Table 7.

Effects of increasing concentrations of an E. coli phytase on the apparent total tract digestibility (ATTD) of microminerals in corn-soybean meal–based diets fed to growing pigs

Item			Phytase, FTU1 per kilogram complete feed				SEM	P-value2
	PC3	NC	500	1,000	2,000	4,000		PC vs. NC	Linear	Quadratic
Cu
Intake, mg/d	35.08	34.65	35.17	34.62	34.45	34.92	2.98	0.452	0.963	0.513
Fecal output, mg/d	23.72	23.03	20.97	21.26	20.59	23.50	2.25	0.651	0.404	0.043
Absorbed, mg/d	11.36	11.62	14.20	11.99	13.85	11.42	1.18	0.861	0.525	0.148
ATTD, Cu %	32.66	33.68	40.56	37.77	40.68	34.46	2.85	0.803	0.721	0.080
Fe
Intake, mg/d	478.82	310.13	295.43	270.02	297.95	282.84	27.33	<0.001	<0.001	0.007
Fecal output, mg/d	416.57	232.14	227.62	232.81	226.02	252.58	33.11	<0.001	0.185	0.337
Absorbed, mg/d	62.26	78.00	67.81	37.22	71.93	30.25	12.29	0.370	0.010	0.844
ATTD, Fe %	13.44	25.41	22.72	14.23	25.04	10.62	4.13	0.029	0.021	0.579
Mn
Intake, mg/d	127.86	126.31	128.19	126.18	125.55	127.28	10.88	0.452	0.963	0.513
Fecal output, mg/d	113.45	102.97	98.69	100.97	93.52	106.18	10.30	0.127	0.589	0.109
Absorbed, mg/d	14.41	23.33	35.15	25.21	32.03	21.10	4.53	0.171	0.349	0.154
ATTD, Mn %	11.59	18.61	27.76	20.32	25.92	16.40	3.79	0.198	0.346	0.141

Data are means of 8 observations per treatment, except for the diets containing 500 and 1,000 FTU of phytase only had 7 observations.

¹FTU = phytase units.

²Linear and quadratic contrasts of adding 500, 1,000, 2,000, or 4,000 FTU/kg phytase to the negative control diet.

³PC = positive control; NC = negative control.