Table 5. Polynomial orthogonal contrasts of dose response to methionine supplementation

Contrast	DF	Contrast SS	Mean square	F-value	Pr > F
Linear	1	0.619	0.619	6.20	0.022
Quadratic	1	0.039	0.039	0.39	0.538
Cubic	1	0.027	0.027	0.27	0.608

DF, degrees of freedom; SS, sum of squares.