Table 6.

Tibia weight, tibia length, Seedor Index, breaking strength, and tibial bone densitometry of white laying hens fed different sources and levels of trace minerals from 78 to 98 weeks of age.

Item	Bone characteristics				Tibial bone densitometry
	Tibia weight, mg	Tibia length, mm	Seedor index	Bone strength, N	Proximal, mg/cm3	Medial, mg/cm3	Distal, mg/cm3	Average, mg/cm3
ZMCGly source	7601B	113.6	21.9	278.9	720.0	694 .9B	705.3	703.0
ZMCAA source	7882A	113.7	22.9	287.6	732.8	820.2A	729.5	760.8
Low level	7759	113.8	22.3	271.5	727.9	744.0	670.9	714.3
High level	7722	113.5	22.6	294.2	724.9	779.5	770.4	754.8
P-value
Source	0.038	0.889	0.057	0.174	0.720	0.003	0.505	0.114
Level	0.781	0.691	0.573	0.615	0.933	0.460	0.030	0.310
Source × Level	0.856	0.488	0.345	0.990	0.406	0.439	0.006	0.449
SEM	66.1	0.30	1.46	7.98	18.34	22.37	25.12	17.75

TW = tibia weight; TL = tibia length; SI = Seedor index; BS = breaking strength; SEM = standard error of the mean.

ZMCGly = Zn, Mn, and Cu bis-glycinates.

ZMCAA = Zn, Mn, and Cu amino acid complexed minerals.

Low level = 20, 20, and 3.5 mg of Zn, Mn, and Cu, respectively.

High level = 40, 40, and 7 mg of Zn, Mn, and Cu, respectively.

^A,B Within a column, values with different letters differ significantly from the source by Tukey's test (P < 0.05).