<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>2224-7920</journal-id>
<journal-title><![CDATA[Revista de Producción Animal]]></journal-title>
<abbrev-journal-title><![CDATA[Rev. prod. anim.]]></abbrev-journal-title>
<issn>2224-7920</issn>
<publisher>
<publisher-name><![CDATA[Ediciones Universidad de Camagüey]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S2224-79202019000300034</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Suplementación de selenio y actividad de la enzima glutatión peroxidasa en suero sanguíneo en cerdos: un metanálisis]]></article-title>
<article-title xml:lang="en"><![CDATA[Selenium supplementation and glutathione peroxidase enzyme activity in blood serum in pigs: a meta-analysis]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Quisirumbay-Gaibor]]></surname>
<given-names><![CDATA[Jimmy]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
<xref ref-type="aff" rid="Aaf"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Vílchez Perales]]></surname>
<given-names><![CDATA[Carlos]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Universidad Nacional Agraria La Molina Escuela de Posgrado ]]></institution>
<addr-line><![CDATA[Lima ]]></addr-line>
<country>Perú</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Universidad Central del Ecuador Facultad de Medicina Veterinaria y Zootecnia Ciudadela Universitaria]]></institution>
<addr-line><![CDATA[Quito ]]></addr-line>
<country>Ecuador</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>12</month>
<year>2019</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>12</month>
<year>2019</year>
</pub-date>
<volume>31</volume>
<numero>3</numero>
<fpage>34</fpage>
<lpage>48</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_arttext&amp;pid=S2224-79202019000300034&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_abstract&amp;pid=S2224-79202019000300034&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.sld.cu/scielo.php?script=sci_pdf&amp;pid=S2224-79202019000300034&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen  Antecedentes:  La evaluación de la actividad de la enzima glutatión peroxidasa (GSH-Px) como indicador de los niveles de selenio (Se) ha sido extensivamente estudiada con resultados variables entre estudios. El objetivo de este artículo fue determinar el efecto de la suplementación de Se sobre la actividad de GSH-Px medida en suero sanguíneo y el posible impacto de otros nutrientes dietéticos y elementos del diseño experimental sobre la variable respuesta.  Métodos:  Se utilizó la técnica de metanálisis bajo el modelo de efectos aleatorios que incluyó tamaño de efecto, heterogeneidad, metaregresión y sesgo de publicación.  Resultados:  La suplementación dietética de selenio incrementa (P &lt; 0,00001) la actividad enzimática en el análisis general (0,326 unidades.mL-1) como cuando las fuentes suplementadas fueron inorgánica (0,327 unidades.mL-1), orgánica (0,325 unidades.mL-1), en lechones (0,261 unidades.mL-1) y cerdos en crecimiento-finalización (0,328 unidades.mL-1). El efecto de la suplementación sobre la actividad de la enzima no se presentó de manera consistente entre los estudios como lo reflejan los valores en la prueba de inconsistencia (&gt; 95 %). En las metaregresiones se determinó que la actividad de GSH-Px se ve afectada (P &lt; 0,001) por número de repeticiones por tratamiento, número de individuos por unidad experimental, número de individuos muestreados por unidad experimental, nivel de selenio, cobre, zinc, vitaminas A y E en el alimento.  Conclusiones:  De esta investigación se concluye que la suplementación dietética de Se, favorece la actividad de GSH-Px medida en suero y que existen varios factores relacionados al diseño experimental y otros nutrientes con función antioxidante que afectan la variable en estudio.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract  Background:  The evaluation of the activity of the enzyme glutathione peroxidase (GSH-Px) as an indicator of selenium levels (Se) has been extensively studied with varying results between studies. The objective of this article was to determine the effect of Se supplementation on the activity of GSH-Px measured in blood serum and the possible impact of other dietary nutrients and experimental design elements on the response variable.  Methods:  The meta-analysis technique was used under the random effects model that included effect size, heterogeneity, metaregression and publication bias.  Results:  Dietary selenium supplementation increases (P &lt; 0.00001) the enzymatic activity in general analysis (0.326 Units.mL-1) as when the supplemented sources were inorganic (0.327 Units.mL-1), organic (0.325 Units.mL-1), in piglets (0,261 Units.mL-1) and pigs in growth-completion (0,328 Unida-des.mL-1). The effect of supplementation on enzyme activity was not presented consistently among studies as reflected in the values in the inconsistency test (&gt; 95 %). In the meta-regressions it was determined that the activity of GSH-Px is affected (P &lt; 0.001) by number of repetitions per treatment, number of individuals per experimental unit, number of individuals sampled per experimental unit, selenium level, copper, zinc, vitamins A and E in food.  Conclusions:  From this research it is concluded that the dietary supplementation of the GSH-Px activity measured in serum is favored and that there are several factors related to the experimental design and other nutrients with antioxidant function that affect the variable under study.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[nutrición]]></kwd>
<kwd lng="es"><![CDATA[alimentación]]></kwd>
<kwd lng="es"><![CDATA[porcinos]]></kwd>
<kwd lng="es"><![CDATA[antioxidantes]]></kwd>
<kwd lng="es"><![CDATA[minerales]]></kwd>
<kwd lng="en"><![CDATA[nutrition]]></kwd>
<kwd lng="en"><![CDATA[food]]></kwd>
<kwd lng="en"><![CDATA[pigs]]></kwd>
<kwd lng="en"><![CDATA[antioxidants]]></kwd>
<kwd lng="en"><![CDATA[minerals]]></kwd>
</kwd-group>
</article-meta>
</front><back>
<ref-list>
<ref id="B1">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Aaron]]></surname>
<given-names><![CDATA[D. K.]]></given-names>
</name>
<name>
<surname><![CDATA[Hays]]></surname>
<given-names><![CDATA[V. W]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[How many pigs? Statistical power considerations in swine nutrition experiments]]></article-title>
<source><![CDATA[Journal of animal science]]></source>
<year>2004</year>
<volume>82</volume>
<numero>13</numero>
<issue>13</issue>
<page-range>245-54</page-range></nlm-citation>
</ref>
<ref id="B2">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Adkins]]></surname>
<given-names><![CDATA[R. S.]]></given-names>
</name>
<name>
<surname><![CDATA[Ewan]]></surname>
<given-names><![CDATA[R. C]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effects of selenium on performance, serum selenium concentration and glutathione peroxidase activity in pigs]]></article-title>
<source><![CDATA[Journal of animal science]]></source>
<year>1984</year>
<volume>58</volume>
<numero>2</numero>
<issue>2</issue>
<page-range>346-50</page-range></nlm-citation>
</ref>
<ref id="B3">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ahsan]]></surname>
<given-names><![CDATA[U]]></given-names>
</name>
<name>
<surname><![CDATA[Kamran]]></surname>
<given-names><![CDATA[Z]]></given-names>
</name>
<name>
<surname><![CDATA[Raza]]></surname>
<given-names><![CDATA[I]]></given-names>
</name>
<name>
<surname><![CDATA[Ahmad]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
<name>
<surname><![CDATA[Babar]]></surname>
<given-names><![CDATA[W]]></given-names>
</name>
<name>
<surname><![CDATA[Riaz]]></surname>
<given-names><![CDATA[M. H]]></given-names>
</name>
<name>
<surname><![CDATA[Iqbal]]></surname>
<given-names><![CDATA[Z]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Role of selenium in male reproduction-A review]]></article-title>
<source><![CDATA[Animal reproduction science]]></source>
<year>2014</year>
<volume>146</volume>
<numero>1-2</numero>
<issue>1-2</issue>
<page-range>55-62</page-range></nlm-citation>
</ref>
<ref id="B4">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Almad]]></surname>
<given-names><![CDATA[H]]></given-names>
</name>
<name>
<surname><![CDATA[Tian]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
<name>
<surname><![CDATA[Wang]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Khan]]></surname>
<given-names><![CDATA[M. A]]></given-names>
</name>
<name>
<surname><![CDATA[Wang]]></surname>
<given-names><![CDATA[Y]]></given-names>
</name>
<name>
<surname><![CDATA[Zhang]]></surname>
<given-names><![CDATA[L]]></given-names>
</name>
<name>
<surname><![CDATA[Wang]]></surname>
<given-names><![CDATA[T]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effects of dietary sodium selenite and selenium yeast on antioxidant enzyme activities and oxidative stability of chicken breast meat]]></article-title>
<source><![CDATA[Journal of agricultural and food chemistry]]></source>
<year>2012</year>
<volume>60</volume>
<numero>29</numero>
<issue>29</issue>
<page-range>7111-20</page-range></nlm-citation>
</ref>
<ref id="B5">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[I. Kipper]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<name>
<surname><![CDATA[Lehnen]]></surname>
<given-names><![CDATA[C. R]]></given-names>
</name>
<name>
<surname><![CDATA[Demori]]></surname>
<given-names><![CDATA[A. B]]></given-names>
</name>
<name>
<surname><![CDATA[Remus]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[Lovatto]]></surname>
<given-names><![CDATA[P. A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Meta-analysis of the relationship between ractopamine and dietary lysine levels on carcass characteristics in pigs]]></article-title>
<source><![CDATA[Livestock Science]]></source>
<year>2012</year>
<volume>143</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>91-6</page-range></nlm-citation>
</ref>
<ref id="B6">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Apple]]></surname>
<given-names><![CDATA[J. K. Rincker]]></given-names>
</name>
<name>
<surname><![CDATA[P. J. McKeith]]></surname>
<given-names><![CDATA[F. K. Carr]]></given-names>
</name>
<name>
<surname><![CDATA[S. N. Armstrong]]></surname>
<given-names><![CDATA[T. A.]]></given-names>
</name>
<name>
<surname><![CDATA[Matzat]]></surname>
<given-names><![CDATA[P. D]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Meta-analysis of the ractopamine response in finishing swine]]></article-title>
<source><![CDATA[The Professional Animal Scientist]]></source>
<year>2007</year>
<volume>23</volume>
<numero>3</numero>
<issue>3</issue>
<page-range>179-96</page-range></nlm-citation>
</ref>
<ref id="B7">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Bansal]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Simon]]></surname>
<given-names><![CDATA[M. C]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Glutathione metabolism in cancer progression and treatment resistance]]></article-title>
<source><![CDATA[Journal of Cell Biology]]></source>
<year>2018</year>
<volume>217</volume>
<numero>7</numero>
<issue>7</issue>
<page-range>2291-8</page-range></nlm-citation>
</ref>
<ref id="B8">
<nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Bax]]></surname>
<given-names><![CDATA[L]]></given-names>
</name>
</person-group>
<source><![CDATA[MIX 2.0 - Professional software for meta-analysis in Excel]]></source>
<year>2016</year>
</nlm-citation>
</ref>
<ref id="B9">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Borenstein]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Hedges]]></surname>
<given-names><![CDATA[L. V.]]></given-names>
</name>
<name>
<surname><![CDATA[Higgins]]></surname>
<given-names><![CDATA[J. P.]]></given-names>
</name>
<name>
<surname><![CDATA[Rothstein]]></surname>
<given-names><![CDATA[H. R]]></given-names>
</name>
</person-group>
<source><![CDATA[Introduction to meta-analysis]]></source>
<year>2011</year>
<publisher-loc><![CDATA[EE.UU ]]></publisher-loc>
<publisher-name><![CDATA[John Wiley &amp; Sons]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B10">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Bougouin]]></surname>
<given-names><![CDATA[A. Appuhamy]]></given-names>
</name>
<name>
<surname><![CDATA[J. Kebreab]]></surname>
<given-names><![CDATA[E. Dijkstra]]></given-names>
</name>
<name>
<surname><![CDATA[J. Kwakkel]]></surname>
<given-names><![CDATA[R. P.]]></given-names>
</name>
<name>
<surname><![CDATA[France]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effects of phytase supplementation on phosphorus retention in broilers and layers: A meta-analysis]]></article-title>
<source><![CDATA[Poultry science]]></source>
<year>2014</year>
<volume>93</volume>
<numero>8</numero>
<issue>8</issue>
<page-range>1981-92</page-range></nlm-citation>
</ref>
<ref id="B11">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Calvo]]></surname>
<given-names><![CDATA[L]]></given-names>
</name>
<name>
<surname><![CDATA[Toldrá]]></surname>
<given-names><![CDATA[F]]></given-names>
</name>
<name>
<surname><![CDATA[Rodríguez]]></surname>
<given-names><![CDATA[A. I]]></given-names>
</name>
<name>
<surname><![CDATA[López-Bote]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
<name>
<surname><![CDATA[Rey]]></surname>
<given-names><![CDATA[A. I]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effect of dietary selenium source (organic vs. mineral) and muscle pH on meat quality characteristics of pigs]]></article-title>
<source><![CDATA[Food science &amp; nutrition]]></source>
<year>2017</year>
<volume>5</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>94-102</page-range></nlm-citation>
</ref>
<ref id="B12">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Cao]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Guo]]></surname>
<given-names><![CDATA[F]]></given-names>
</name>
<name>
<surname><![CDATA[Zhang]]></surname>
<given-names><![CDATA[L]]></given-names>
</name>
<name>
<surname><![CDATA[Dong]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Gong]]></surname>
<given-names><![CDATA[L]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effects of dietarySelenomethionine supplementation on growth performance, antioxidantstatus, plasma selenium concentration, and immune function inweaning pigs]]></article-title>
<source><![CDATA[Journal of animal science and Biotechnology]]></source>
<year>2015</year>
<volume>6</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>46-53</page-range></nlm-citation>
</ref>
<ref id="B13">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Catalá-López]]></surname>
<given-names><![CDATA[F.]]></given-names>
</name>
<name>
<surname><![CDATA[Tobías]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Metaanálisis en ensayos clínicos aleatorizados, heterogeneidad e intervalos de predicción]]></article-title>
<source><![CDATA[Med Clin (Barc)]]></source>
<year>2014</year>
<volume>142</volume>
<numero>6</numero>
<issue>6</issue>
<page-range>270-4</page-range></nlm-citation>
</ref>
<ref id="B14">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Chen]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Han]]></surname>
<given-names><![CDATA[J. H]]></given-names>
</name>
<name>
<surname><![CDATA[Guan]]></surname>
<given-names><![CDATA[W. T]]></given-names>
</name>
<name>
<surname><![CDATA[Chen]]></surname>
<given-names><![CDATA[F]]></given-names>
</name>
<name>
<surname><![CDATA[Wang]]></surname>
<given-names><![CDATA[C. X]]></given-names>
</name>
<name>
<surname><![CDATA[Zhang]]></surname>
<given-names><![CDATA[Y. Z.]]></given-names>
</name>
<name>
<surname><![CDATA[Lin]]></surname>
<given-names><![CDATA[G]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Selenium and vitamin E in sow diets: I. Effect on antioxidant status and reproductive performance in multiparous sows]]></article-title>
<source><![CDATA[Animal Feed Science and Technology]]></source>
<year>2016</year>
<volume>221</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>111-23</page-range></nlm-citation>
</ref>
<ref id="B15">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Chen]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Han]]></surname>
<given-names><![CDATA[J. H]]></given-names>
</name>
<name>
<surname><![CDATA[Guan]]></surname>
<given-names><![CDATA[W. T]]></given-names>
</name>
<name>
<surname><![CDATA[Chen]]></surname>
<given-names><![CDATA[F]]></given-names>
</name>
<name>
<surname><![CDATA[Wang]]></surname>
<given-names><![CDATA[C. X]]></given-names>
</name>
<name>
<surname><![CDATA[Zhang]]></surname>
<given-names><![CDATA[Y. Z.]]></given-names>
</name>
<name>
<surname><![CDATA[Lin]]></surname>
<given-names><![CDATA[G]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Selenium and vitamin E in sow diets: II. Effect on selenium status and antioxidant status of the progeny]]></article-title>
<source><![CDATA[Animal Feed Science and Technology]]></source>
<year>2016</year>
<volume>221</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>101-10</page-range></nlm-citation>
</ref>
<ref id="B16">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Chew]]></surname>
<given-names><![CDATA[B. P]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Importance of antioxidant vitamins in immunity and health in animals]]></article-title>
<source><![CDATA[Animal Feed Science and Technology]]></source>
<year>1996</year>
<volume>59</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>103-14</page-range></nlm-citation>
</ref>
<ref id="B17">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Chiba]]></surname>
<given-names><![CDATA[L. I]]></given-names>
</name>
</person-group>
<source><![CDATA[Sustainable swine nutrition. (First edition ed.)]]></source>
<year>2013</year>
<publisher-loc><![CDATA[Ames, Iowa, USA ]]></publisher-loc>
<publisher-name><![CDATA[John Wiley &amp; Sons]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B18">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Collins]]></surname>
<given-names><![CDATA[J. F]]></given-names>
</name>
</person-group>
<source><![CDATA[Molecular, Genetic, and Nutritional Aspects of Major and Trace Minerals]]></source>
<year>2016</year>
<publisher-name><![CDATA[Academic Press]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B19">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Dalgaard]]></surname>
<given-names><![CDATA[T. S. Briens]]></given-names>
</name>
<name>
<surname><![CDATA[M. Engberg]]></surname>
<given-names><![CDATA[R. M.]]></given-names>
</name>
<name>
<surname><![CDATA[Lauridsen]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The influence of selenium and selenoproteins on immune responses of poultry and pigs]]></article-title>
<source><![CDATA[Animal Feed Science and Technology]]></source>
<year>2018</year>
<volume>238</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>73-83</page-range></nlm-citation>
</ref>
<ref id="B20">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Duntas]]></surname>
<given-names><![CDATA[L. H.]]></given-names>
</name>
<name>
<surname><![CDATA[Benvenga]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Selenium: an element for life]]></article-title>
<source><![CDATA[Endocrine]]></source>
<year>2015</year>
<volume>48</volume>
<numero>3</numero>
<issue>3</issue>
<page-range>756-75</page-range></nlm-citation>
</ref>
<ref id="B21">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Egger]]></surname>
<given-names><![CDATA[M. Smith]]></given-names>
</name>
<name>
<surname><![CDATA[G. D. Schneider]]></surname>
<given-names><![CDATA[M.]]></given-names>
</name>
<name>
<surname><![CDATA[Minder]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Bias in meta-analysis detected by a simple, graphical test]]></article-title>
<source><![CDATA[Bmj]]></source>
<year>1997</year>
<volume>315</volume>
<numero>7109</numero>
<issue>7109</issue>
<page-range>629-34</page-range></nlm-citation>
</ref>
<ref id="B22">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Falk]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<name>
<surname><![CDATA[Bernhoft]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[Framstad]]></surname>
<given-names><![CDATA[T]]></given-names>
</name>
<name>
<surname><![CDATA[Salbu]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Wisløff]]></surname>
<given-names><![CDATA[H]]></given-names>
</name>
<name>
<surname><![CDATA[Kortner]]></surname>
<given-names><![CDATA[T. M]]></given-names>
</name>
<name>
<surname><![CDATA[Oropeza-Moe]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effects of dietary sodium selenite and organic selenium sources on immune and inflammatory responses and selenium deposition in growing pigs]]></article-title>
<source><![CDATA[Journal of Trace Elements in Medicine and Biology]]></source>
<year>2018</year>
<volume>50</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>527-36</page-range></nlm-citation>
</ref>
<ref id="B23">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Halliwell]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Free radicals and antioxidants: a personal view]]></article-title>
<source><![CDATA[Nutrition reviews]]></source>
<year>1994</year>
<volume>52</volume>
<numero>8</numero>
<issue>8</issue>
<page-range>253-65</page-range></nlm-citation>
</ref>
<ref id="B24">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Higgins]]></surname>
<given-names><![CDATA[J. P.]]></given-names>
</name>
<name>
<surname><![CDATA[Thompson]]></surname>
<given-names><![CDATA[S. G]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Quantifying heterogeneity in a meta&#8208;analysis]]></article-title>
<source><![CDATA[Statistics in medicine]]></source>
<year>2002</year>
<volume>21</volume>
<numero>11</numero>
<issue>11</issue>
<page-range>1539-58</page-range></nlm-citation>
</ref>
<ref id="B25">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Huang]]></surname>
<given-names><![CDATA[Z]]></given-names>
</name>
<name>
<surname><![CDATA[Rose]]></surname>
<given-names><![CDATA[A. H]]></given-names>
</name>
<name>
<surname><![CDATA[Hoffmann]]></surname>
<given-names><![CDATA[P. R]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[The role of selenium in inflammation and immunity: from molecular mechanisms to therapeutic opportunities]]></article-title>
<source><![CDATA[Antioxidants &amp; redox signaling]]></source>
<year>2012</year>
<volume>16</volume>
<numero>7</numero>
<issue>7</issue>
<page-range>705-43</page-range></nlm-citation>
</ref>
<ref id="B26">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Hung]]></surname>
<given-names><![CDATA[Y. T. Hanson]]></given-names>
</name>
<name>
<surname><![CDATA[A. R. Shurson]]></surname>
<given-names><![CDATA[G. C.]]></given-names>
</name>
<name>
<surname><![CDATA[Urriola]]></surname>
<given-names><![CDATA[P. E]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Peroxidized lipids reduce growth performance of poultry and swine: a meta-analysis]]></article-title>
<source><![CDATA[Animal Feed Science and Technology]]></source>
<year>2017</year>
<volume>231</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>47-58</page-range></nlm-citation>
</ref>
<ref id="B27">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ighodaro]]></surname>
<given-names><![CDATA[O. M.]]></given-names>
</name>
<name>
<surname><![CDATA[Akinloye]]></surname>
<given-names><![CDATA[O. A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[First line defence antioxidants-superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX): Their fundamental role in the entire antioxidant defence grid]]></article-title>
<source><![CDATA[Alexandria Journal of Medicine]]></source>
<year>2018</year>
<volume>54</volume>
<numero>4</numero>
<issue>4</issue>
<page-range>287-93</page-range></nlm-citation>
</ref>
<ref id="B28">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Jenkins]]></surname>
<given-names><![CDATA[K. J.]]></given-names>
</name>
<name>
<surname><![CDATA[Winter]]></surname>
<given-names><![CDATA[K. A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effects of selenium supplementation of naturally high selenium swine rations on tissue levels of the element]]></article-title>
<source><![CDATA[CanadianJournal of animal science]]></source>
<year>1973</year>
<volume>53</volume>
<numero>3</numero>
<issue>3</issue>
<page-range>561-7</page-range></nlm-citation>
</ref>
<ref id="B29">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Jiang]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Tang]]></surname>
<given-names><![CDATA[X]]></given-names>
</name>
<name>
<surname><![CDATA[Xue]]></surname>
<given-names><![CDATA[Y]]></given-names>
</name>
<name>
<surname><![CDATA[Lin]]></surname>
<given-names><![CDATA[G]]></given-names>
</name>
<name>
<surname><![CDATA[Xiong]]></surname>
<given-names><![CDATA[Y. L]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Dietary linseed oil supplemented with organic selenium improved the fatty acid nutritional profile, muscular selenium deposition, water retention, and tenderness of fresh pork]]></article-title>
<source><![CDATA[Meat science]]></source>
<year>2017</year>
<volume>131</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>99-106</page-range></nlm-citation>
</ref>
<ref id="B30">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Kiefer]]></surname>
<given-names><![CDATA[C.]]></given-names>
</name>
<name>
<surname><![CDATA[Sanches]]></surname>
<given-names><![CDATA[J. F]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Metanálise dos níveis de ractopamina em dietas para suínos em terminação]]></article-title>
<source><![CDATA[Revista Brasileira de Zootecnia]]></source>
<year>2009</year>
<volume>38</volume>
<numero>6</numero>
<issue>6</issue>
<page-range>1037-44</page-range></nlm-citation>
</ref>
<ref id="B31">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Labunskyy]]></surname>
<given-names><![CDATA[V. M]]></given-names>
</name>
<name>
<surname><![CDATA[Hatfield]]></surname>
<given-names><![CDATA[D. L]]></given-names>
</name>
<name>
<surname><![CDATA[Gladyshev]]></surname>
<given-names><![CDATA[V. N]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Selenoproteins: molecular pathways and physiological roles]]></article-title>
<source><![CDATA[Physiological reviews]]></source>
<year>2014</year>
<volume>94</volume>
<numero>3</numero>
<issue>3</issue>
<page-range>739-77</page-range></nlm-citation>
</ref>
<ref id="B32">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Lawrence]]></surname>
<given-names><![CDATA[R. A]]></given-names>
</name>
<name>
<surname><![CDATA[Burk]]></surname>
<given-names><![CDATA[R. F]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Glutathione peroxidase activity in selenium-deficient rat liver]]></article-title>
<source><![CDATA[Biochemical and biophysical research communications]]></source>
<year>1976</year>
<volume>71</volume>
<numero>4</numero>
<issue>4</issue>
<page-range>952-8</page-range></nlm-citation>
</ref>
<ref id="B33">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Létourneau-Montminy]]></surname>
<given-names><![CDATA[M. P. Jondreville]]></given-names>
</name>
<name>
<surname><![CDATA[C. Sauvant]]></surname>
<given-names><![CDATA[D.]]></given-names>
</name>
<name>
<surname><![CDATA[Narcy]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Meta-analysis of phosphorus utilization by growing pigs: effect of dietary phosphorus, calcium and exogenous phytase]]></article-title>
<source><![CDATA[Animal]]></source>
<year>2012</year>
<volume>6</volume>
<numero>10</numero>
<issue>10</issue>
<page-range>1590-600</page-range></nlm-citation>
</ref>
<ref id="B34">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Lisiak]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[Janiszewski]]></surname>
<given-names><![CDATA[P]]></given-names>
</name>
<name>
<surname><![CDATA[Blicharski]]></surname>
<given-names><![CDATA[T]]></given-names>
</name>
<name>
<surname><![CDATA[Borzuta]]></surname>
<given-names><![CDATA[K]]></given-names>
</name>
<name>
<surname><![CDATA[Grze&#347;kowiak]]></surname>
<given-names><![CDATA[E]]></given-names>
</name>
<name>
<surname><![CDATA[Lisiak]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Hammermeister]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effect of selenium supplementation in pig feed on slaughter value and physicochemical and sensory characteristics of meat]]></article-title>
<source><![CDATA[Annals of Animal Science]]></source>
<year>2014</year>
<volume>14</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>213-22</page-range></nlm-citation>
</ref>
<ref id="B35">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Lubos]]></surname>
<given-names><![CDATA[E]]></given-names>
</name>
<name>
<surname><![CDATA[Loscalzo]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Handy]]></surname>
<given-names><![CDATA[D. E]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Glutathione peroxidase-1 in health and disease: from molecular mechanisms to therapeutic opportunities]]></article-title>
<source><![CDATA[Antioxidants &amp; redox signaling]]></source>
<year>2011</year>
<volume>15</volume>
<numero>7</numero>
<issue>7</issue>
<page-range>1957-97</page-range></nlm-citation>
</ref>
<ref id="B36">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Ma]]></surname>
<given-names><![CDATA[Y. L]]></given-names>
</name>
<name>
<surname><![CDATA[Lindemann]]></surname>
<given-names><![CDATA[M. D]]></given-names>
</name>
<name>
<surname><![CDATA[Pierce]]></surname>
<given-names><![CDATA[J. L]]></given-names>
</name>
<name>
<surname><![CDATA[Unrine]]></surname>
<given-names><![CDATA[J. M]]></given-names>
</name>
<name>
<surname><![CDATA[Cromwell]]></surname>
<given-names><![CDATA[G. L]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effect of inorganic or organic selenium supplementation on reproductive performance and tissue trace mineral concentrations in gravid first-parity gilts, fetuses, and nursing piglets]]></article-title>
<source><![CDATA[Journal of animal science]]></source>
<year>2014</year>
<volume>92</volume>
<numero>12</numero>
<issue>12</issue>
<page-range>5540-50</page-range></nlm-citation>
</ref>
<ref id="B37">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Mahan]]></surname>
<given-names><![CDATA[D. C]]></given-names>
</name>
<name>
<surname><![CDATA[Parrett]]></surname>
<given-names><![CDATA[N. A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Evaluating the efficacy of selenium-enriched yeast and sodium selenite on tissue selenium retention and serum glutathione peroxidase activity in grower and finisher swine]]></article-title>
<source><![CDATA[Journal of animal science]]></source>
<year>1996</year>
<volume>74</volume>
<numero>12</numero>
<issue>12</issue>
<page-range>2967-74</page-range></nlm-citation>
</ref>
<ref id="B38">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Mahan]]></surname>
<given-names><![CDATA[D. C]]></given-names>
</name>
<name>
<surname><![CDATA[Peters]]></surname>
<given-names><![CDATA[J. C]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Long-term effects of dietary organic and inorganic selenium sources and levels on reproducing sows and their progeny]]></article-title>
<source><![CDATA[Journal of animal science]]></source>
<year>2004</year>
<volume>82</volume>
<numero>5</numero>
<issue>5</issue>
<page-range>1343-58</page-range></nlm-citation>
</ref>
<ref id="B39">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Mahan]]></surname>
<given-names><![CDATA[D. C]]></given-names>
</name>
<name>
<surname><![CDATA[Azain]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<name>
<surname><![CDATA[Crenshaw]]></surname>
<given-names><![CDATA[T. D]]></given-names>
</name>
<name>
<surname><![CDATA[Cromwell]]></surname>
<given-names><![CDATA[G. L]]></given-names>
</name>
<name>
<surname><![CDATA[Dove]]></surname>
<given-names><![CDATA[C. R]]></given-names>
</name>
<name>
<surname><![CDATA[Kim]]></surname>
<given-names><![CDATA[S. W]]></given-names>
</name>
<name>
<surname><![CDATA[van Heugten]]></surname>
<given-names><![CDATA[E]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Supplementation of organic and inorganic selenium to diets using grains grown in various regions of the United States with differing natural Se concentrations and fed to grower-finisher swine]]></article-title>
<source><![CDATA[Journal of animal science]]></source>
<year>2014</year>
<volume>92</volume>
<numero>11</numero>
<issue>11</issue>
<page-range>4991-7</page-range></nlm-citation>
</ref>
<ref id="B40">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Mahan]]></surname>
<given-names><![CDATA[D. C]]></given-names>
</name>
<name>
<surname><![CDATA[Cline]]></surname>
<given-names><![CDATA[T. R]]></given-names>
</name>
<name>
<surname><![CDATA[Richert]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effects of dietary levels of selenium-enriched yeast and sodium selenite as selenium sources fed to growing-finishing pigs on performance, tissue selenium, serum glutathione peroxidase activity, carcass characteristics, and loin quality]]></article-title>
<source><![CDATA[Journal of animal science]]></source>
<year>1999</year>
<volume>77</volume>
<numero>8</numero>
<issue>8</issue>
<page-range>2172-9</page-range></nlm-citation>
</ref>
<ref id="B41">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Marin-Guzman]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Mahan]]></surname>
<given-names><![CDATA[D. C]]></given-names>
</name>
<name>
<surname><![CDATA[Chung]]></surname>
<given-names><![CDATA[Y. K]]></given-names>
</name>
<name>
<surname><![CDATA[Pate]]></surname>
<given-names><![CDATA[J. L]]></given-names>
</name>
<name>
<surname><![CDATA[Pope]]></surname>
<given-names><![CDATA[W. F]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effects of dietary selenium and vitamin E on boar performance and tissue responses, semen quality, and subsequent fertilization rates in mature gilts]]></article-title>
<source><![CDATA[Journal of animal science]]></source>
<year>1997</year>
<volume>75</volume>
<numero>11</numero>
<issue>11</issue>
<page-range>2994-3003</page-range></nlm-citation>
</ref>
<ref id="B42">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Markley]]></surname>
<given-names><![CDATA[R. L]]></given-names>
</name>
<name>
<surname><![CDATA[Williamson]]></surname>
<given-names><![CDATA[D. R]]></given-names>
</name>
<name>
<surname><![CDATA[Katkere]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Dewan]]></surname>
<given-names><![CDATA[K. K]]></given-names>
</name>
<name>
<surname><![CDATA[Shay]]></surname>
<given-names><![CDATA[A. E]]></given-names>
</name>
<name>
<surname><![CDATA[Sumner]]></surname>
<given-names><![CDATA[S. E]]></given-names>
</name>
<name>
<surname><![CDATA[Kirimanjeswara]]></surname>
<given-names><![CDATA[G. S]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Macrophage selenoproteins restrict intracellular replication of Francisella tularensis]]></article-title>
<source><![CDATA[The Journal of Immunology]]></source>
<year>2017</year>
<volume>198</volume>
<numero>1 Supplement</numero>
<issue>1 Supplement</issue>
<page-range>148-12</page-range></nlm-citation>
</ref>
<ref id="B43">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Martins]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
<name>
<surname><![CDATA[De Andrade]]></surname>
<given-names><![CDATA[A. F]]></given-names>
</name>
<name>
<surname><![CDATA[Zaffalon]]></surname>
<given-names><![CDATA[F. G]]></given-names>
</name>
<name>
<surname><![CDATA[Parazzi]]></surname>
<given-names><![CDATA[L. J]]></given-names>
</name>
<name>
<surname><![CDATA[Bressan]]></surname>
<given-names><![CDATA[F. F]]></given-names>
</name>
<name>
<surname><![CDATA[Pugine]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
<name>
<surname><![CDATA[Moretti]]></surname>
<given-names><![CDATA[A. S]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Organic selenium increases PHGPx, but does not affect quality sperm in raw boar semen]]></article-title>
<source><![CDATA[Livestock Science]]></source>
<year>2014</year>
<volume>164</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>175-8</page-range></nlm-citation>
</ref>
<ref id="B44">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[McKenzie]]></surname>
<given-names><![CDATA[R. C]]></given-names>
</name>
<name>
<surname><![CDATA[Rafferty]]></surname>
<given-names><![CDATA[T. S]]></given-names>
</name>
<name>
<surname><![CDATA[Beckett]]></surname>
<given-names><![CDATA[G. J]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Selenium: an essential element for immune function]]></article-title>
<source><![CDATA[Immunology today]]></source>
<year>1998</year>
<volume>19</volume>
<numero>8</numero>
<issue>8</issue>
<page-range>342-5</page-range></nlm-citation>
</ref>
<ref id="B45">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Metzler-Zebeli]]></surname>
<given-names><![CDATA[B. U]]></given-names>
</name>
<name>
<surname><![CDATA[Trevisi]]></surname>
<given-names><![CDATA[P]]></given-names>
</name>
<name>
<surname><![CDATA[Prates]]></surname>
<given-names><![CDATA[J. A]]></given-names>
</name>
<name>
<surname><![CDATA[Tanghe]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
<name>
<surname><![CDATA[Bosi]]></surname>
<given-names><![CDATA[P]]></given-names>
</name>
<name>
<surname><![CDATA[Canibe]]></surname>
<given-names><![CDATA[N]]></given-names>
</name>
<name>
<surname><![CDATA[Zebeli]]></surname>
<given-names><![CDATA[Q]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Assessing the effect of dietary inulin supplementation on gastrointestinal fermentation, digestibility and growth in pigs: A meta-analysis]]></article-title>
<source><![CDATA[Animal Feed Science and Technology]]></source>
<year>2017</year>
<volume>233</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>120-32</page-range></nlm-citation>
</ref>
<ref id="B46">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Moher]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[Shamseer]]></surname>
<given-names><![CDATA[L]]></given-names>
</name>
<name>
<surname><![CDATA[Clarke]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<name>
<surname><![CDATA[Ghersi]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[Liberati]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[Petticrew]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<name>
<surname><![CDATA[Stewart]]></surname>
<given-names><![CDATA[L. A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015 statement]]></article-title>
<source><![CDATA[Systematic reviews]]></source>
<year>2015</year>
<volume>4</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>1-8</page-range></nlm-citation>
</ref>
<ref id="B47">
<nlm-citation citation-type="book">
<collab>National Research Council</collab>
<source><![CDATA[Nutrient requirements of swine (Eleventh Revised Edition ed.)]]></source>
<year>2012</year>
<publisher-loc><![CDATA[Washigton, D.C. ]]></publisher-loc>
<publisher-name><![CDATA[National Academies Press]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B48">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Oropeza-Moe]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<name>
<surname><![CDATA[Wisløff]]></surname>
<given-names><![CDATA[H]]></given-names>
</name>
<name>
<surname><![CDATA[Bernhoft]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Selenium deficiency associated porcine and human cardiomyopathies]]></article-title>
<source><![CDATA[Journal of Trace Elements in Medicine and Biology]]></source>
<year>2015</year>
<volume>31</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>148-56</page-range></nlm-citation>
</ref>
<ref id="B49">
<nlm-citation citation-type="book">
<collab>PIC</collab>
<source><![CDATA[Manual de especificación de nutrientes]]></source>
<year>2016</year>
<publisher-name><![CDATA[PIC]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B50">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Remus]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[Peres]]></surname>
<given-names><![CDATA[F. M]]></given-names>
</name>
<name>
<surname><![CDATA[Hauschild]]></surname>
<given-names><![CDATA[L]]></given-names>
</name>
<name>
<surname><![CDATA[Andretta]]></surname>
<given-names><![CDATA[I]]></given-names>
</name>
<name>
<surname><![CDATA[Kipper]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<name>
<surname><![CDATA[de Paula]]></surname>
<given-names><![CDATA[G. J]]></given-names>
</name>
<name>
<surname><![CDATA[Pomar]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Exploratory study on the utilization of different dietary methionine sources and methionine to lysine ratio for growing-finishing pigs]]></article-title>
<source><![CDATA[Livestock Science]]></source>
<year>2015</year>
<volume>181</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>96-102</page-range></nlm-citation>
</ref>
<ref id="B51">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Roman]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<name>
<surname><![CDATA[Jitaru]]></surname>
<given-names><![CDATA[P]]></given-names>
</name>
<name>
<surname><![CDATA[Barbante]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Selenium biochemistry and its role for human health]]></article-title>
<source><![CDATA[Metallomics]]></source>
<year>2014</year>
<volume>6</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>25-54</page-range></nlm-citation>
</ref>
<ref id="B52">
<nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Rostagno]]></surname>
<given-names><![CDATA[H. S]]></given-names>
</name>
<name>
<surname><![CDATA[Texeira Albino]]></surname>
<given-names><![CDATA[L. F]]></given-names>
</name>
<name>
<surname><![CDATA[Hannas]]></surname>
<given-names><![CDATA[M. I]]></given-names>
</name>
<name>
<surname><![CDATA[Lopes Donzele]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Sakomura]]></surname>
<given-names><![CDATA[N]]></given-names>
</name>
<name>
<surname><![CDATA[Perazzo]]></surname>
<given-names><![CDATA[F. G]]></given-names>
</name>
<name>
<surname><![CDATA[de Oliveira Brito]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
</person-group>
<source><![CDATA[Tablas Brasileñas para Aves y Cerdos. (Cuarta edición ed.)]]></source>
<year>2017</year>
<publisher-loc><![CDATA[Viçosa ]]></publisher-loc>
<publisher-name><![CDATA[Universidad Federal de Viçosa]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B53">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Sales]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[A meta-analysis of the effects of dietary betaine supplementation on finishing performance and carcass characteristics of pigs]]></article-title>
<source><![CDATA[Animal Feed Science and Technology]]></source>
<year>2011</year>
<volume>165</volume>
<numero>1-2</numero>
<issue>1-2</issue>
<page-range>68-78</page-range></nlm-citation>
</ref>
<ref id="B54">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Sauvant]]></surname>
<given-names><![CDATA[D. Schmidely]]></given-names>
</name>
<name>
<surname><![CDATA[P. Daudin]]></surname>
<given-names><![CDATA[J. J.]]></given-names>
</name>
<name>
<surname><![CDATA[St-Pierre]]></surname>
<given-names><![CDATA[N. R]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Meta-analyses of experimental data in animal nutrition]]></article-title>
<source><![CDATA[Animal]]></source>
<year>2008</year>
<volume>2</volume>
<numero>8</numero>
<issue>8</issue>
<page-range>1203-14</page-range></nlm-citation>
</ref>
<ref id="B55">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Seyedali]]></surname>
<given-names><![CDATA[A.]]></given-names>
</name>
<name>
<surname><![CDATA[Berry]]></surname>
<given-names><![CDATA[M. J]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Nonsense-mediated decay factors are involved in the regulation of selenoprotein mRNA levels during selenium deficiency]]></article-title>
<source><![CDATA[Rna]]></source>
<year>2014</year>
<volume>20</volume>
<numero>8</numero>
<issue>8</issue>
<page-range>1248-56</page-range></nlm-citation>
</ref>
<ref id="B56">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Surai]]></surname>
<given-names><![CDATA[P. F.]]></given-names>
</name>
<name>
<surname><![CDATA[Fisinin]]></surname>
<given-names><![CDATA[V. I]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Selenium in poultry breeder nutrition: An update]]></article-title>
<source><![CDATA[Animal Feed Science and Technology]]></source>
<year>2014</year>
<volume>191</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>1-15</page-range></nlm-citation>
</ref>
<ref id="B57">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Surai]]></surname>
<given-names><![CDATA[P. F.]]></given-names>
</name>
<name>
<surname><![CDATA[Fisinin]]></surname>
<given-names><![CDATA[V. I]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Selenium in Pig Nutrition and reproduction: Boars and semen quality-A Review]]></article-title>
<source><![CDATA[Asian-Australasian Journal of animal science s]]></source>
<year>2015</year>
<volume>28</volume>
<numero>5</numero>
<issue>5</issue>
<page-range>730-46</page-range></nlm-citation>
</ref>
<ref id="B58">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Surai]]></surname>
<given-names><![CDATA[P. F.]]></given-names>
</name>
<name>
<surname><![CDATA[Fisinin]]></surname>
<given-names><![CDATA[V. I]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Selenium in sow nutrition]]></article-title>
<source><![CDATA[Animal Feed Science and Technology]]></source>
<year>2016</year>
<volume>211</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>18-30</page-range></nlm-citation>
</ref>
<ref id="B59">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Torres-Pitarch]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[Hermans]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[Manzanilla]]></surname>
<given-names><![CDATA[E. G]]></given-names>
</name>
<name>
<surname><![CDATA[Bindelle]]></surname>
<given-names><![CDATA[J]]></given-names>
</name>
<name>
<surname><![CDATA[Everaert]]></surname>
<given-names><![CDATA[N]]></given-names>
</name>
<name>
<surname><![CDATA[Beckers]]></surname>
<given-names><![CDATA[Y]]></given-names>
</name>
<name>
<surname><![CDATA[Lawlor]]></surname>
<given-names><![CDATA[P. G]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effect of feed enzymes on digestibility and growth in weaned pigs: A systematic review and meta-analysis]]></article-title>
<source><![CDATA[Animal Feed Science and Technology]]></source>
<year>2017</year>
<volume>233</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>145-59</page-range></nlm-citation>
</ref>
<ref id="B60">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Torres-Pitarch]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[Manzanilla]]></surname>
<given-names><![CDATA[E. G]]></given-names>
</name>
<name>
<surname><![CDATA[Gardiner]]></surname>
<given-names><![CDATA[G. E]]></given-names>
</name>
<name>
<surname><![CDATA[O&#8217;Doherty]]></surname>
<given-names><![CDATA[J. V]]></given-names>
</name>
<name>
<surname><![CDATA[Lawlor]]></surname>
<given-names><![CDATA[P. G]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Systematic review and meta-analysis of the effect of feed enzymes on growth and nutrient digestibility in grow-finisher pigs: Effect of enzyme type and cereal source]]></article-title>
<source><![CDATA[Animal Feed Science and Technology]]></source>
<year>2019</year>
<volume>251</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>153-65</page-range></nlm-citation>
</ref>
<ref id="B61">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Urso]]></surname>
<given-names><![CDATA[U. R]]></given-names>
</name>
<name>
<surname><![CDATA[Dahlke]]></surname>
<given-names><![CDATA[F]]></given-names>
</name>
<name>
<surname><![CDATA[Maiorka]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[Bueno]]></surname>
<given-names><![CDATA[I. J]]></given-names>
</name>
<name>
<surname><![CDATA[Schneider]]></surname>
<given-names><![CDATA[A. F]]></given-names>
</name>
<name>
<surname><![CDATA[Surek]]></surname>
<given-names><![CDATA[D]]></given-names>
</name>
<name>
<surname><![CDATA[Rocha]]></surname>
<given-names><![CDATA[C]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Vitamin E and selenium in broiler breeder diets: Effect on live performance, hatching process, and chick quality]]></article-title>
<source><![CDATA[Poultry science]]></source>
<year>2015</year>
<volume>94</volume>
<numero>5</numero>
<issue>5</issue>
<page-range>976-83</page-range></nlm-citation>
</ref>
<ref id="B62">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Wang]]></surname>
<given-names><![CDATA[L]]></given-names>
</name>
<name>
<surname><![CDATA[Xu]]></surname>
<given-names><![CDATA[X]]></given-names>
</name>
<name>
<surname><![CDATA[Su]]></surname>
<given-names><![CDATA[G]]></given-names>
</name>
<name>
<surname><![CDATA[Shi]]></surname>
<given-names><![CDATA[B]]></given-names>
</name>
<name>
<surname><![CDATA[Shan]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[High concentration of vitamin E supplementation in sow diet during the last week of gestation and lactation affects the immunological variables and antioxidative parameters in piglets]]></article-title>
<source><![CDATA[Journal of Dairy Research]]></source>
<year>2017</year>
<volume>84</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>8-13</page-range></nlm-citation>
</ref>
<ref id="B63">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Young]]></surname>
<given-names><![CDATA[L. G]]></given-names>
</name>
<name>
<surname><![CDATA[Castell]]></surname>
<given-names><![CDATA[A. G]]></given-names>
</name>
<name>
<surname><![CDATA[Edmeades]]></surname>
<given-names><![CDATA[D. E]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Influence of dietary levels of selenium on tissue selenium of growing pigs in Canada]]></article-title>
<source><![CDATA[Journal of animal science]]></source>
<year>1977</year>
<volume>44</volume>
<numero>4</numero>
<issue>4</issue>
<page-range>590-4</page-range></nlm-citation>
</ref>
<ref id="B64">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Zeng]]></surname>
<given-names><![CDATA[Z. K]]></given-names>
</name>
<name>
<surname><![CDATA[Shurson]]></surname>
<given-names><![CDATA[G. C]]></given-names>
</name>
<name>
<surname><![CDATA[Urriola]]></surname>
<given-names><![CDATA[P. E]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Prediction of the concentration of standardized ileal digestible amino acids and safety margins among sources of distillers dried grains with solubles for growing pigs: A meta-analysis approach]]></article-title>
<source><![CDATA[Animal Feed Science and Technology]]></source>
<year>2017</year>
<volume>231</volume>
<numero>1</numero>
<issue>1</issue>
<page-range>150-9</page-range></nlm-citation>
</ref>
<ref id="B65">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Zhan]]></surname>
<given-names><![CDATA[X]]></given-names>
</name>
<name>
<surname><![CDATA[Wang]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<name>
<surname><![CDATA[Zhao]]></surname>
<given-names><![CDATA[R]]></given-names>
</name>
<name>
<surname><![CDATA[Li]]></surname>
<given-names><![CDATA[W]]></given-names>
</name>
<name>
<surname><![CDATA[Xu]]></surname>
<given-names><![CDATA[Z]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Effects of different selenium source on selenium distribution, loin quality and antioxidant status in finishing pigs]]></article-title>
<source><![CDATA[Animal Feed Science and Technology]]></source>
<year>2007</year>
<volume>132</volume>
<numero>3-4</numero>
<issue>3-4</issue>
<page-range>202-11</page-range></nlm-citation>
</ref>
<ref id="B66">
<nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Zoidis]]></surname>
<given-names><![CDATA[E]]></given-names>
</name>
<name>
<surname><![CDATA[Demiris]]></surname>
<given-names><![CDATA[N]]></given-names>
</name>
<name>
<surname><![CDATA[Kominakis]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
<name>
<surname><![CDATA[Pappas]]></surname>
<given-names><![CDATA[A. C]]></given-names>
</name>
</person-group>
<article-title xml:lang=""><![CDATA[Meta-analysis of selenium accumulation and expression of antioxidant enzymes in chicken tissues]]></article-title>
<source><![CDATA[animal]]></source>
<year>2014</year>
<volume>8</volume>
<numero>4</numero>
<issue>4</issue>
<page-range>542-54</page-range></nlm-citation>
</ref>
</ref-list>
</back>
</article>
