{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T11:21:33Z","timestamp":1783336893401,"version":"3.54.6"},"reference-count":42,"publisher":"FapUNIFESP (SciELO)","issue":"2","license":[{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"am","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Universidad Autonoma Chapingo"},{"name":"Universidad Juarez Autonoma de Tabasco"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Rev. Bras. Parasitol. Vet."],"abstract":"<jats:p>Abstract The aim of this study was to determine the phenotypic variables commonly evaluated to segregate Pelibuey lambs as resistant or susceptible to Haemonchus contortus infection. Twenty-one lambs were infected over 3 consecutive weeks with 200 larvae per kg of body weight. The lambs were dewormed 42 days after the first infection. A second infection was performed during the growth stage (32 weeks of age), and a third infection at 1 year of age. After the first infection, the lambs were segregated as resistant (&lt;761 eggs per gram of feces, EPG) or susceptible (&gt;761 EPG). Packed cell volume (PCV) and total plasma protein (TPPr) during the first stage were lower (25.14% and 6.56 g\/dL) than during the second stage (30.06% and 7.1 g\/dL, respectively). A notable decrease in EPG values in both groups occurred from the first to the second experimental infection (resistant: 510 \u00b1 663 to 26 \u00b1 83 EPG; susceptible: 3621 \u00b1 6246 to 76 \u00b1 361 EPG). Pelibuey lambs can be segregated as susceptible or resistant to H. contortus infection from 5 months of age following the first infection. The most informative phenotypic markers for segregation identified in the present study were EPG, PCV, and TPPr.<\/jats:p>","DOI":"10.1590\/s1984-29612026022","type":"journal-article","created":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T11:00:58Z","timestamp":1783335658000},"source":"Crossref","is-referenced-by-count":0,"title":["Phenotypic assessment of resistance in a flock of Pelibuey lambs experimentally infected with Haemonchus contortus"],"prefix":"10.1590","volume":"35","author":[{"given":"Maritza","family":"Zaragoza-Vera","sequence":"first","affiliation":[{"name":"Universidad Aut\u00f3noma de Yucat\u00e1n,  M\u00e9xico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0333-7787","authenticated-orcid":false,"given":"Roberto","family":"Gonz\u00e1lez-Gardu\u00f1o","sequence":"additional","affiliation":[{"name":"Universidad Aut\u00f3noma Chapingo,  M\u00e9xico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Oswaldo Margarito","family":"Torres-Chabl\u00e9","sequence":"additional","affiliation":[{"name":"Universidad Ju\u00e1rez Aut\u00f3noma de Tabasco,  M\u00e9xico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Claudia Virginia","family":"Zaragoza-Vera","sequence":"additional","affiliation":[{"name":"Universidad Ju\u00e1rez Aut\u00f3noma de Tabasco,  M\u00e9xico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guadalupe","family":"Arjona-Jim\u00e9nez","sequence":"additional","affiliation":[{"name":"Universidad Ju\u00e1rez Aut\u00f3noma de Tabasco,  M\u00e9xico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Armando Jacinto","family":"Aguilar-Caballero","sequence":"additional","affiliation":[{"name":"Universidad Aut\u00f3noma de Yucat\u00e1n,  M\u00e9xico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fleider Leiser","family":"Pe\u00f1a-Escalona","sequence":"additional","affiliation":[{"name":"Universidad Polit\u00e9cnica de Texcoco,  M\u00e9xico"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"530","published-online":{"date-parts":[[2026]]},"reference":[{"key":"ref1","doi-asserted-by":"crossref","DOI":"10.1016\/j.smallrumres.2020.106049","article-title":"Influence of litter size at birth or weaning on the proportion of Pelibuey ewes treated with an anthelmintic in a targeted selective scheme in the hot humid tropics","volume":"184","author":"Aguirre-Serrano AM","year":"2020","journal-title":"Small Rumin Res"},{"issue":"1","key":"ref2","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1046\/j.0141-9838.2001.00432.x","article-title":"Mechanisms of immunity to Haemonchus contortus infection in sheep","volume":"24","author":"Balic A","year":"2002","journal-title":"Parasite Immunol"},{"issue":"6","key":"ref3","doi-asserted-by":"crossref","first-page":"495","DOI":"10.1111\/jbg.12424","article-title":"Genetic parameter estimates for gastrointestinal nematode parasite resistance and maternal efficiency indicator traits in Santa In\u00eas breed","volume":"136","author":"Berton MP","year":"2019","journal-title":"J Anim Breed Genet"},{"issue":"8","key":"ref4","doi-asserted-by":"crossref","first-page":"1543","DOI":"10.1590\/1678-5150-pvb-5490","article-title":"Iron supplementation for lambs experimentally infected by Haemonchus contortus: response to anemia and iron store in the bone marrow","volume":"38","author":"Casanova VP","year":"2018","journal-title":"Pesq Vet Bras"},{"issue":"1","key":"ref5","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1016\/j.cvfa.2019.10.001","article-title":"Helminth vaccines in ruminants: from development to application","volume":"36","author":"Claerebout E","year":"2020","journal-title":"Vet Clin North Am Food Anim Pract"},{"issue":"4","key":"ref6","doi-asserted-by":"crossref","first-page":"613","DOI":"10.3390\/ani14040613","article-title":"Genetic parameter estimation and selection for resistance to gastrointestinal nematode parasites in sheep: a review","volume":"14","author":"Cunha SMF","year":"2024","journal-title":"Animals (Basel)"},{"issue":"2","key":"ref7","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/0020-7519(89)90008-8","article-title":"Eosinophil responses in sheep selected for high and low responsiveness to TrichostrongyluKs colubriformis.","volume":"19","author":"Dawkins HJ","year":"1989","journal-title":"Int J Parasitol"},{"key":"ref8","article-title":"Anisuzzaman, Alim MdA, Alam MZ. 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