Effect of a New 6-Phytase, Natuphos E, on Piglet Performance, Ileal Digestibility and Bone Mineralization

The efficacy of a new phytase product (Natuphos E) at different doses was evaluated on performance, nutrient digestibility and bone mineralization of piglets. 120 newly weaned piglets ([Duroc x Landrace] x Pietrain; 26 d of age; 7.3 kg BW) were randomly distributed by initial body weight into 40 pens (3 piglets per pen) according to a randomized block design with 8 blocks and 5 treatments. Experimental treatments consisted of a positive control diet (PC) with adequate levels of Ca and P, a negative control basal diet (NC) with limiting levels of Ca and P, and the same NC diet supplemented with 125, 250 or 500 FTU/kg of Natuphos E. Performance was measured at 21 and 42 d. Between d 18 to 21, fresh feces were obtained from each pen and the apparent total tract digestibility (ATTD) of ash, Ca and P was measured using TiO₂ as indigestible marker. Finally, at d 42, one piglet per pen was euthanized and the front left hoof was obtained to measure dry matter and ash contents in Os metacarpale III. Phytase supplementation improved performance, mineral ATTD and bone mineralization in NC, and similar values to PC were achieved (see Table 00). In conclusion, the new phytase under study improves performance, Ca and P digestibility, and bone mineralization in piglets fed Ca and P limiting diets.

Table 00. Average daily growth, gain to feed ratio, nutrient ATTD and bone ash content and weight

	PC	NC	125 FTU	250 FTU	500 FTU	Root MSE	P-value
ADG 0 to 21, g	270	241	293	257	285	48	0.23
GFR 0 to 21	0.70	0.63	0.74	0.69	0.69	0.07	0.06 Q
ADG 21 to 42, g	527ab	418c	494b	493b	559a	40	<0.01 L
GFR 21 to 42	0.62a	0.57b	0.62a	0.59ab	0.62a	0.03	0.04 L
ADG 0 to 42, g	398ab	329c	393ab	375b	422a	38	<0.01 L
GFR 0 to 42	0.64a	0.59b	0.66a	0.62ab	0.64a	0.04	0.01
ATTD ash, %	59.2b	58.1b	59.2b	64.0a	65.9a	3.7	<0.01 L
ATTD Ca, %	54.2bc	51.3c	57.9b	69.3a	68.6a	4.3	<0.01 L,Q
ATTD P, %	41.2a	9.8d	21.0c	33.3b	42.0a	6.8	<0.01 L,Q
Bone ash, g	1.12a	0.56d	0.78c	0.88bc	1.03ab	0.14	<0.01 L
Bone dry Wt, g	2.65ab	1.85c	2.37b	2.46ab	2.81a	0.36	<0.01 L

^{L, Q} = linear and quadratic response to phytase addition in NC diets