Table 6.

Effects of increasing concentrations of an E. coli phytase on the apparent total tract digestibility (ATTD) of macrominerals, and retention of Ca and P 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
Ca
Intake, g/d	12.35	7.36	7.33	7.93	8.22	8.40	0.73	<0.001	<0.001	0.002
Fecal output, g/d	3.75	2.63	1.40	1.19	1.15	1.21	0.20	<0.001	<0.001	<0.001
Absorbed, g/d	8.60	4.73	5.94	6.73	7.06	7.18	0.66	<0.001	<0.001	<0.001
ATTD, Ca %	69.61	64.14	80.94	85.07	85.90	85.37	2.04	0.065	<0.001	<0.001
Urine output, g/d	3.91	17.21	4.83	6.90	4.04	4.99	3.71	0.003	0.046	0.034
Retention, g/d	7.17	1.30	4.97	5.35	6.26	6.18	1.17	<0.001	<0.001	<0.001
Retention, %	59.94	16.65	67.38	71.46	75.71	73.28	10.09	0.001	0.002	0.001
P
Intake, g/d	8.89	5.82	5.57	5.52	5.61	5.73	0.52	<0.001	0.789	0.007
Fecal output, g/d	4.08	3.35	1.71	1.56	1.30	1.39	0.27	0.001	<0.001	<0.001
Absorbed, g/d	4.81	2.36	3.86	3.96	4.32	4.34	0.29	<0.001	<0.001	<0.001
ATTD, P %	54.34	42.44	69.36	71.82	76.93	75.65	1.93	<0.001	<0.001	<0.001
Urine output, mg/d	115.40	92.97	62.13	106.72	183.14	63.08	36.23	0.656	0.960	0.038
Retention, g/d	4.69	2.26	3.80	3.85	4.13	4.27	0.31	<0.001	<0.001	<0.001
Retention, %	53.05	40.77	68.23	69.72	73.59	74.51	1.90	<0.001	<0.001	<0.001
Na
Intake, g/d	2.74	2.24	2.62	2.65	2.79	2.48	0.22	<0.001	0.008	<0.001
Fecal output, g/d	1.20	1.06	1.07	0.94	0.64	0.68	0.55	0.704	0.148	0.492
Absorbed, g/d	1.54	1.17	1.55	1.71	2.15	1.80	0.37	0.318	0.076	0.029
ATTD, Na %	57.75	54.04	61.20	65.20	77.85	73.65	18.94	0.779	0.101	0.229
K
Intake, g/d	14.24	13.91	13.54	14.26	13.45	14.39	1.19	0.147	0.032	0.033
Fecal output, g/d	2.69	2.28	1.85	1.81	1.46	1.82	0.29	0.063	0.050	0.002
Absorbed, g/d	11.55	11.63	11.69	12.46	11.83	12.57	0.92	0.789	0.005	0.890
ATTD, K %	81.27	83.66	86.36	87.36	88.05	88.45	1.18	0.113	0.006	0.050
Mg
Intake, g/d	2.35	2.34	2.29	2.27	2.29	2.34	0.20	0.762	0.446	0.054
Fecal output, g/d	1.69	1.63	1.38	1.41	1.34	1.46	0.21	0.608	0.426	0.025
Absorbed, g/d	0.66	0.71	0.91	0.86	0.96	0.88	0.07	0.627	0.206	0.050
ATTD, Mg %	28.67	30.50	36.53	38.43	42.24	37.43	3.60	0.668	0.142	0.014
S
Intake, g/d	3.72	3.41	3.43	3.62	3.57	3.53	0.30	<0.001	0.078	0.007
Fecal output, g/d	0.82	0.73	0.70	0.74	0.70	0.77	0.07	0.060	0.334	0.505
Absorbed, g/d	2.90	2.69	2.73	2.88	2.86	2.76	0.24	<0.001	0.242	<0.001
ATTD, S %	78.07	78.75	79.59	79.50	80.31	78.23	0.85	0.576	0.525	0.101

Data are means of 8 observations per treatment, except for the positive and negative control diets that had only 6 observations, and diets containing 2,000 and 4,000 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.