Table 5.

Hepatic enzyme levels and serum immunoglobulins of laying hens fed different lignocellulose levels at 38 wk of age.

Items	Supplementation amount (kg/ton of feed)				Pooled SEM	P-values
	0	0.5	1	2		Fixed	Linear	Quadratic
Hepatic enzyme levels (IU/L)
AST	169.7a	148.2b	158.2b	175.5a	12.8	<0.001	0.519	<0.001
ALT	19.7a	14.4b	15.8b	20.3a	1.4	<0.001	0.831	<0.001
Serum immunoglobulin levels (mg/dL)
IgY	129.2b	132.2a	134.4a	127.2b	1.9	<0.001	0.068	<0.001
IgA	31.0b	34.2a	35.8a	30.6b	1.7	<0.001	0.393	<0.001
IgM	8.2b	9.6ab	9.8a	8.5bb	1.0	0.001	0.985	<0.001

^a,b,cMeans bearing different superscripts within the same column are significantly different.

n: 20 samples per treatment group.

Abbreviations: AST, aspartate amino transferase; ALT, alanine amino transferase; IgY, immunoglobulin-Y; IgA, immunoglobulin-A; IgM, immunoglobulin-M.