Table 10.

Effect of phytate source on standardized ileal digestibility (SID) of Ca and P and digestible Ca and P in the presence or absence of phytase (mean ± SE).

TRT	n	Phytase U/kg	Source	SID, %1		Digestible, %2
				Ca	P	Ca	P
2	14	0	Corn	43.00 ± 0.869	24.03 ± 0.732c	0.333 ± 0.0069	0.077 ± 0.0022d
5	7	0	Corn/SBM3	49.34 ± 1.227	32.46 ± 1.089b	0.415 ± 0.0103	0.106 ± 0.0034c
7	14	1,000	Corn	55.36 ± 0.869	87.47 ± 0.732a	0.429 ± 0.0069	0.280 ± 0.0022b
10	7	1,000	Corn/SBM	62.50 ± 1.227	91.02 ± 1.089a	0.525 ± 0.0103	0.298 ± 0.0034a
Main effects
Phytate source			Corn	49.18 ± 0.613		0.381 ± 0.0046	0.178 ± 0.0018
			Corn/SBM	55.92 ± 0.868		0.470 ± 0.0073	0.202 ± 0.0018
Phytase, U/kg			0	46.16 ± 0.751		0.374 ± 0.0060	0.091 ± 0.0018
			1,000	59.94 ± 0.751		0.477 ± 0.0060	0.289 ± 0.0018
P-values
Phytate source				<0.001	<0.001	<0.001	<0.001
Phytase				<0.001	<0.001	<0.001	<0.001
Phytate source × phytase				0.712	0.014	0.384	0.071

^a-dMeans within a column with different superscript letters differ (P < 0.05) based on Tukey HDS means separation. Main effects are shown and compared only when the interaction was not significant.

¹Standardized ileal Ca or P digestibilities. The non–diet-related endogenous Ca and P losses was determined with 6 pens in this experiment and used for determining standardized from apparent digestibilities and were 105.6 and 190.8 mg per kg DM intake, respectively.

²Digestible Ca and P determined by multiplying analyzed Ca or P in the diets by the digestibility of that nutrient.

³Phytate concentration in corn and corn/SBM-based diets were: 0.234 and 0.220%, respectively. Of the 0.220% analyzed phytate P in corn/SBM-based diet, 65% came from SBM (0.143%) and 35% (0.077%) from corn by formulation.