P-value
		0.82	0.92	1.02	1.12	1.22	SEM	Linear	Quadratic
N retained, g/d	0.36	14.5	15.9	17.1	17.8	17.7	0.36	<0.0001	0.02
	0.33	14.6	15.9	17.3	17.9	19.1	0.38	<0.0001	0.51

¹Data presented are least-square means (n = 8 pigs/treatment).

²E:T ratios of 0.36 (high ratio diets) and 0.33 (low ratio diets) reflect the amount of N in the diets coming from essential amino acids (E) and from all other components (T), with the higher ratio having a larger contribution of N from essential amino acids.

E:T, essential amino acid nitrogen to total nitrogen ratio; N, nitrogen; SEM, standard error of the mean; SID, standardized ileal digestible.