Table 4.

Effects of Bacillus subtilis supplementation and dietary Ca levels on breaking strength and thickness of eggshell.¹

Items		Breaking strength (N)		Thickness (× 0.01 mm)
		75 wk	79 wk	75 wk	79 wk
Ca level (%)	B. subtilis level (CFU/kg)
3.5	0	39.36	37.31	42.48	42.61
	2 × 109	38.84	38.22	42.27	43.25
4	0	38.92	37.93	42.67	43.43
	2 × 109	39.52	38.92	43.02	44.08
4.5	0	39.33	37.69	43.11	43.30
	2 × 109	39.46	38.24	42.82	43.56
SEM		0.34	0.18	0.13	0.11
Means of main effects
Ca level (%)
3.5		39.10	37.76	42.38	43.01b
4		39.22	38.42	42.85	43.70a
4.5		39.40	37.96	42.96	43.42a,b
B. subtilis level (CFU/kg)
0		39.21	37.64b	42.75	43.17b
2 × 109		39.27	38.46a	42.70	43.57a
P-value
Ca level		0.913	0.231	0.191	0.033
B. subtilis level		0.903	0.013	0.879	0.047
Ca level × B. subtilis level		0.821	0.862	0.530	0.632

^a,bMeans assigned different superscripts within a factor of analysis (Ca level, B. subtilis level, and their interactions) differ, P < 0.05.

¹Data are the mean of 8 replicates with 18 eggs each.