Table 3.

Apparent duodenal digestibility (ADD), apparent ileal digestibility (AID), and apparent total tract digestibility (ATTD) of Ca and P in experimental diets containing 0, 750, 1,500, or 3,000 FTU/kg

	FTU1 per kilogram					P-value
Item	0	750	1,500	3,000	SEM	Linear	Quadratic
Ca
ADD, %	30.1	32.4	35.9	28.1	4.61	0.61	0.10
AID, %	55.1	71.4	75.4	79.0	2.28	<0.001	<0.001
ATTD, %	52.4	69.1	75.3	75.5	2.12	<0.001	<0.001
P
ADD, %	11.3	14.3	23.4	9.17	5.42	0.66	0.005
AID, %	26.6	49.7	59.4	69.0	1.91	<0.001	<0.001
ATTD, %	27.8	54.1	66.9	70.3	1.59	<0.001	<0.001

¹FTU = phytase units.