Laird, S, Kühn, I and Miller, HM orcid.org/0000-0003-1440-0454 (2018) Super-dosing phytase improves the growth performance of weaner pigs fed a low iron diet. Animal Feed Science and Technology, 242. pp. 150-160. ISSN 0377-8401
Abstract
This experiment was conducted to test the hypothesis that a super-dose of phytase would improve the performance of weaner pigs fed an Fe-deficient diet, through an increase in phytate bound-Fe bioavailability. A total of 234 pigs (initial BW 7.6 + SE 0.16 kg) were weaned at ∼28 d of age and blocked into mixed sex pens of 4 or 5 balancing for weight, sex and litter of origin. Treatments were arranged as a 3 × 2 factorial with 3 levels of phytase (0, 500 or 2500 FTU/kg feed) and 2 levels of Fe (50 [low; L-Fe] or 300 [high; H-Fe] mg/kg feed as FeSO₄) supplemented to an Fe-deficient wheat-SBM based diet. Diets were offered to 8 replicate pens for 20 d post-weaning. At the end of the experiment, 1 pig per pen was euthanized for the collection of blood, plasma, liver and ileal digesta. Pigs fed the L-Fe diet had a lower ADFI (P < 0.01) than those fed the H-Fe diet. Phytase at 2500 FTU/kg improved the ADG of L-Fe fed pigs to a level comparable with the H-Fe fed pigs; however, its effect was diminished when added to the H-Fe diet, resulting in a significant Fe x phytase interaction for ADG (P < 0.05). Reducing the dietary Fe level resulted in reductions in haemoglobin (P < 0.10), haematocrit (Hct; P < 0.001), plasma Fe and ferritin (P < 0.05), and liver Fe concentration (P < 0.001). Moreover, plasma transferrin was higher (P < 0.05) in L- Fe fed pigs. Supplementary phytase at 2500 FTU/kg tended to increase Hct concentration (P < 0.10) and numerically increased plasma Fe and ferritin but had no influence on other measured indices of Fe status. There was an Fe x phytase interaction for ileal InsP₆ degradation (P < 0.05), which mirrored that observed for ADG: phytase increased InsP₆ hydrolysis to a greater extent when added to the L-Fe than the H-Fe diet (68.2 vs 30.8%). These data demonstrate that high doses of phytase can effectively improve the performance of weaner pigs fed an Fe-deficient diet. The benefit of using high doses of phytase in diets rich in Fe is seemingly reduced, likely as a result of the ability of Fe to degrade phytase efficacy.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2018 Elsevier B.V. This is an author produced version of a paper published in Animal Feed Science and Technology. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Growth; Inositol phosphate; Iron; Pig; Phytase; Weaner |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Biology (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 02 Aug 2018 12:00 |
Last Modified: | 10 Jun 2019 00:44 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.anifeedsci.2018.06.004 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:134029 |