<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>The objective was to identify the optimal stage of production to evaluate the resistance of Pelibuey ewes against gastrointestinal nematodes (GIN). Faecal egg count (FEC) was used to classify the ewes as resistant, sensible or intermediate against GIN. Forty-seven ewes were mating during 30 d. The gestation was verified by ultrasonography, and the breeding date was used to calculate the productive stages. Faeces were taken weekly to determine the FEC. Blood samples were taken to determine the packed cell volume (PCV), the peripheral eosinophils count (PEC), plasma protein concentration (PP), and Immunoglobulin A (IgA) against <italic>Haemonchus contortus</italic>. The body condition score (BCS) was recorded at each visit. Six moments during the study (early, mid and late gestation; early, mid and late lactation) were considered. The ewes were classified according to FEC (mean FEC ± three standard errors). The higher FEC occurred during all lactation stages than during early and mid-gestation stages (P&lt;0.05). PCV, PP, and BCS during early gestation stage were higher than shown during the lactation stages (P&lt;0.01). The PEC and IgA were higher during all lactation stages than early and mid-gestation stages (P&lt;0.05). Concerning the type of birth, double births showed higher FEC than single birth (P&lt;0.01). The highest values of accuracy (100 %) and concordance (Youden's J = 1.0) were found during early lactation. Therefore, it is concluded that the optimal stage of production to evaluate phenotypic resistance against GIN infections in Pelibuey ewes was during the early lactation.</p>
</abstract>

The objective was to identify the optimal stage of production to evaluate the resistance of Pelibuey ewes against gastrointestinal nematodes (GIN). Faecal egg count (FEC) was used to classify the ewes as resistant, sensible or intermediate against GIN. Forty-seven ewes were mating during 30 d. The gestation was verified by ultrasonography, and the breeding date was used to calculate the productive stages. Faeces were taken weekly to determine the FEC. Blood samples were taken to determine the packed cell volume (PCV), the peripheral eosinophils count (PEC), plasma protein concentration (PP), and Immunoglobulin A (IgA) against Haemonchus contortus. The body condition score (BCS) was recorded at each visit. Six moments during the study (early, mid and late gestation; early, mid and late lactation) were considered. The ewes were classified according to FEC (mean FEC ± three standard errors). The higher FEC occurred during all lactation stages than during early and mid-gestation stages (P<0.05). PCV, PP, and BCS during early gestation stage were higher than shown during the lactation stages (P<0.01). The PEC and IgA were higher during all lactation stages than early and mid-gestation stages (P<0.05). Concerning the type of birth, double births showed higher FEC than single birth (P<0.01). The highest values of accuracy (100 %) and concordance (Youden's J = 1.0) were found during early lactation. Therefore, it is concluded that the optimal stage of production to evaluate phenotypic resistance against GIN infections in Pelibuey ewes was during the early lactation.

Optimum timing for assessing phenotypic resistance against gastrointestinal nematodes in Pelibuey ewes

Laboratorio de Enfermedades Tropicales y Transmitidas por Vectores, Division Academica de Ciencias Agropecuarias

Facultad de Medicina Veterinaria y Zootecnia, Campus de Ciencias Biologicas y Agropecuarias

Helminthologia

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

The objective was to identify the optimal stage of production to evaluate the resistance of Pelibuey ewes against gastrointestinal nematodes (GIN). Faecal egg...

Optimum timing for assessing phenotypic resistance against gastrointestinal nematodes in Pelibuey ewes

Published Online: Dec 31, 2023

Page range: 348 - 356

Received: Jan 25, 2023

Accepted: Oct 27, 2023

DOI: https://doi.org/10.2478/helm-2023-0038

Keywords
Gestation, Lactation, FEC, PCV, Eosinophils, Pelibuey

© 2023 C. V. Zaragoza-Vera et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Optimum timing for assessing phenotypic resistance against gastrointestinal nematodes in Pelibuey ewes

Published Online: Dec 31, 2023

Page range: 348 - 356

Received: Jan 25, 2023

Accepted: Oct 27, 2023

DOI: https://doi.org/10.2478/helm-2023-0038

KeywordsGestation, Lactation, FEC, PCV, Eosinophils, Pelibuey

© 2023 C. V. Zaragoza-Vera et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
Gestation, Lactation, FEC, PCV, Eosinophils, Pelibuey