Validation of the Extended Matrix Values for Energy and Amino Acids of a New Novel 6-Phytase, Natuphos E, in Weaned Piglets

The effect of using extended nutritional values for energy and amino acids (in addition to P and Ca nutritional values) for a novel 6-phytase (6-Phy; Natuphos E) was evaluated on the performance and bone mineralization of piglets. 144 weaned piglets ([Large White x Landrace] x Pietrain; 26 d of age; 7.6 kg BW) were randomly distributed by initial body weight into 48 pens (3 piglets per pen) according to a randomized block design with 8 blocks and 6 treatments. The experimental treatments consisted of: a positive control diet (PC), a negative control diet with reduced levels of energy, amino acids, Ca and P (NC) and the same NC diet supplemented with 250, 500 or 750 FTU/kg of 6-Phy or 500 FTU of a competitor’s phytase (COM). Between 0 to 22 and 22 to 46 d (PS/ST phases, respectively) PC diets were formulated to provide 14.03/13.82 MJ ME/kg, 12.50/11.50 g SID Lys/kg, and 3.80/3.30 g digP/kg and NC to provide 13.97/13.76 MJ ME/kg, 12.38/11.40 g SID Lys/kg, and 2.2/1.7 g digP/kg). Performance was measured at 22 and 46 d, and at the end of the trial, one piglet per pen was euthanized and the front left hoof was obtained to measure dry matter and ash contents in Os metacarpale III. No statistically significant differences among treatments were observed for performance parameters during the PS phase (see Table 00). In conclusion, performance was maintained for all doses tested, and bone mineralization was not affected with doses of 500 FTU and over, with the use of extended nutritional values for Natuphos E.

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

	PC	NC	250 FTU	500 FTU	750 FTU	COM	Root MSE	P-value
ADG 0 to 22, g	261	252	240	287	257	280	52	0.50
GFR 0 to 22	0.70	0.74	0.71	0.75	0.71	0.75	0.11	0.90
ADG 22 to 46, g	514b	445c	522b	531ab	573a	581a	49	<0.01
GFR 22 to 46	0.58b	0.57b	0.61ab	0.58b	0.62ab	0.64a	0.05	0.03
ADG 0 to 46, g	393b	352c	387bc	414ab	422ab	437a	37	<0.01
GFR 0 to 46	0.61	0.61	0.64	0.63	0.65	0.67	0.05	0.11
Bone ash, g	1.74a	1.24c	1.47b	1.69a	1.68a	1.68a	0.19	<0.01
Bone dry Wt, g	4.76	4.09	4.46	4.85	4.50	4.82	0.54	0.06