Table 5.

Effects of different ZnO sources on Zn concentration of feces and serum in weanling pigs

Item	CL1)	HME1) (ppm)			P-ZnO1)	SEM	Contrasts2) (p-value)
		500	1,000	2,500			CL vs others	HME vs P-ZnO	L	Q
Phase I (d 14)
Feed (mg/kg DM)	179	721	1,219	2,688	2,694	-	-	-	-	-
Feces (μg/g)	1,068	4,297	6,936	13,659	17,364	173	<0.001	<0.001	<0.001	<0.001
Zn digestibility	28.1	29.2	34.2	41.6	19.0	2.7	0.181	<0.001	<0.001	0.521
Serum (μg/mL)	1.58	2.58	2.72	2.79	2.74	0.1	<0.001	0.734	<0.001	<0.001
Phase II (d 28)
Feed (mg/kg DM)	204	730	1,211	2,628	2,699	-	-	-	-	-
Feces (μg/g)	1,172	4,101	7,060	12,866	17,020	121	<0.001	<0.001	<0.001	<0.001
Zn digestibility	32.1	34.2	30.6	44.2	20.1	2.9	0.465	<0.001	<0.001	0.479
Serum (μg/mL)	1.91	3.07	2.85	3.66	3.04	0.11	<0.001	0.249	<0.001	0.169

HME, hot melt extrusion; SEM, standard error of means; DM, dry matter.

¹⁾CL, basal diet without ZnO; HME, basal diet with 500, 1,000, and 2,500 ppm Zn as HME-ZnO; P-ZnO, basal diet with 2,500 ppm Zn as ZnO.

²⁾Linear (L) and quadratic (Q) effects of HME concentrations.