250 Key drivers of a new multi-carbohydrase and phytase complex value for growing-finishing pigs: energy or amino acids?

Abstract

Abstract This study aimed to investigate the effects of reductions in energy and amino acids on the efficacy of supplementing corn-wheat-soybean meal diets with a multi-carbohydrase and phytase complex (MCPC) on growth performance and ATTD of energy and nutrients. A total of 700 pigs (BW = 29.5; SD = 4.2 kg) were housed in 70 pens and fed 5 diets (14 pens/diet). Diets were positive control (PC); and negative control 1 (NC1) or negative control 2 (NC2) without or with MCPC. The PC diet was adequate in nutrients according to NRC (2012). Relative to this PC diet, both NC diets were similarly reduced in digestible P (-0.134% unit) and calcium (-0.12% unit) and were differently reduced in NE and dig. AA (NC1 = -173 kcal/kg and -5% dig. AA and NC2 = -124 kcal/kg and -7% dig. AA). Fecal samples were collected from each pen at around 50 kg of BW. Final BW, ADG and feed conversion ratio were impaired (P < 0.05) with the lower nutrient specifications (NC1 and NC2) in comparison with the PC diet. ADFI did not differ among treatments. MCPC supplementation improved the final BW (+2.2%, P = 0.05), ADG (+2.8%, P = 0.05) and feed conversion ratio (-3.3%, P = 0.001). Compared with PC diet, ATTD of DM, OM, CP, EE, energy, Ca and P were reduced in pigs fed NC diets (P < 0.05). The addition of MCPC improved the ATTD of DM (P = 0.001), OM (P = 0.02), CP (P < 0.0001), energy (P = 0.01), Ca (P < 0.0001), and P (P < 0.0001). The present study indicates that the MCPC supplementation was efficient to compensate the dietary protein and amino acid reductions (up to 7%). However, the reduction in dietary energy should be limited below 5% to guarantee feed efficiency and optimal performance.