Effect of a novel phytase on growth performance, bone ash, and mineral digestibility in nursery and grower-finisher pigs.
To compare the effectiveness of 2 phytase enzymes (Phyzyme and Natuphos), growth performance, fibula ash, and Ca and P digestibilities were evaluated in 4 studies. The first 3 studies used 832 pigs (i.e., 288 in the nursery phase, initial BW 8.1 kg; 288 in the grower phase, initial BW 24.2 kg; and 256 in the finisher phase, initial BW 57.8 kg) and were carried out over periods of 28, 42, and 60 d, respectively. Dietary treatments in each study consisted of a positive control [available P (aP) at requirement level]; negative control (Ca remained as in the positive control, and aP at 66, 56, and 40% of the requirement for the nursery, grower, and finisher studies, respectively); negative control plus graded levels of Phyzyme [250, 500, 750, or 1,000; measured as phytase units (FTU)/kg] or Natuphos (250 and 500 FTU/kg for the nursery and grower studies, or 500 and 1,000 FTU/kg for the finisher study) plus a very high dose of Phyzyme (tolerance level, at 10,000 FTU/kg) in the nursery and grower experiments. Across the 3 studies, there was no effect of any dietary treatment on ADFI, but the negative control reduced ADG (10%), G:F (7%), and bone ash (8%) compared with the positive control. In the nursery study, phytase addition increased G:F and bone ash linearly (P < 0.01). In the grower study, phytase increased ADG, G:F, and bone ash linearly (P < 0.01). In the finisher study, phytase addition increased ADG and bone ash linearly (P < 0.01) and increased G:F quadratically (P < 0.05); G:F was, on average, 5% greater (P < 0.05) with Phyzyme than with Natuphos. The fourth study was conducted to investigate the P-releasing efficacy of the 2 phytases. The apparent fecal digestibility of P, measured with chromic oxide as an external marker in 35 pigs (55.9 kg of BW), showed that aP increased (P < 0.001) by 0.17 and 0.06 g (+/- 0.023) per 100 FTU consumed for Phyzyme and Natuphos, respectively. Also, Phyzyme at 10,000 FTU/kg was not detrimental to animal health or growth performance. At doses intended for commercial conditions, Phyzyme proved to be effective in releasing phytate bound P from diets, with an efficacy superior to a commercially available enzyme.
Braña
D V
DV
Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
Ellis
M
M
Castañeda
E O
EO
Sands
J S
JS
Baker
D H
DH
D010832:6-Phytase / Q000494:pharmacology*; D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D015519:Bone Density; D001842:Bone and Bones / Q000737:chemistry / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D004032:Diet / Q000662:veterinary; D004063:Digestion / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D010758:Phosphorus / Q000378:metabolism; D012568:Schizosaccharomyces; D013552:Swine / Q000254:growth & development*; D015430:Weight Gain / Q000187:drug effects*
D010758:Phosphorus; D010832:6-Phytase; D002118:Calcium