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	<front>
		<journal-meta>
			<journal-id journal-id-type="publisher-id">av</journal-id>
			<journal-title-group>
				<journal-title>Abanico veterinario</journal-title>
				<abbrev-journal-title abbrev-type="publisher">Abanico vet</abbrev-journal-title>
			</journal-title-group>
			<issn pub-type="ppub">2007-428X</issn>
			<issn pub-type="epub">2448-6132</issn>
			<publisher>
				<publisher-name>Sergio Martínez González</publisher-name>
			</publisher>
		</journal-meta>
		<article-meta>
			<article-id pub-id-type="doi">10.21929/abavet2019.919</article-id>
			<article-id pub-id-type="other">00122</article-id>
			<article-categories>
				<subj-group subj-group-type="heading">
					<subject>Artículo Original.</subject>
				</subj-group>
			</article-categories>
			<title-group>
				<article-title>Frecuencia de parásitos gastrointestinales en bovinos del sur de Sonora, México</article-title>
			</title-group>
			<contrib-group>
				<contrib contrib-type="author">
					<contrib-id contrib-id-type="orcid">0000-0002-8142-5021</contrib-id>
					<name>
						<surname>Munguía-Xóchihua</surname>
						<given-names>Javier</given-names>
					</name>
					<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
					<xref ref-type="corresp" rid="c1">*</xref>
				</contrib>
				<contrib contrib-type="author">
					<contrib-id contrib-id-type="orcid">0000-0001-7704-1503</contrib-id>
					<name>
						<surname>Leal-Franco</surname>
						<given-names>Ivette</given-names>
					</name>
					<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
				</contrib>
				<contrib contrib-type="author">
					<contrib-id contrib-id-type="orcid">0000-0003-2089-5078</contrib-id>
					<name>
						<surname>Muñoz-Cabrera</surname>
						<given-names>José</given-names>
					</name>
					<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
				</contrib>
				<contrib contrib-type="author">
					<contrib-id contrib-id-type="orcid">0000-0003-1155-8600</contrib-id>
					<name>
						<surname>Medina-Chu</surname>
						<given-names>Manuel</given-names>
					</name>
					<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
				</contrib>
				<contrib contrib-type="author">
					<contrib-id contrib-id-type="orcid">0000-0001-8898-7177</contrib-id>
					<name>
						<surname>Reyna-Granados</surname>
						<given-names>Javier</given-names>
					</name>
					<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
				</contrib>
				<contrib contrib-type="author">
					<contrib-id contrib-id-type="orcid">0000-0002-9530-4810</contrib-id>
					<name>
						<surname>López-Castro</surname>
						<given-names>Pedro</given-names>
					</name>
					<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
				</contrib>
				<aff id="aff1">
					<label>1</label>
					<institution content-type="original">Departamento de Ciencias Agronómicas y Veterinarias. Instituto Tecnológico de Sonora, 5 de febrero 818 sur. Colonia Centro CP 85000. Cd. Obregón, Sonora. México.</institution>
					<institution content-type="normalized">Instituto Tecnológico de Sonora</institution>
					<institution content-type="orgname">Instituto Tecnológico de Sonora</institution>
					<addr-line>
						<city>Cd. Obregón</city>
						<state>Sonora</state>
					</addr-line>
					<country country="MX">Mexico</country>
				</aff>
			</contrib-group>
			<author-notes>
				<corresp id="c1">*Autor responsable y de correspondencia: Munguía-Xóchihua <email>Javier.javier.munguia@itson.edu.mx</email>, <email>karypl05@gmail.com</email>
					<email>javier.reyna@itson.edu.mx</email>, <email>mcjose_54_muca@hotmail.com</email>, <email>alejandro_medina_chu@hotmail.com</email>, <email>pedro.alan@itson.edu.mx</email>
				</corresp>
			</author-notes>
			<pub-date date-type="pub" publication-format="electronic">
				<day>30</day>
				<month>05</month>
				<year>2020</year>
			</pub-date>
			<pub-date date-type="collection" publication-format="electronic">
				<season>Jan-Dec</season>
				<year>2019</year>
			</pub-date>
			<volume>9</volume>
			<elocation-id>e922</elocation-id>
			<history>
				<date date-type="received">
					<day>24</day>
					<month>02</month>
					<year>2019</year>
				</date>
				<date date-type="accepted">
					<day>28</day>
					<month>09</month>
					<year>2019</year>
				</date>
			</history>
			<permissions>
				<license license-type="open-access" xlink:href="https://creativecommons.org/licenses/by-nc/4.0/" xml:lang="es">
					<license-p>Este es un artículo publicado en acceso abierto bajo una licencia Creative Commons</license-p>
				</license>
			</permissions>
			<abstract>
				<title>RESUMEN</title>
				<p>Comúnmente los parásitos gastroentéricos son un problema sanitario en la ganadería extensiva y pueden ser un riesgo en la eficiencia productiva del ganado al sur de Sonora, México. Para determinar la frecuencia de los diferentes géneros parasitarios gastrointestinales en bovinos de la región sur de Sonora, se dividió un estudio en región <italic>Sierra alta</italic> (n= 218), <italic>Sierra baja</italic> (n=173), <italic>Valle1</italic> (n= 222) y <italic>Valle2</italic> (n= 50). Las heces fueron colectadas de bovinos adultos y becerros (5 a 6 meses de edad) de enero a marzo y diciembre de 2018; enero a febrero de 2019. Las muestras se analizaron mediante las técnicas flotación y MacMaster. La morfología fue determinada al obtener la etapa L3 mediante coprocultivo. Las <italic>Eimerias</italic> fueron identificadas previa esporulación. Un 83.03%, 56.0% y 17.56% fueron positivos a parásitos gastrointestinales en <italic>Sierra alta, Sierra baja y Valle1</italic> respectivamente. El <italic>Valle2</italic> fue negativo a nematodos, pero el 43% resulto positivos a <italic>Eimerias</italic>. Los bovinos en la zona de estudio mostraron una frecuencia de baja 17.56% a alta 83.03% a parásitos gastroentéricos con presencia de uno a ocho géneros de nematodos y de uno a siete de <italic>Eimeria</italic>.</p>
			</abstract>
			<kwd-group xml:lang="es">
				<title>Palabras clave:</title>
				<kwd>Ganado</kwd>
				<kwd>nematodos</kwd>
				<kwd>eimerias</kwd>
				<kwd>semiárido</kwd>
				<kwd>sierra</kwd>
			</kwd-group>
			<funding-group>
				<award-group award-type="contract">
					<funding-source>Programa de Fomento y Apoyo a la Investigación (PROFAPI)</funding-source>
					<award-id>PROFAPI_2018_0047</award-id>
					<award-id>PROFAPI_ 2019_0052</award-id>
				</award-group>
			</funding-group>
			<counts>
				<fig-count count="0"/>
				<table-count count="8"/>
				<equation-count count="0"/>
				<ref-count count="30"/>				
			</counts>
		</article-meta>
	</front>
	<body>
		<sec sec-type="intro">
			<title>INTRODUCCIÓN</title>
			<p>La producción de ganado bovino para carne en Sonora se desarrolla en más de 15 millones de hectáreas de agostaderos, se utiliza el 83% de la superficie estatal, con 1.5 millones de cabezas de ganado (<xref ref-type="bibr" rid="B5">Denogean <italic>et al</italic>., 2013</xref>). Para el ganadero las condiciones del clima y ecológicas son un elemento restrictivo para una adecuada producción, la cual depende del potencial de los forrajes para satisfacer las necesidades nutricionales (<xref ref-type="bibr" rid="B5">Denogean <italic>et al</italic>., 2013</xref>; <xref ref-type="bibr" rid="B19">Retes <italic>et al</italic>., 2013</xref>). El delicado equilibrio de nutrientes y salud de los bovinos está en riesgo constante al estar expuestos a infecciones por parásitos gastroentéricos (PGE), que disminuyen en forma importante el consumo de alimento, la conversión alimenticia y ganancia de peso, con morbilidad y mortalidad en animales jóvenes (<xref ref-type="bibr" rid="B25">Stromberg <italic>et al</italic>., 2012</xref>).</p>
			<p>En el abomaso se dañan las células secretorias que afectan la cantidad y calidad del ácido clorhídrico, lo cual modifica el valor pH hasta 6.5 y se disminuye la eficacia de la digestión y absorción de nutrientes; afecta el metabolismo mineral y proteico, en presentación subclínica y crónica los animales reducen su consumo de alimento entre 15 a 20 %, lo cual disminuye la ganancia de peso o hay pérdida de peso; por lo cual se aumentan las deficiencias nutricionales y se reduce la productividad del ganado (<xref ref-type="bibr" rid="B27">Torres, 2006</xref>; <xref ref-type="bibr" rid="B2">Biswajit <italic>et al</italic>., 2017</xref>; <xref ref-type="bibr" rid="B15">Oliviera <italic>et al</italic>., 2017</xref>). En algunos casos se puede observar anorexia aguda, anemia, toxemia, daño a los tejidos y muerte; por lo general en animales jóvenes en el crecimiento y en ocasiones en adultos (<xref ref-type="bibr" rid="B10">Johanssos, 2017</xref>).</p>
			<p>El potencial impacto económico de los parásitos en México se estimó y se obtuvo para los nematodos gastroentéricos US$ 445.10 y para coccidias (<italic>Eimeria</italic> spp.) US$23.78 millones, con base a la población nacional en 2013 de 32.4 millones de bovinos (<xref ref-type="bibr" rid="B21">Rodríguez <italic>et al</italic>., 2017</xref>). Por los efectos detrimentales en la producción y la salud, es importante disponer de información de la presencia de PGE en la región.</p>
			<p>El objetivo del presente trabajo de investigación fue determinar la frecuencia y los géneros de parásitos gastroentéricos en bovinos de cuatro sectores del sur de Sonora, México.</p>
		</sec>
		<sec sec-type="materials|methods">
			<title>MATERIAL Y MÉTODOS</title>
			<p>Localización geográfica. El estudio se realizó en un sector de la <italic>Sierra alta</italic> y en la <italic>Sierra baja</italic>, así como dos sectores del valle del sur de Sonora. En el sector <italic>Sierra alta</italic> se trabajó en el municipio de Yécora, el cual se localiza a 215 kilómetros al norte de Cd. Obregón, a 1540 metros de altitud; el clima que predomina es templado subhúmedo con lluvias en la mayor parte del año. En febrero y marzo, la temperatura alcanza los 24.0°C y el promedio anual es de 24.4°C, con precipitación promedio anual de 944 mm (SMN, 2018). En el sector <italic>Sierra baja</italic>, se trabajó en el municipio de Rosario, en el poblado de Tesopaco, localizado con altitud de 450 metros; presenta clima semiseco o semicálido, con temperatura promedio máxima de 29.2°C. y mínima de 14.2°C. Las lluvias predominan durante julio y agosto, con precipitación media anual de 610.1 mm (<xref ref-type="bibr" rid="B24">SMN, 2018</xref>).</p>
			<p>En la zona <italic>Valle 1</italic> y <italic>Valle 2</italic>, ubicados en el municipio de Cajeme, al sur del estado de Sonora, con altitud de 46 metros, donde predomina clima seco cálido extremoso, con precipitación media anual de 300 mm, el 73% de la precipitación se presenta de julio a septiembre, con temperatura promedio anual que fluctúa entre 24° C a 31° C; la máxima es de 48° C en verano y la mínima de 16° C en enero (<xref ref-type="bibr" rid="B24">SMN, 2018</xref>).</p>
			<p>Toma de muestras. En corrales de acopio del sector <italic>Sierra alta</italic> se muestrearon 218 becerros (140 machos y 78 hembras) y de <italic>Sierra baja</italic> a 173 becerros (130 machos y 43 hembras); todos eran pie de cría de bovinos, la mayoría criollo destetado o en inicio de destete, entre 5 y 10 meses de edad, criados en forma extensiva y a libre pastoreo. Las muestras de región <italic>Valle 1,</italic> fueron 222 muestras de 8 hatos de bovinos adultos productores de leche; de la región <italic>Valle 2,</italic> fueron 50 bovinos adultos en agostadero. La toma de muestras se realizó de enero a marzo y diciembre de 2018, y de enero a febrero de 2019, para realizar un estudio observacional y transversal (<xref ref-type="bibr" rid="B26">Thursfield, 2018</xref>). Se realizó un muestreo por conveniencia en los corrales de acopio y en los hatos, en donde se permitió la toma de muestras (<xref ref-type="bibr" rid="B23">Scheaffer <italic>et al</italic>., 2012</xref>).</p>
			<p>A las muestras de heces se realizaron la técnica cualitativa de flotación y cuantitativa de MacMaster, para obtener huevos por gramo de heces (HGH), ooquistes por gramo de heces (OGH); coprocultivo y Baerman (<xref ref-type="bibr" rid="B30">Yacob <italic>et al</italic>., 2009</xref>); en esta última las larvas (L3) presentes se identificaron con base en sus características morfológicas (<xref ref-type="bibr" rid="B17">Pinilla <italic>et al</italic>., 2018</xref>). Se realizó la técnica de esporulación para identificación de las Eimerias (<xref ref-type="bibr" rid="B14">Mitchell e<italic>t al</italic>., 2012</xref>). Por medio del programa Microsoft Excel 2016, se obtuvieron los resultados que se muestran en estadística descriptiva (<xref ref-type="bibr" rid="B29">Wayne, 2014</xref>).</p>
		</sec>
		<sec sec-type="results|discussion">
			<title>RESULTADOS Y DISCUSIÓN</title>
			<p>En la <italic>Sierra alta</italic> se encontraron: 83.03% (181/218) becerros positivos y 16.97% (37/218) negativos a parásitos gastroentéricos. El tipo de género para nematodos fue de 88.95% (161/181) positivos, cestodos 19.33% (35/181) y protozoarios 80.11% (145/181). El rango de MacMaster para cada género fue: nematodos 50-900 HGH, cestodos 50-6850 HGH, protozoarios 50-5050 OGH.</p>
			<p>Los géneros más frecuentes fueron: <italic>Haemonchus</italic> spp. 79.5%, <italic>Oesophagostomum</italic> spp. 40.37% y <italic>Trichostrongylus</italic> spp. 34.78% (<xref ref-type="table" rid="t1">tabla 1</xref>).</p>
			<p>
				<table-wrap id="t1">
					<label>Tabla 1</label>
					<caption>
						<title>Número y porcentaje de nematodos gastroentéricos en bovinos en cuatro regiones del sur de Sonora</title>
					</caption>
					<table style="border: 1px solid black; border collapse: collapse" border="1"> 
						<tbody>
							<tr> 
								<td style="text-align: left;">Nematodos </td> 
								<td style="text-align: left;">Sierra alta Frecuencia </td> 
								<td style="text-align: left;">Porcentaje (%) </td> 
								<td style="text-align: left;">Sierra baja Frecuencia </td> 
								<td style="text-align: left;">Porcentaje (%) </td> 
								<td style="text-align: left;">Valle 1 Frecuencia </td> 
								<td style="text-align: left;">Porcentaje (%) </td> 
								<td style="text-align: left;">Valle 2 Frecuencia </td> 
								<td style="text-align: left;">Porcentaje (%) </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>Haemonchus</italic> spp.</td> 
								<td style="text-align: center;">128  </td> 
								<td style="text-align: center;">79.5 </td> 
								<td style="text-align: center;">15 </td> 
								<td style="text-align: center;">17.85 </td> 
								<td style="text-align: center;">6  </td> 
								<td style="text-align: center;">50 </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>Oesophagostomum</italic> spp.</td> 
								<td style="text-align: center;">65  </td> 
								<td style="text-align: center;">40.37 </td> 
								<td style="text-align: center;">7  </td> 
								<td style="text-align: center;">8.33 </td> 
								<td style="text-align: center;">1  </td> 
								<td style="text-align: center;">8.33 </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>Trichostrongylus</italic> spp. </td> 
								<td style="text-align: center;">56 </td> 
								<td style="text-align: center;"> 34.78 </td> 
								<td style="text-align: center;"> 7 </td> 
								<td style="text-align: center;">  8.33 </td> 
								<td style="text-align: center;"> 3 </td> 
								<td style="text-align: center;"> 25 </td> 
								<td style="text-align: center;"> 0 </td> 
								<td style="text-align: center;"> 0 </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>Skrjabinema</italic> spp.</td> 
								<td style="text-align: center;">40  </td> 
								<td style="text-align: center;">24.84 </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">1  </td> 
								<td style="text-align: center;">8.33 </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>Cooperia</italic> spp.</td> 
								<td style="text-align: center;">23  </td> 
								<td style="text-align: center;">14.28 </td> 
								<td style="text-align: center;">49 </td> 
								<td style="text-align: center;">58.33 </td> 
								<td style="text-align: center;">1  </td> 
								<td style="text-align: center;">8.33 </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>Strongyloides</italic> spp.</td> 
								<td style="text-align: center;">18  </td> 
								<td style="text-align: center;">11.18 </td> 
								<td style="text-align: center;">4  </td> 
								<td style="text-align: center;">4.76 </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>Ostertagia</italic> spp.</td> 
								<td style="text-align: center;">14  </td> 
								<td style="text-align: center;">8.69 </td> 
								<td style="text-align: center;">15 </td> 
								<td style="text-align: center;">17.85 </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>Toxacara</italic> spp.</td> 
								<td style="text-align: center;">1  </td> 
								<td style="text-align: center;">0.62 </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
							</tr>
						</tbody>
					</table>
				</table-wrap>
			</p>
			
			<p>Las infecciones por nematodos gastroentéricos se presentaron de uno a ocho géneros, las más frecuentes fueron: sencilla 43.47% (70/161), doble 25.46% (41/161) y triple 20.49% (33/161) (<xref ref-type="table" rid="t2">tabla 2</xref>).</p>
			<p>
				<table-wrap id="t2">
					<label>Tabla 2</label>
					<caption>
						<title>Tipo de infección por nematodos gastroentéricos en bovinos cuatro regiones del sur de Sonora</title>
					</caption>
					<table style="border: 1px solid black; border collapse: collapse" border="1"> 
						<tbody>
							<tr> 
								<td> </td> 
								<td align="center">Sierra alta </td> 
								<td align="center"> Porcentaje </td> 
								<td align="center">Sierra baja </td> 
								<td align="center"> Porcentaje </td> 
								<td align="center">Valle 1  </td> 
								<td align="center"> Porcentaje </td> 
								<td align="center">Valle 2  </td> 
								<td align="center"> Porcentaje </td> 
							</tr> 
							<tr> 
								<td align="center">Tipo de infección </td> 
								<td align="center"> Frecuencia</td> 
								<td align="center">(%) </td> 
								<td align="center"> Frecuencia</td> 
								<td align="center">(%) </td> 
								<td align="center"> Frecuencia</td> 
								<td align="center">(%) </td> 
								<td align="center"> Frecuencia</td> 
								<td align="center">(%) </td> 
							</tr> 
							<tr> 
								<td align="center">Simple </td> 
								<td align="center">70 </td> 
								<td align="center">43.47 </td> 
								<td align="center">68 </td> 
								<td align="center">80.9 </td> 
								<td align="center">2  </td> 
								<td align="center">28.5 </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
							</tr> 
							<tr> 
								<td align="center">Doble </td> 
								<td align="center">41 </td> 
								<td align="center">25.46 </td> 
								<td align="center">16 </td> 
								<td align="center">19.04 </td> 
								<td align="center">5  </td> 
								<td align="center">71.43 </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
							</tr> 
							<tr> 
								<td align="center">Triple </td> 
								<td align="center">33 </td> 
								<td align="center">20.49 </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
							</tr> 
							<tr> 
								<td align="center">Cuádruple </td> 
								<td align="center">16 </td> 
								<td align="center">9.93 </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
							</tr> 
							<tr> 
								<td align="center">Quíntuple </td> 
								<td align="center">1  </td> 
								<td align="center">0.62 </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
								<td align="center">0  </td> 
							</tr>
						</tbody>
					</table>
				</table-wrap>
			</p>
			
			<p>En la <italic>Sierra baja</italic> se encontró: 56% (97/173) becerros positivos y 43.93% (76/173) negativos a los parásitos en estudio. La distribución por género se encontró para nematodos 86.6% (84/97), positivos y protozoarios 23.71% (23/97). El rango de MacMaster fue: nematodos 50-300 HGH y protozoarios 50-200 OGH.</p>
			<p>Los nematodos más frecuentes fueron: <italic>Cooperia</italic> spp. 58.33%, <italic>Haemonchus</italic> spp. 17.85% y <italic>Ostertagia</italic> spp<italic>.</italic> 17.85% (<xref ref-type="table" rid="t1">tabla 1</xref>).</p>
			<p>Con respecto a las infecciones por nematodos gastroentéricos, se presentaron de uno a seis géneros, las dos más frecuentes fueron: sencilla 80.9% y doble 19.04% (<xref ref-type="table" rid="t2">tabla 2</xref>).</p>
			<p>En el estudio las zonas de <italic>Sierra alta</italic> y <italic>Sierra baja</italic> fueron positivos a nematodos en becerros, lo cual concuerda con reportes en donde la prevalencia de PGE en becerros está presente y aumenta en los meses próximos al año de edad; la prevalencia más alta se presenta en becerros de los 4 a los 12 meses de edad, y la mayor frecuencia entre 6 y 9 meses (<xref ref-type="bibr" rid="B3">Colina <italic>et al</italic>., 2013</xref>). Otro factor importante a considerar es la convivencia de los becerros con los bovinos adultos, cuando son portadores de PGE contaminan el forraje y se favorece la infección de los becerros (<xref ref-type="bibr" rid="B6">Encalada <italic>et al</italic>., 2009</xref>).</p>
			<p>Al manejo del ganado en la sierra del estado de Sonora, se le conoce como “corridas”, éstas se realizan una o dos veces al año, es la mejor temporada entre los meses de octubre a abril del siguiente año. Los adultos reciben manejo reproductivo y sanitario como la desparasitación y vacunación; los becerros son separados y la mayoría van a corrales de acopio previo a la exportación. Los bovinos adultos que quedan en la explotación al ser desparasitados una vez, no es suficiente para controlar las poblaciones de PGE; estos contaminan las áreas de pastoreo y los becerros al ser infectados se evidencia por los resultados de una intensidad de infección para PGE de baja (0-500 HGH) a media (550-1000 HGH); se provoca un retardo en el crecimiento, reducción de la productividad y la reinfección de los becerros por la contaminación del forraje (<xref ref-type="bibr" rid="B6">Encalada <italic>et al</italic>., 2009</xref>).</p>
			<p>Con respecto a los géneros de PGE encontrados, varió en cada región de la sierra, lo cual es congruente con un estudio realizado, en donde se indica que los nematodos <italic>Haemonchus</italic> spp., <italic>Mecistocirrus</italic> spp., <italic>Trichostrongylus</italic> spp., <italic>Cooperia</italic> spp., y <italic>Oesophagostomum</italic> spp, son considerados importantes desde el punto de vista patológico y epidemiológico en diversas zonas geo-ecológicas, templadas y cálidas (<xref ref-type="bibr" rid="B28">Vázquez <italic>et al</italic>., 2004</xref>). En otras regiones de México se muestra la distribución, diversidad de la frecuencia y de géneros de PGE en bovinos en diferentes estados, y dan la pauta de la adaptación que tienen a los diferentes ecosistemas como el subtropical y tropical (<xref ref-type="bibr" rid="B18">Quiroz, 2011</xref>; <xref ref-type="bibr" rid="B7">Fernández <italic>et al</italic>., 2015</xref>; <xref ref-type="bibr" rid="B8">Figueroa <italic>et al</italic>., 2018</xref>; <xref ref-type="bibr" rid="B17">Pinilla <italic>et al</italic>., 2018</xref>). Los resultados de las dos regiones de la sierra muestran un avance importante en el conocimiento de la frecuencia e identificación de PGE, en becerros del sur de Sonora.</p>
			<p>En la región <italic>Valle 1,</italic> se encontró: 17.56% (39/222) de positivos y 82.43% (183/222) negativos a parásitos gastroentéricos. Con respecto al tipo de género para nematodos 17.94% (7/39) y protozoarios 82.05% (32/39) de positivos, respectivamente. El rango de MacMaster para cada género parasitario fue: nematodos 50-1100 HGH y protozoarios 50-3250 OGH.</p>
			<p>En las infecciones por nematodos gastroentéricos se presentaron de uno a cinco géneros, predominando la doble 71.43% y sencilla 28.5%.</p>
			<p>En la región <italic>Valle 2,</italic> no se encontró la presencia de PGE y para protozoarios se obtuvo 46% (23/50) positivos, el rango de MacMaster fue de 50-100 OGH.</p>
			<p>Los resultados para NGE de las regiones <italic>Valle 1</italic> y <italic>Valle 2</italic>, son de menor frecuencia y esto puede ser influido por la edad los animales del muestreo que eran adultos (<xref ref-type="bibr" rid="B6">Encalada <italic>et al</italic>., 2009</xref>), el manejo sanitario de desparasitación del hato antes del muestreo; así como a las condiciones de clima semiárido de la región (<xref ref-type="bibr" rid="B13">Martínez y Merino, 2011</xref>; <xref ref-type="bibr" rid="B1">Baumgard y Rhoads, 2013</xref>), lo cual no favorece la formación y viabilidad de las larvas infectantes en el ambiente (<xref ref-type="table" rid="t2">tabla 2</xref>).</p>
			<p>Con respecto a los protozoarios en la <italic>Sierra alta</italic>
				<bold>,</bold> las tres especies más frecuentes fueron: <italic>E. bovis</italic> 69.65%, <italic>E. alabamensis</italic> 34.48% y <italic>E. ellipsoidalis</italic> 24.13%. En la <italic>Sierra baja</italic> predominaron <italic>E. bovis</italic> 65.21% y <italic>E. alabamensis</italic> 43.47%. En la región <italic>Valle 1</italic> la más abundante fue <italic>E. bovis</italic> con 46.5%. En <italic>Valle 2</italic> se encontró a <italic>E. ellipsoidalis</italic> y <italic>E. bukidonensis</italic> con 25 % respectivamente (<xref ref-type="table" rid="t3">tabla 3</xref>).</p>
			<p>
				<table-wrap id="t3">
					<label>Tabla 3</label>
					<caption>
						<title>Número y porcentaje de Eimerias identificadas de bovinos de cuatro regiones del sur de Sonora</title>
					</caption>
					<table style="border: 1px solid black; border collapse: collapse" border="1"> 
						<tbody>
							<tr> 
								<td style="text-align: center;">Protozoario </td> 
								<td style="text-align: center;">Sierra alta </td> 
								<td style="text-align: center;">Porcentaje </td> 
								<td style="text-align: center;">Sierra baja </td> 
								<td style="text-align: center;">Porcentaje </td> 
								<td style="text-align: center;">Valle 1 </td> 
								<td style="text-align: center;">Porcentaje </td> 
								<td style="text-align: center;">Valle 2 </td> 
								<td style="text-align: center;">Porcentaje </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;">  </td> 
								<td style="text-align: center;">Frecuencia </td> 
								<td style="text-align: center;">(%) </td> 
								<td style="text-align: center;">Frecuencia </td> 
								<td style="text-align: center;">(%) </td> 
								<td style="text-align: center;">Frecuencia </td> 
								<td style="text-align: center;">(%) </td> 
								<td style="text-align: center;">Frecuencia </td> 
								<td style="text-align: center;">(%) </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>E. bovius </italic></td> 
								<td style="text-align: center;">101 </td> 
								<td style="text-align: center;">69.65 </td> 
								<td style="text-align: center;">13 </td> 
								<td style="text-align: center;">62.21 </td> 
								<td style="text-align: center;">15 </td> 
								<td style="text-align: center;">46.5 </td> 
								<td style="text-align: center;">1 </td> 
								<td style="text-align: center;">12.5 </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>E. alabamensis </italic></td> 
								<td style="text-align: center;">50 </td> 
								<td style="text-align: center;">34.48 </td> 
								<td style="text-align: center;">10 </td> 
								<td style="text-align: center;">43.47 </td> 
								<td style="text-align: center;">2 </td> 
								<td style="text-align: center;">6.25 </td> 
								<td style="text-align: center;">1 </td> 
								<td style="text-align: center;">12.5 </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>E. ellipsoidalis</italic></td> 
								<td style="text-align: center;">35 </td> 
								<td style="text-align: center;">24.13 </td> 
								<td style="text-align: center;">3 </td> 
								<td style="text-align: center;">13.04 </td> 
								<td style="text-align: center;">6 </td> 
								<td style="text-align: center;">21.85 </td> 
								<td style="text-align: center;">2 </td> 
								<td style="text-align: center;">25 </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>E.</italic><italic>auburnensis</italic></td> 
								<td style="text-align: center;">34 </td> 
								<td style="text-align: center;">23.44 </td> 
								<td style="text-align: center;">2 </td> 
								<td style="text-align: center;">8.69 </td> 
								<td style="text-align: center;">3 </td> 
								<td style="text-align: center;">9.37 </td> 
								<td style="text-align: center;">0 </td> 
								<td style="text-align: center;">0 </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>E.</italic><italic>bukidnonensis</italic>
								</td> 
								<td style="text-align: center;">28 </td> 
								<td style="text-align: center;">19.31 </td> 
								<td style="text-align: center;">0 </td> 
								<td style="text-align: center;">0 </td> 
								<td style="text-align: center;">4 </td> 
								<td style="text-align: center;">12.5 </td> 
								<td style="text-align: center;">2 </td> 
								<td style="text-align: center;">25 </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>E.</italic><italic>subspherica</italic>
								</td> 
								<td style="text-align: center;">26 </td> 
								<td style="text-align: center;">17.93 </td> 
								<td style="text-align: center;">1 </td> 
								<td style="text-align: center;">4.34 </td> 
								<td style="text-align: center;">7 </td> 
								<td style="text-align: center;">21.85 </td> 
								<td style="text-align: center;">1 </td> 
								<td style="text-align: center;">12.5 </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;"><italic>E. zurnii</italic>
								</td> 
								<td style="text-align: center;">20 </td> 
								<td style="text-align: center;">13.79 </td> 
								<td style="text-align: center;">1 </td> 
								<td style="text-align: center;">4.34 </td> 
								<td style="text-align: center;">9 </td> 
								<td style="text-align: center;">28.15 </td> 
								<td style="text-align: center;">1 </td> 
								<td style="text-align: center;">12.5 </td> 
							</tr>
						</tbody>
					</table>
				</table-wrap>
			</p>
			
			<p>Las infecciones de coccidia en <italic>Sierra alta</italic> se presentaron de uno a seis géneros de <italic>Eimeria</italic>, las tres más frecuentes fueron: sencilla 33.10%, doble 30.34% y triple 16.55%. En <italic>Sierra baja</italic>: sencilla 43.48% y doble 56.52%. Región <italic>Valle 1</italic> fueron simple 71.88% y doble 15.63% y región <italic>Valle 2</italic> simple 66.66% y doble con 33.33% (<xref ref-type="table" rid="t4">tabla 4</xref>).</p>
			<p>
				<table-wrap id="t4">
					<label>Tabla 4</label>
					<caption>
						<title>Tipo de infección por Eimeria en bovinos de cuatro regiones del sur del estado de Sonora</title>
					</caption>
					<table style="border: 1px solid black; border collapse: collapse" border="1"> 
						<tbody>
							<tr> 
								<td style="text-align: center;">Tipo de infección </td> 
								<td style="text-align: center;">
									<p>Sierra alta</p>
									<p>Cantidad</p>
								</td> 
								<td style="text-align: center;">
									<p>Porcentaje</p>
									<p>(%)</p>
								</td> 
								<td style="text-align: center;">
									<p>Sierra baja</p>
									<p>Cantidad</p>
								</td> 
								<td style="text-align: center;">
									<p>Porcentaje</p>
									<p>(%)</p>
								</td> 
								<td style="text-align: center;">
									<p>Valle 1</p>
									<p>Cantidad</p>
								</td> 
								<td style="text-align: center;">
									<p>Porcentaje</p>
									<p>(%)</p>
								</td> 
								<td style="text-align: center;">
									<p>Valle 2</p>
									<p>Frecuencia</p>
								</td> 
								<td style="text-align: center;">
									<p>Porcentaje</p>
									<p>(%)</p> </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;">Simple </td> 
								<td style="text-align: center;">48 </td> 
								<td style="text-align: center;">33.1 </td> 
								<td style="text-align: center;">10 </td> 
								<td style="text-align: center;">43.48 </td> 
								<td style="text-align: center;">23 </td> 
								<td style="text-align: center;">71.88 </td> 
								<td style="text-align: center;">4  </td> 
								<td style="text-align: center;">66.66 </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;">Doble </td> 
								<td style="text-align: center;">44 </td> 
								<td style="text-align: center;">30.34 </td> 
								<td style="text-align: center;">13 </td> 
								<td style="text-align: center;">56.52 </td> 
								<td style="text-align: center;">5  </td> 
								<td style="text-align: center;">15.63 </td> 
								<td style="text-align: center;">2  </td> 
								<td style="text-align: center;">33.33 </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;">Triple </td> 
								<td style="text-align: center;">24 </td> 
								<td style="text-align: center;">16.55 </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">3  </td> 
								<td style="text-align: center;">9.6 </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;">Cuádruple </td> 
								<td style="text-align: center;">20 </td> 
								<td style="text-align: center;">13.79 </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;">Quíntuple </td> 
								<td style="text-align: center;">6  </td> 
								<td style="text-align: center;">4.13 </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">1  </td> 
								<td style="text-align: center;">3.13 </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
							</tr> 
							<tr> 
								<td style="text-align: center;">Séxtuple </td> 
								<td style="text-align: center;">3  </td> 
								<td style="text-align: center;">2.06 </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
								<td style="text-align: center;">0  </td> 
							</tr>
						</tbody>
					</table>
				</table-wrap>
			</p>
			<p>En este estudio las zonas de <italic>Valle 1</italic> y <italic>Valle 2</italic>, fueron positivos varias especies de <italic>Eimeria;</italic> lo cual concuerda con trabajos en donde se reporta que existen al menos 13 especies de <italic>Eimeria</italic> que infectan a bovinos, pero solo algunas son muy patógenas como <italic>E. bovis</italic> y <italic>E. zuernii</italic> (<xref ref-type="bibr" rid="B4">Das <italic>et al</italic>., 2015</xref>; <xref ref-type="bibr" rid="B16">Pascoti <italic>et al</italic>., 2011</xref>) y <italic>E. alabamensis</italic> (<xref ref-type="bibr" rid="B4">Das <italic>et al</italic>., 2015</xref>). En corrales techados se reporta a <italic>E. ellipsoidalis</italic>, <italic>E. alabamensis</italic> y <italic>E. auburnensis</italic> (<xref ref-type="bibr" rid="B14">Mitchell <italic>et al</italic>., 2012</xref>; <xref ref-type="bibr" rid="B9">Forslid <italic>et al</italic>., 2015</xref>).</p>
			<p>Las infecciones por <italic>Eimeria</italic> pueden provocar diarrea severa, heces que contienen sangre, fibrina y tejido intestinal; los signos son fiebre, dolor, tenesmo, anemia, deshidratación, debilidad, anemia y pérdida de peso (<xref ref-type="bibr" rid="B16">Pascoti <italic>et al</italic>., 2011</xref>). Este complejo de efectos tiene consecuencias clínicas y económicas considerables. En áreas endémicas los becerros de primer año tienen alto riesgo de desarrollar coccidiosis clínica, y son comunes las infecciones por varias especies; siendo más comunes <italic>E. bovis</italic>, <italic>E. zuernii</italic> y <italic>E. alabamensis,</italic> durante las primeras dos semanas de vida (<xref ref-type="bibr" rid="B22">Samson <italic>et al</italic>., 2006</xref>; <xref ref-type="bibr" rid="B16">Pascoti <italic>et al</italic>., 2011</xref>), y hasta los 12 meses de edad (<xref ref-type="bibr" rid="B14">Mitchell <italic>et al</italic>., 2012</xref>; <xref ref-type="bibr" rid="B9">Forslid <italic>et al</italic>., 2015</xref>). Se estima que las pérdidas por reducción en la eficiencia alimenticia son del 25 a 60% por becerro, y se predijo con modelo simulador una pérdida del 6 a 8% anual por eimeriosis (<xref ref-type="bibr" rid="B11">Lassen y Osstergaard, 2012</xref>).</p>
			<p>Se han realizado diversos estudios en diferentes países como Perú, Brasil, Estados Unidos, India e Inglaterra; en donde las Eimerias más frecuentes identificadas fueron: <italic>E. bovis, E. zuernii, E. auburnensis</italic>, <italic>E. ellipsoidalis</italic>; con menor frecuencia <italic>E. subspherica</italic>, <italic>E. bukidnonesis</italic>, <italic>E. cylindrica</italic>, <italic>E. canadienses y E. alabamensis</italic> (<xref ref-type="bibr" rid="B16">Pascoti <italic>et al</italic>., 2011</xref>; <xref ref-type="bibr" rid="B14">Mitchell <italic>et al</italic>., 2012</xref>; <xref ref-type="bibr" rid="B3">Colina <italic>et al</italic>., 2013</xref>; <xref ref-type="bibr" rid="B12">Lucas <italic>et al</italic>., 2014</xref>; <xref ref-type="bibr" rid="B4">Das <italic>et al</italic>., 2015</xref>).</p>
			<p>En México los estudios realizados en bovinos de Yucatán y Guerrero, las Eimerias más frecuentes fueron: <italic>E. bovis</italic>, <italic>E. ellipsoidalis</italic> y <italic>E. zuerni;</italic> en menor proporción se encontró a: <italic>E. auburnensis</italic> y <italic>E. canadensis</italic> y <italic>E. parva</italic> (<xref ref-type="bibr" rid="B20">Rodríguez <italic>et al</italic>., 1996</xref>; <xref ref-type="bibr" rid="B8">Figueroa <italic>et al</italic>., 2018</xref>).</p>
			<p>En la presente investigación, los cuatro sectores tuvieron presencia de <italic>E. bovis</italic>, <italic>E. alabamensis, E. ellipsoidalis</italic> y <italic>E. auburnensis</italic>, su frecuencia varía por los diferentes grupos de edad y las condiciones ambientales; lo cual indica la capacidad de viabilidad de los ooquistes esporulados, que es más de un año (<xref ref-type="bibr" rid="B12">Lucas <italic>et al</italic>., 2014</xref>). La mayoría de los estudios de infecciones naturales de <italic>Eimeria</italic> en bovinos confirman que las becerras menores de un año tienen una alta prevalencia de infección y eliminan el mayor número de ooquistes por heces al ambiente (<xref ref-type="bibr" rid="B3">Colina <italic>et al</italic>., 2013</xref>; <xref ref-type="bibr" rid="B12">Lucas <italic>et al</italic>., 2014</xref>). La trasmisión está influenciada por los bovinos adultos que son portadores asintomáticos, que favorecen la infección frecuente en animales jóvenes (<xref ref-type="bibr" rid="B14">Mitchell <italic>et al</italic>., 2012</xref>; <xref ref-type="bibr" rid="B3">Colina <italic>et al</italic>., 2013</xref>); la cual puede ocurrir en las áreas de descanso o “echaderos” y pastoreo dentro de los agostaderos, así como en los corrales de alojamiento.</p>
		</sec>
		<sec sec-type="conclusions">
			<title>CONCLUSIÓN</title>
			<p>Se demuestra que los bovinos criados en la zona de estudio mostraron una frecuencia de baja 17.56% a alta 83.03% de parásitos gastroentéricos, con la presencia de uno a ocho géneros de nematodos; y de uno a siete géneros de protozoarios.</p>
		</sec>
	</body>
	<back>
		<ack>
			<title>AGRADECIMIENTOS</title>
			<p>Los autores agradecen el apoyo al donativo otorgado por el Programa de Fomento y Apoyo a la Investigación (PROFAPI) del Instituto Tecnológico de Sonora, por el donativo otorgado para la realización de este trabajo (PROFAPI_2018_0047 y PROFAPI_ 2019_0052).</p>
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	<sub-article article-type="translation" id="s1" xml:lang="en">
		<front-stub>
			<article-categories>
				<subj-group subj-group-type="heading">
					<subject>Original article</subject>
				</subj-group>
			</article-categories>
			<title-group>
				<article-title>Frequency of gastrointestinal parasites in cattle at the southern of Sonora, Mexico</article-title>
			</title-group>
			<abstract>
				<title>ABSTRACT</title>
				<p>Commonly gastroenteric parasites are a health problem in extensive livestock and could be a risk in the productive efficiency in cattle raised at the south of Sonora, Mexico. In order to determine the frequency of the different gastrointestinal parasitic genera in bovines of the southern region of Sonora, a study was divided in <italic>high-mountain</italic> (n= 218), <italic>low</italic>-<italic>mountain</italic> (n= 173), V<italic>alley1</italic> (n= 222) and <italic>Valley2</italic> (n= 50) regions. The feces were collected from adult cattle and calves (5 to 6 months of age) from January to March and December 2018; January to February 2019. The samples were analyzed by flotation and MacMaster techniques. The morphology was determined obtaining the L3 stage by coproculture. The <italic>Eimerias</italic> were identified prior to sporulation. The 83.03%, 56.0% and 17.56% were positive for gastrointestinal parasites in <italic>high-mountain</italic>, <italic>low</italic>-<italic>mountain and</italic> V<italic>alley1</italic> respectively. <italic>Valley2</italic> was negative for nematodes, but 43% were positive for <italic>Eimerias</italic>. The cattle in the study area showed a <italic>low</italic> 17.56% <italic>to high</italic> 83.03% frequency of gastroenteric parasites with the presence of one to eight genera of nematode and one to seven of <italic>Eimeria</italic>. </p>
			</abstract>
			<kwd-group xml:lang="en">
				<title>Keywords:</title>
				<kwd>Cattle</kwd>
				<kwd>nematodes</kwd>
				<kwd><italic>eimeria</italic> semiarid</kwd>
				<kwd>mountain</kwd>
			</kwd-group>
		</front-stub>
		<body>
			<sec sec-type="intro">
				<title>INTRODUCTION</title>
				<p>The production of beef cattle in Sonora is developed in more than 15 million hectares of
					summer pastures, 83% of the state area is used, with 1.5 million head of cattle
						(<xref ref-type="bibr" rid="B5">Denogean <italic>et al</italic>.,
						2013</xref>). For the farmer, the weather and ecological conditions are a
					restrictive element for adequate production, which depends on the potential of
					the forage to meet nutritional needs (<xref ref-type="bibr" rid="B5">Denogean
							<italic>et al</italic>., 2013</xref>; <xref ref-type="bibr" rid="B19"
						>Retes <italic>et al</italic>., 2013</xref>). The delicate balance of
					nutrients and health of cattle is at constant risk by being exposed to
					infections by gastroenteric parasites (PGE), which significantly reduce food
					consumption, feed conversion and weight gain, with morbidity and mortality in
					animals young people (<xref ref-type="bibr" rid="B25">Stromberg <italic>et
							al</italic>., 2012</xref>).</p>
				<p>In the abomasum, the secretory cells that affect the quantity and quality of the hydrochloric acid are damaged, which modifies the pH value up to 6.5 and the efficiency of the digestion and absorption of nutrients is reduced; affects the mineral and protein metabolism, in subclinical and chronic presentation the animals reduce their food consumption by 15 to 20%, which decreases weight gain or there is weight loss; Therefore, nutritional deficiencies are increased and livestock productivity is reduced (<xref ref-type="bibr" rid="B27">Torres, 2006</xref>; <xref ref-type="bibr" rid="B2">Biswajit <italic>et al</italic>., 2017</xref>; <xref ref-type="bibr" rid="B15">Oliviera <italic>et al</italic>., 2017</xref>). In some cases, acute anorexia, anemia, toxemia, tissue damage and death can be observed; usually in young animals in growth and sometimes in adults (<xref ref-type="bibr" rid="B10">Johanssos, 2017</xref>).</p>
				<p>The potential economic impact of parasites in Mexico was estimated and obtained for gastroenteric nematodes US $ 445.10 and for coccidia (<italic>Eimeria</italic> spp.) US $ 23.78 million, based on the national population in 2013 of 32.4 million cattle (<xref ref-type="bibr" rid="B21">Rodríguez <italic>et al</italic>., 2017</xref>). Due to the detrimental effects on production and health, it is important to have information on the presence of PGE in the region.</p>
				<p>The objective of this research was to determine the frequency and genera of gastroenteric parasites in cattle from four sectors of southern Sonora, Mexico.</p>
			</sec>
			<sec sec-type="materials|methods">
				<title>MATERIAL AND METHODS</title>
				<p>Geographic location. The study was conducted in a sector of the <italic>High-mountain</italic> and the <italic>Low-mountain</italic>, as well as two sectors of the southern Sonora Valley. In the <italic>High-mountain</italic> sector, work was carried out in the Yécora municipality, which is located 215 kilometers north of Obregón city, at an altitude of 1540 meters; The prevailing climate is mild subhumid with rains for most of the year. In February and March, the temperature reaches 24.0 °C and the annual average is 24.4 °C, with annual average precipitation of 944 mm (<xref ref-type="bibr" rid="B24">SMN, 2018</xref>).</p>
				<p>In the <italic>Low-mountain</italic> sector, work was carried out in the Rosario municipality, in Tesopaco town, located at an altitude of 450 meters; it has a semi-dry or semi-warm climate, with a maximum average temperature of 29.2 °C and minimum of 14.2 °C. Rains predominate during July and August, with an annual average rainfall of 610.1 mm (<xref ref-type="bibr" rid="B24">SMN, 2018</xref>).</p>
				<p>Sampling. In stockpiles of the <italic>High-mountain</italic> sector, 218 calves (140 males and 78 females) were sampled and from <italic>Low-mountain</italic> to 173 calves (130 males and 43 females); they were all cattle breeding grounds, mostly creole weaned or at the beginning of weaning, between 5 and 10 months of age, raised extensively and free grazing. The samples from the Valley 1 region were 222 samples from 8 herds of adult dairy cattle; from the Valley 2 region, there were 50 adult cattle in summer pastures. Sampling was carried out from January to March and December 2018, and from January to February 2019, to conduct an observational and cross-sectional study (<xref ref-type="bibr" rid="B26">Thursfield, 2018</xref>). Sampling was carried out for convenience in the collection pens and in the herds, where sampling was allowed (<xref ref-type="bibr" rid="B23">Scheaffer <italic>et al</italic>., 2012</xref>).</p>
				<p>To the stool samples, the qualitative flotation and quantitative technique of MacMaster was performed to obtain eggs per gram of feces (HGH), oocysts per gram of feces (OGH); co-culture and Baerman (<xref ref-type="bibr" rid="B30">Yacob <italic>et al</italic>., 2009</xref>); In the latter, the larvae (L3) present were identified based on their morphological characteristics (<xref ref-type="bibr" rid="B17">Pinilla <italic>et al</italic>., 2018</xref>). Sporulation technique was performed to identify Eimerias (<xref ref-type="bibr" rid="B14">Mitchell <italic>et al</italic>., 2012</xref>). Through the Microsoft Excel 2016 program, the results shown in descriptive statistics were obtained (<xref ref-type="bibr" rid="B29">Wayne, 2014</xref>).</p>
			</sec>
			<sec sec-type="results|discussion">
				<title>RESULTS AND DISCUSSION</title>
				<p>In the High-mountain were: 83.03% (181/218) positive calves and 16.97% (37/218) negative to gastroenteric parasites. The gender type for nematodes was 88.95% (161/181) positive, cestodes 19.33% (35/181) and protozoa 80.11% (145/181). The MacMaster range for each genus was: 50-900 HGH nematodes, 50-6850 HGH cestodes, 50-5050 OGH protozoa.</p>
				<p>The most frequent genera were: <italic>Haemonchus</italic> spp. 79.5%, <italic>Oesophagostomum</italic> spp. 40.37% and <italic>Trichostrongylus</italic> spp. 34.78% (<xref ref-type="table" rid="t5">table 1</xref>).</p>
				<p>
					<table-wrap id="t5">
						<label>Table 1</label>
						<caption>
							<title>Number and percentage of gastroenteric nematodes in cattle in four regions of southern Sonora</title>
						</caption>
						<table style="border: 1px solid black; border collapse: collapse" border="1"> 
							<tbody>
								<tr> 
									<td style="text-align: left;">Nematodos </td> 
									<td style="text-align: left;">
										<p>High-mountain</p>
										<p>Frequency</p> </td> 
									<td style="text-align: left;">Porcentage (%) </td> 
									<td style="text-align: left;">
										<p>Low-mountain</p>
										<p>Frequency</p> </td> 
									<td style="text-align: left;">Porcentage (%) </td> 
									<td style="text-align: left;">
										<p>Valley 1</p>
										<p>Frecuency</p>
									</td> 
									<td style="text-align: left;">Porcentage (%) </td> 
									<td style="text-align: left;">
										<p>Valley 2</p>
										<p>Frecuency</p> </td> 
									<td style="text-align: left;">Porcentage (%) </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>Haemonchus</italic>spp.</td> 
									<td style="text-align: center;">128  </td> 
									<td style="text-align: center;">79.5 </td> 
									<td style="text-align: center;">15 </td> 
									<td style="text-align: center;">17.85 </td> 
									<td style="text-align: center;">6  </td> 
									<td style="text-align: center;">50 </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>Oesophagostomum</italic> spp.</td> 
									<td style="text-align: center;">65  </td> 
									<td style="text-align: center;">40.37 </td> 
									<td style="text-align: center;">7  </td> 
									<td style="text-align: center;">8.33 </td> 
									<td style="text-align: center;">1  </td> 
									<td style="text-align: center;">8.33 </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>Trichostrongylus</italic> spp. </td> 
									<td style="text-align: center;">56 </td> 
									<td style="text-align: center;"> 34.78 </td> 
									<td style="text-align: center;">7 </td> 
									<td style="text-align: center;">  8.33 </td> 
									<td style="text-align: center;"> 3 </td> 
									<td style="text-align: center;"> 25 </td> 
									<td style="text-align: center;"> 0 </td> 
									<td style="text-align: center;">0 </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>Skrjabinema</italic> spp.</td> 
									<td style="text-align: center;">40  </td> 
									<td style="text-align: center;">24.84 </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">1  </td> 
									<td style="text-align: center;">8.33 </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>Cooperia</italic> spp.</td> 
									<td style="text-align: center;">23  </td> 
									<td style="text-align: center;">14.28 </td> 
									<td style="text-align: center;">49 </td> 
									<td style="text-align: center;">58.33 </td> 
									<td style="text-align: center;">1  </td> 
									<td style="text-align: center;">8.33 </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>Strongyloides</italic> spp.</td> 
									<td style="text-align: center;">18  </td> 
									<td style="text-align: center;">11.18 </td> 
									<td style="text-align: center;">4  </td> 
									<td style="text-align: center;">4.76 </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>Ostertagia</italic> spp.</td> 
									<td style="text-align: center;">14  </td> 
									<td style="text-align: center;">8.69 </td> 
									<td style="text-align: center;">15 </td> 
									<td style="text-align: center;">17.85 </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>Toxacara</italic> spp.</td> 
									<td style="text-align: center;">1  </td> 
									<td style="text-align: center;">0.62 </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
								</tr>
							</tbody>
						</table>
					</table-wrap>
				</p>
				
				<p>Gastroenteric nematode infections occurred in one to eight genera, the most frequent being: single 43.47% (70/161), double 25.46% (41/161) and triple 20.49% (33/161) (<xref ref-type="table" rid="t6">table 2</xref>).</p>
				<p>
					<table-wrap id="t6">
						<label>Table 2</label>
						<caption>
							<title>Type of infection by gastroenteric nematodes in cattle four regions of southern Sonora</title>
						</caption>
						<table style="border: 1px solid black; border collapse: collapse" border="1"> 
							<tbody>
								<tr> 
									<td> </td> 
									<td align="center">High-mountain </td> 
									<td align="center"> Porcentage </td> 
									<td align="center">Low-mountain </td> 
									<td align="center"> Porcentage </td> 
									<td align="center">Valley 1 </td> 
									<td align="center"> Porcentage </td> 
									<td align="center">Valley 2 </td> 
									<td align="center"> Porcentage </td> 
								</tr> 
								<tr> 
									<td align="center">Type of infection </td> 
									<td align="center"> Frecuency</td> 
									<td align="center">(%) </td> 
									<td align="center"> Frecuency</td> 
									<td align="center">(%) </td> 
									<td align="center"> Frecuency</td> 
									<td align="center">(%) </td> 
									<td align="center"> Frecuency</td> 
									<td align="center">(%) </td> 
								</tr> 
								<tr> 
									<td align="center">Simple </td> 
									<td align="center">70 </td> 
									<td align="center">43.47 </td> 
									<td align="center">68 </td> 
									<td align="center">80.9 </td> 
									<td align="center">2  </td> 
									<td align="center">28.5 </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
								</tr> 
								<tr> 
									<td align="center">Double </td> 
									<td align="center">41 </td> 
									<td align="center">25.46 </td> 
									<td align="center">16 </td> 
									<td align="center">19.04 </td> 
									<td align="center">5  </td> 
									<td align="center">71.43 </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
								</tr> 
								<tr> 
									<td align="center">Triple </td> 
									<td align="center">33 </td> 
									<td align="center">20.49 </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
								</tr> 
								<tr> 
									<td align="center">Quadruple </td> 
									<td align="center">16 </td> 
									<td align="center">9.93 </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
								</tr> 
								<tr> 
									<td align="center">Quíntuple </td> 
									<td align="center">1  </td> 
									<td align="center">0.62 </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
									<td align="center">0  </td> 
								</tr>
							</tbody>
						</table>
					</table-wrap>
				</p>
				<p>In the Low-mountain it was found: 56% (97/173) positive calves and 43.93% (76/173) negative to the parasites under study. The distribution by gender was found for nematodes 86.6% (84/97), positive and protozoan 23.71% (23/97). The MacMaster range was: 50- 300 HGH nematodes and 50-200 OGH protozoan.</p>
				<p>The most frequent nematodes were: <italic>Cooperia</italic> spp. 58.33%, <italic>Haemonchus</italic> spp. 17.85% and <italic>Ostertagia</italic> spp. 17.85% (<xref ref-type="table" rid="t1">table 1</xref>).</p>
				<p>With respect to gastroenteric nematode infections, there were one to six genera, the two most frequent were: single 80.9% and double 19.04% (<xref ref-type="table" rid="t2">table 2</xref>).</p>
				<p>In the study the areas of High-mountain and Low-mountain were positive for nematodes in calves, which is consistent with reports where the prevalence of PGE in calves is present and increases in the months close to the year of age; the highest prevalence occurs in calves from 4 to 12 months of age, and the highest frequency between 6 and 9 months (<xref ref-type="bibr" rid="B3">Colina <italic>et al</italic>., 2013</xref>). Another important factor to consider is the coexistence of the calves with the adult bovines, when they are carriers of PGE they contaminate the forage and the infection of the calves is favored (<xref ref-type="bibr" rid="B6">Encalada <italic>et al</italic>., 2009</xref>).</p>
				<p>The management of livestock in Sonora state mountains is known as &quot;runs&quot;, these are done once or twice a year, is the best season between the months of October to April of the following year. Adults receive reproductive and sanitary management such as deworming and vaccination; Calves are separated and most go to pre-export stockpiles. The adult cattle that remain on the farm when dewormed once, it is not enough to control the populations of PGE; these contaminate grazing areas and calves when infected are evidenced by the results of an infection intensity for PGE from low (0-500 HGH) to medium (550-1000 HGH); It causes a delay in growth, reduced productivity and reinfection of calves due to forage contamination (<xref ref-type="bibr" rid="B6">Encalada <italic>et al</italic>., 2009</xref>).</p>
				<p>Regarding the genera of PGE found, it varied in each region of the mountain, which is consistent with a study conducted, which indicates that the nematodes <italic>Haemonchus</italic> spp., <italic>Mecistocirrus</italic> spp., <italic>Trichostrongylus</italic> spp., <italic>Cooperia</italic> spp., and <italic>Oesophagostomum</italic> spp, are considered important from a pathological and epidemiological point of view in various geo-ecological, temperate and warm areas (<xref ref-type="bibr" rid="B28">Vázquez <italic>et al.,</italic> 2004</xref>). In other regions of Mexico the distribution, diversity of the frequency and genus of PGE in cattle in different states is shown, and they give the guideline of the adaptation that they have to the different ecosystems such as the subtropical and tropical (<xref ref-type="bibr" rid="B18">Quiroz, 2011</xref>; <xref ref-type="bibr" rid="B7">Fernández <italic>et al</italic>., 2015</xref>; <xref ref-type="bibr" rid="B8">Figueroa <italic>et al</italic>., 2018</xref>; <xref ref-type="bibr" rid="B17">Pinilla <italic>et al</italic>., 2018</xref>). The results of the two regions of the mountains show an important advance in the knowledge of the frequency and identification of PGE, in calves in southern Sonora.</p>
				<p>In the <italic>Valley</italic> 1 region, 17.56% (39/222) positive and 82.43% (183/222) negative for gastroenteric parasites were found. Regarding the type of gender for nematodes 17.94% (7/39) and protozoa 82.05% (32/39) positive, respectively. The MacMaster range for each parasitic genus was: 50-1100 HGH nematodes and 50-3250 OGH protozoa.</p>
				<p>In infections due to gastroenteric nematodes, there were one to five genera, with a double 71.43% and simple 28.5%.</p>
				<p>In the Valley 2 region, the presence of PGE was not found and for protozoa, 46% (23/50) positive were obtained, the MacMaster range was 50-100 OGH.</p>
				<p>The results for NGE of the Valle 1 and Valle 2 regions are less frequent and this may be influenced by the age of the animals in the sampling that were adults (<xref ref-type="bibr" rid="B6">Encalada <italic>et al.,</italic> 2009</xref>), the sanitary management of deworming of the herd before sampling; as well as the semi-arid climate conditions of the region (<xref ref-type="bibr" rid="B13">Martínez and Merino, 2011</xref>; <xref ref-type="bibr" rid="B1">Baumgard and Rhoads, 2013</xref>), which does not favor the formation and viability of the infecting larvae in the environment (<xref ref-type="table" rid="t2">table 2</xref>).</p>
				<p>With respect to the protozoa in the High-mountain, the three most frequent species were:</p>
				<p><italic>E. bovis</italic> 69.65%, <italic>E. alabamensis</italic> 34.48% and <italic>E. ellipsoidalis</italic> 24.13%. In the Low- mountain, <italic>E. bovis</italic> 65.21% and <italic>E. alabamensis</italic> predominated 43.47%. In the Valle 1 region the most abundant was <italic>E. bovis</italic> with 46.5%. In Valley 2 <italic>E. ellipsoidalis</italic> and <italic>E. bukidonensis</italic> were found with 25% respectively (<xref ref-type="table" rid="t7">table 3</xref>).</p>
				<p>
					<table-wrap id="t7">
						<label>Table 3</label>
						<caption>
							<title>Number and percentage of Eimerias identified from cattle from four regions of southern Sonora</title>
						</caption>
						<table style="border: 1px solid black; border collapse: collapse" border="1"> 
							<tbody>
								<tr> 
									<td style="text-align: center;">Protozoario </td> 
									<td style="text-align: center;">Sierra alta </td> 
									<td style="text-align: center;">Porcentaje </td> 
									<td style="text-align: center;">Sierra baja </td> 
									<td style="text-align: center;">Porcentaje </td> 
									<td style="text-align: center;">Valle 1 </td> 
									<td style="text-align: center;">Porcentaje </td> 
									<td style="text-align: center;">Valle 2 </td> 
									<td style="text-align: center;">Porcentaje </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;">  </td> 
									<td style="text-align: center;">Frecuencia </td> 
									<td style="text-align: center;">(%) </td> 
									<td style="text-align: center;">Frecuencia </td> 
									<td style="text-align: center;">(%) </td> 
									<td style="text-align: center;">Frecuencia </td> 
									<td style="text-align: center;">(%) </td> 
									<td style="text-align: center;">Frecuencia </td> 
									<td style="text-align: center;">(%) </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>E. bovius </italic></td> 
									<td style="text-align: center;">101 </td> 
									<td style="text-align: center;">69.65 </td> 
									<td style="text-align: center;">13 </td> 
									<td style="text-align: center;">62.21 </td> 
									<td style="text-align: center;">15 </td> 
									<td style="text-align: center;">46.5 </td> 
									<td style="text-align: center;">1 </td> 
									<td style="text-align: center;">12.5 </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>E. alabamensis </italic></td> 
									<td style="text-align: center;">50 </td> 
									<td style="text-align: center;">34.48 </td> 
									<td style="text-align: center;">10 </td> 
									<td style="text-align: center;">43.47 </td> 
									<td style="text-align: center;">2 </td> 
									<td style="text-align: center;">6.25 </td> 
									<td style="text-align: center;">1 </td> 
									<td style="text-align: center;">12.5 </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>E. ellipsoidalis</italic></td> 
									<td style="text-align: center;">35 </td> 
									<td style="text-align: center;">24.13 </td> 
									<td style="text-align: center;">3 </td> 
									<td style="text-align: center;">13.04 </td> 
									<td style="text-align: center;">6 </td> 
									<td style="text-align: center;">21.85 </td> 
									<td style="text-align: center;">2 </td> 
									<td style="text-align: center;">25 </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>E.</italic><italic>auburnensis</italic></td> 
									<td style="text-align: center;">34 </td> 
									<td style="text-align: center;">23.44 </td> 
									<td style="text-align: center;">2 </td> 
									<td style="text-align: center;">8.69 </td> 
									<td style="text-align: center;">3 </td> 
									<td style="text-align: center;">9.37 </td> 
									<td style="text-align: center;">0 </td> 
									<td style="text-align: center;">0 </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>E.</italic><italic>bukidnonensis</italic>
									</td> 
									<td style="text-align: center;">28 </td> 
									<td style="text-align: center;">19.31 </td> 
									<td style="text-align: center;">0 </td> 
									<td style="text-align: center;">0 </td> 
									<td style="text-align: center;">4 </td> 
									<td style="text-align: center;">12.5 </td> 
									<td style="text-align: center;">2 </td> 
									<td style="text-align: center;">25 </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>E.</italic><italic>subspherica</italic>
									</td> 
									<td style="text-align: center;">26 </td> 
									<td style="text-align: center;">17.93 </td> 
									<td style="text-align: center;">1 </td> 
									<td style="text-align: center;">4.34 </td> 
									<td style="text-align: center;">7 </td> 
									<td style="text-align: center;">21.85 </td> 
									<td style="text-align: center;">1 </td> 
									<td style="text-align: center;">12.5 </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;"><italic>E. zurnii</italic>
									</td> 
									<td style="text-align: center;">20 </td> 
									<td style="text-align: center;">13.79 </td> 
									<td style="text-align: center;">1 </td> 
									<td style="text-align: center;">4.34 </td> 
									<td style="text-align: center;">9 </td> 
									<td style="text-align: center;">28.15 </td> 
									<td style="text-align: center;">1 </td> 
									<td style="text-align: center;">12.5 </td> 
								</tr>
							</tbody>
						</table>
					</table-wrap>
				</p>
				
				<p>Coccidia infections in High-mountain occurred from one to six genera of <italic>Eimeria</italic>, the three most frequent were: single 33.10%, double 30.34% and triple 16.55%. In Low-mountain: 43.48% single and 56.52% double. Valley 1 region was simple 71.88% and double 15.63% and Valley 2 region simple 66.66% and double with 33.33% (<xref ref-type="table" rid="t8">table 4</xref>).</p>
				<p>
					<table-wrap id="t8">
						<label>Table 4</label>
						<caption>
							<title>Type of Eimeria infection in cattle from four regions of the southern state of Sonora</title>
						</caption>
						<table style="border: 1px solid black; border collapse: collapse" border="1"> 
							<tbody>
								<tr> 
									<td style="text-align: center;">Type de infection </td> 
									<td style="text-align: center;">
										<p>High-mountain</p>
										<p>Quantily</p>
									</td> 
									<td style="text-align: center;">
										<p>Porcentage</p>
										<p>(%)</p>
									</td> 
									<td style="text-align: center;">
										<p>Low-mountain</p>
										<p>Quantily</p>
									</td> 
									<td style="text-align: center;">
										<p>Porcentage</p>
										<p>(%)</p>
									</td> 
									<td style="text-align: center;">
										<p>Valley 1</p>
										<p>Quantily</p>
									</td> 
									<td style="text-align: center;">
										<p>Porcentage</p>
										<p>(%)</p>
									</td> 
									<td style="text-align: center;">
										<p>Valley 2</p>
										<p>Frecuency</p>
									</td> 
									<td style="text-align: center;">
										<p>Porcentage</p>
										<p>(%)</p> </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;">Simple </td> 
									<td style="text-align: center;">48 </td> 
									<td style="text-align: center;">33.1 </td> 
									<td style="text-align: center;">10 </td> 
									<td style="text-align: center;">43.48 </td> 
									<td style="text-align: center;">23 </td> 
									<td style="text-align: center;">71.88 </td> 
									<td style="text-align: center;">4  </td> 
									<td style="text-align: center;">66.66 </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;">Doble </td> 
									<td style="text-align: center;">44 </td> 
									<td style="text-align: center;">30.34 </td> 
									<td style="text-align: center;">13 </td> 
									<td style="text-align: center;">56.52 </td> 
									<td style="text-align: center;">5  </td> 
									<td style="text-align: center;">15.63 </td> 
									<td style="text-align: center;">2  </td> 
									<td style="text-align: center;">33.33 </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;">Triple </td> 
									<td style="text-align: center;">24 </td> 
									<td style="text-align: center;">16.55 </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">3  </td> 
									<td style="text-align: center;">9.6 </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;">Quadruple </td> 
									<td style="text-align: center;">20 </td> 
									<td style="text-align: center;">13.79 </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;">Quíntuple </td> 
									<td style="text-align: center;">6  </td> 
									<td style="text-align: center;">4.13 </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">1  </td> 
									<td style="text-align: center;">3.13 </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
								</tr> 
								<tr> 
									<td style="text-align: center;">Sextuple </td> 
									<td style="text-align: center;">3  </td> 
									<td style="text-align: center;">2.06 </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
									<td style="text-align: center;">0  </td> 
								</tr>
							</tbody>
						</table>
					</table-wrap>
				</p>
				
				<p>In this study the zones of Valley 1 and Valley 2, several species of <italic>Eimeria</italic> were positive; This is consistent with works that report that there are at least 13 species of <italic>Eimeria</italic> that infect cattle, but only some are very pathogenic such as <italic>E. bovis</italic> and <italic>E. zuernii</italic> (<xref ref-type="bibr" rid="B4">Das <italic>et al</italic>., 2015</xref>; <xref ref-type="bibr" rid="B16">Pascoti <italic>et al</italic>., 2011</xref> ) and <italic>E. alabamensis</italic> (<xref ref-type="bibr" rid="B4">Das <italic>et al</italic>., 2015</xref>). In roofed pens, <italic>E. ellipsoidalis, E. alabamensis</italic> and <italic>E. auburnensis</italic> are reported (<xref ref-type="bibr" rid="B14">Mitchell <italic>et al</italic>., 2012</xref>; <xref ref-type="bibr" rid="B9">Forslid <italic>et al</italic>., 2015</xref>).</p>
				<p><italic>Eimeria</italic> infections can cause severe diarrhea, feces containing blood, fibrin and intestinal tissue; the signs are fever, pain, tenesmus, anemia, dehydration, weakness, anemia and weight loss (<xref ref-type="bibr" rid="B16">Pascoti <italic>et al</italic>., 2011</xref>). This complex of effects has considerable clinical and economic consequences. In endemic areas, first-year calves are at high risk of developing clinical coccidiosis, and infections by several species are common; <italic>E. bovis, E. zuernii</italic> and <italic>E. alabamensis</italic> being more common, during the first two weeks of life (<xref ref-type="bibr" rid="B22">Samson <italic>et al</italic>., 2006</xref>; <xref ref-type="bibr" rid="B16">Pascoti <italic>et</italic> al., 2011</xref>), and up to 12 months of age (<xref ref-type="bibr" rid="B14">Mitchell <italic>et al</italic>. , 2012</xref>; <xref ref-type="bibr" rid="B9">Forslid <italic>et al</italic>., 2015</xref>). It is estimated that losses due to reduction in feed efficiency are 25 to 60% percalf, and a 6 to 8% annual loss due to eimeriosis was predicted with a simulator model (<xref ref-type="bibr" rid="B11">Lassen and Osstergaard, 2012</xref>).</p>
				<p>Various studies have been conducted in different countries such as Peru, Brazil, the United States, India and England; where the most frequent Eimerias identified were: <italic>E. bovis, E. zuernii, E. auburnensis, E. ellipsoidalis;</italic> less frequently <italic>E. subspherica, E. bukidnonesis, E. cylindrica, E. Canadians</italic> and <italic>E. alabamensis</italic> (<xref ref-type="bibr" rid="B16">Pascoti <italic>et al</italic>., 2011</xref>; <xref ref-type="bibr" rid="B14">Mitchell <italic>et al.,</italic> 2012</xref>; <xref ref-type="bibr" rid="B3">Colina <italic>et al</italic>., 2013</xref>; <xref ref-type="bibr" rid="B12">Lucas <italic>et al</italic>., 2014</xref>; <xref ref-type="bibr" rid="B4">Das <italic>et a</italic>l., 2015</xref>).</p>
				<p>In Mexico, studies conducted on bovines in Yucatán and Guerrero, the most frequent Eimerias were: <italic>E. bovis, E. ellipsoidalis</italic> and <italic>E. zuerni</italic>; to a lesser extent, we found<italic>: E. auburnensis</italic> and <italic>E. canadensis</italic> and <italic>E. parva</italic> (<xref ref-type="bibr" rid="B20">Rodríguez <italic>et al</italic>., 1996</xref>; <xref ref-type="bibr" rid="B8">Figueroa <italic>et al</italic>., 2018</xref>).</p>
				<p>In the present investigation, the four sectors had presence of E. bovis, <italic>E. alabamensis</italic>, <italic>E. ellipsoidalis</italic> and <italic>E. auburnensis</italic>, their frequency varies by different age groups and environmental conditions; this indicates the viability of sporulated oocysts, which is more than one year (<xref ref-type="bibr" rid="B12">Lucas <italic>et al</italic>., 2014</xref>). Most studies of natural <italic>Eimeria</italic> infections in cattle confirm that calves under one year of age have a high prevalence of infection and eliminate the greatest number of oocysts by feces into the environment (<xref ref-type="bibr" rid="B3">Colina et al., 2013</xref>; <xref ref-type="bibr" rid="B12">Lucas et al., 2014</xref>). Transmission is influenced by adult cattle that are asymptomatic carriers, which favor frequent infection in young animals (<xref ref-type="bibr" rid="B14">Mitchell <italic>et al</italic>., 2012</xref>; <xref ref-type="bibr" rid="B3">Colina <italic>et al</italic>., 2013</xref>); which can occur in the rest areas or &quot;dumps&quot; and grazing within the summer pastures, as well as in the housing pens.</p>
			</sec>
			<sec sec-type="conclusions">
				<title>CONCLUSION</title>
				<p>It is shown that cattle raised in the study area showed a frequency of low 17.56% to high 83.03% of gastroenteric parasites, with the presence of one to eight nematode genera; and from one to seven genera of protozoa.</p>
				<p><bold>ACKNOWLEDGMENT</bold></p>
				<p>The authors thank the support for the donation granted by the Program for the Promotion and Support of Research (PROFAPI) of the Technological Institute of Sonora, for the donation granted for the realization of this work (PROFAPI_2018_0047 and PROFAPI_ 2019_0052).</p>
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