Table 6. Effects of different dietary copper (Cu) sources and levels on jejunal morphology in growing pigs (n = 6/treatment)

Cu source	Added Cu level (mg/kg)	Villus height (μm)	Crypt depth (μm)	Villus:crypt (μm/μm)
CuSO4	0	510.89	184.17	2.96
	50	595.36	159.62	4.13
	100	459.72	178.99	2.69
CuAA	0	510.89	184.17	2.96
	50	525.43	174.98	3.08
	100	558.81	185.78	3.34
CuHMB	0	510.89	184.17	2.96
	50	600.48	187.03	3.22
	100	530.59	167.87	3.31
SEM		37.10	20.26	0.39
p-value for source × level		0.400	0.854	0.896
Main effect of source
CuSO4		521.99	174.26	3.26
CuAA		531.71	181.64	3.13
CuHMB		547.32	179.69	3.16
SEM		22.43	11.17	0.23
p-value for source		0.724	0.890	0.918
Main effect of level
	0	510.89	184.17	2.96
	50	573.76	173.88	3.48
	100	516.37	177.54	3.11
SEM		21.49	11.15	0.23
p-value for level		0.082	0.804	0.261

CuSO₄, copper sulfate; CuAA, Cu-amino acid complex; CuHMB, Cu-hydroxy-4-methylthio butanoate chelate complex.