Effects of Supplementation with a Protease, Carbohydrases, and Phytase in Reduced Nutrient Diets Fed from Weaning to Market on Growth Performance, Nutrients Digestibility, Intestinal Morphology, and Hematological Characteristics.

To assess the impact of adding protease, alone or in combination with carbohydrases and phytase, on pig performance, weaned pigs (PIC 29 × 380, initial BW=6.8 ± 0.6 kg, n=328) were blocked by BW at weaning (21 ± 3 d) and randomly allotted to one of four feeding strategies during a 7 phase wean-to-finish period. The treatments consisted of adequate-nutrient diets (by phase, C); and reduced nutrient (decreased Soy, L-Met, Thr, and Trp) diets supplemented with either 1) 0.02% of Ronozyme® ProAct (protease, Pro); 2) 0.05% Victus (carbohydrases) plus 0.01% Pro (PV); or 3) PV plus increased Ronozyme® HiPhos (phytase, PVH). Pig weight and pen feed disappearance were measured by phase to calculate growth performance. Data were analyzed as RCBD using PROC Mixed of SAS and pen was the experimental unit. In the nursery period, supplementation with Pro, PV, or PVH maintained ADG, G:F, and BW; yet, ADFI was greater in PVH-fed compared to C-fed pigs. For the overall finisher period, ADG, ADFI, BW, and carcass composition were similar among treatments, but C-fed pigs tended to have greater G:F than those fed reduced nutrient diets. ATTD ash was greater in Pro-fed than C-fed pigs at the end of nursery phase 2, whereas white blood cell (WBC) count and hematocrit were greater on d 12 for pigs fed Pro, PV or PVH compared to those fed C. At the end of nursery Phase 3, ATTD DM tended (P = 0.07) to be greater in Pro-fed than C-fed pigs. The results indicate that supplementation with a combination of a protease, carbohydrases, and increased phytase can reduce the use of several common ingredients in swine diets and sustain growth performance, carcass quality, and nutrient digestibility.

	C	Pro	PV	PVH	SEM	P - Value
Nursery ADG, kg/d	0.29	0.29	0.29	0.31	0.015	0.22
Nursery ADFI, kg/d	0.42b	0.42b	0.42b	0.45a	0.018	0.05
Nursery G:F	0.69	0.68	0.69	0.68	0.013	0.93
End nursery BW, kg	15.85	15.80	15.70	16.39	0.790	0.24
Finisher ADG, kg/d	0.87	0.86	0.84	0.88	0.015	0.15
Finisher ADFI, kg/d	2.33	2.32	2.34	2.45	0.054	0.17
Finisher G:F	0.38x	0.37xy	0.36y	0.36xy	0.005	0.09
End BW, kg	137.4	135.9	133.7	139.7	2.48	0.15
Phase 2 ATTD ash, %	80.9a	82.2b	81.6ab	81.0a	0.42	0.05
d 12 WBC, k/µL	13.34b	18.15a	16.28ab	19.11a	1.25	0.03
d 12 Hematocrit, %	30.7y	32.2xy	34.2x	34.6x	1.08	0.07