Is selection for resistance and resilience to Haemonchus contortus possible in Morada Nova sheep?

Haehling, Marei Borsch von; Toscano, J. H. B.; Giraldelo, L. A.; Santos, Isabella Barbosa dos; Esteves, S. N.; Benavides, Magda Vieira; Tholon, P.; Chagas, Ana Carolina Souza

doi:10.1016/j.smallrumres.2021.106447

Cited by 6 publications

(11 citation statements)

References 20 publications

(42 reference statements)

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“…These results point out for increased resilience of Morada Nova lambs harbouring β A allele of β‐globin. Lambs of Morada Nova breed were previously characterised as resilient, since more than 88% of animals experimentally infected with H. contortus maintained the PCV above 24%, even when heavily infected 11,51 . However, in our previous study, besides the higher PCV, significantly lower FEC levels and higher birthweight were also observed in Hb‐AA compared to Hb‐BB Morada Nova lambs experimentally infected with H. contortus 9 .…”

Section: Discussionmentioning

confidence: 58%

“…Lambs of Morada Nova breed were previously characterised as resilient, since more than 88% of animals experimentally infected with H. contortus maintained the PCV above 24%, even when heavily infected. 11,51 However, in our previous study, besides the higher PCV, significantly lower FEC levels and higher birthweight were also observed in Hb-AA compared to Hb-BB Morada Nova lambs experimentally infected with H. contortus. as resistant also presented significantly higher counts of eosinophils in the fundic region of the abomasum.…”

Section: Relative Quantification Of Gene Expressionmentioning

confidence: 59%

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Enhanced mucosal response in sheep harbouringβ^Abeta‐globin against haemonchosis

Okino,

Niciura,

Giaretta

et al. 2023

Parasite Immunology

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Association between ovine β‐globin polymorphisms and resistance against haemonchosis was described and related to the mechanism of high oxygen affinity βA ➔ βC switch during anaemia, but there are no studies regarding the involved local host responses. Phenotypic parameters and local responses were evaluated in sheep from two β‐globin haplotypes naturally infected with Haemonchus contortus. Morada Nova lambs were monitored at 63, 84 and 105 days of age for faecal egg counts and packed cell volume (PCV) under natural infection with H. contortus. At 210 days of age, lambs of Hb‐AA and Hb‐BB β‐globin haplotypes were euthanised, and the fundic region of abomasum was sampled for evaluation of microscopic lesions and relative expression of genes related to immune, mucin and lectin activities. Lambs harbouring the βA allele presented an improved resistance/resilience against clinical haemonchosis, showing higher PCV during infection. Hb‐AA animals presented increased eosinophilia in the abomasum compared to Hb‐BB animals, accompanied by higher Th2 profile, mucin and lectin activity transcripts, while the inflammatory response was increased in Hb‐BB animals. This is the first report to demonstrate an enhanced local response in the primary site of H. contortus infection related to βA allele of β‐globin haplotype.

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Section: Discussionmentioning

confidence: 58%

Section: Relative Quantification Of Gene Expressionmentioning

confidence: 59%

Enhanced mucosal response in sheep harbouringβ^Abeta‐globin against haemonchosis

Okino,

Niciura,

Giaretta

et al. 2023

Parasite Immunology

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“…Parasite occurrence depends, for example, on elements such as: temperature, rainfall, soil, topography, pasture type and management, species, breed, age, physiological and nutritional status and animal management (Ruas & Berne, 2001). Morada Nova lambs are resilient to GIN and adults are resistant (Issakowicz et al, 2016;Toscano et al, 2019;Haehling et al, 2021;Okino et al, 2021). Thus, we believe that the values calculated here are underestimates in relation to more susceptible breeds, such as Suffolk and Ile de France (Amarante et al, 2004).…”

Section: Discussionmentioning

confidence: 66%

Economic impact of gastrointestinal nematodes in Morada Nova sheep in Brazil

Chagas

Tupy

Santos

et al. 2022

Rev. Bras. Parasitol. Vet.

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This study evaluated the economic impact of gastrointestinal nematode (GIN) infection in Morada Nova lambs under different parasite chemical control conditions. For this, 246 lambs, in the rainy and dry season, were randomized into groups according to their anthelmintic treatment with levamisole: control (CT: no treatment); routine treatment (RT: treated every 42 days); and targeted selective treatment (TST: treated according to the average daily weight gain, DWG). From 63 days of age (D63) to D210, the lambs were weighed and monitored for GIN infection parameters. Spending on anthelmintics in the production system was 1.3% of the total economic result. The economic result per animal (R$ 5.00 = US$ 1.00) was higher in the RT group, amounting to US$ 6.60 in the rainy and US$ 5.69 in the dry season, due to higher DWG. Thus, RT presented economic results 14.4% and 10.9% higher than CT, and 7.2% and 1.9% higher than TST, in the rainy and dry season, respectively. However, fast development of resistance made RT unfeasible. Here, the economic impact of GIN infection on a national scale is discussed, demonstrating its importance and the impossibility of profitable and sustainable sheep production without adequate control.

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“…To be able to improve a trait through genetic selection, it needs to be heritable and show genetic variation in the population. Studies have shown that FEC [5,22,27,28,32,38], FAMACHA© score [27], PCV [28,32], Ig levels [5], and other traits [5,22,32] used to measure resistance in sheep are heritable, with genetic and phenotypic variations among breeds and individuals, enabling the use of these traits in genetic selection programs [1]. In addition, it is also important to understand how resistance/resilience correlates to the production traits, making possible to optimally select for different traits in breeding programs [39].…”

Section: Genetic Parameters For Traits Measuring Resistance/resiliencementioning

confidence: 99%

“…Natural selection happens in wild populations, where the resistant animals survive and mate, generating offspring capable of dealing with infections [20]. There are known sheep breeds that are naturally resistant to GINs all around the world, including the Santa Inês [21], Morada Nova [22], Katahdin [23,24], St. Croix [23,24], Gulf Coast Native [24], Florida Native [24], Red Massai [25], Barbados Black Belly [24,25], and others. Among the susceptible sheep breeds, several studies demonstrated genetic variation within them, making it possible to select for more resistant animals [2,26].…”

Section: Introductionmentioning

confidence: 99%

Genetic Parameter Estimation and Selection for Resistance to Gastrointestinal Nematode Parasites in Sheep—A Review

Cunha,

Willoughby,

Schenkel

et al. 2024

Animals

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Gastrointestinal nematodes (GINs) are a major problem affecting sheep production systems worldwide. The flocks infected with GINs can undergo significant economic losses due to a decrease in productivity, the animals’ deaths, and the costs associated with treatments. The over-reliance on anthelmintics in the past years to eliminate GINs has resulted in the development of resistance against the available commercial anthelmintics. Genetically resistant animals can be used in mating systems to improve the overall flock resistance. This review aimed to summarize the estimated genetic parameters for resistance traits and genetic gains through the use of genetic/genomic selection for resistance to GINs in sheep. Heritability estimates from the literature ranged from 0.00 to 0.46 for fecal egg counts, 0.12 to 0.37 for packed cell volume/hematocrit, 0.07 to 0.26 for FAffa MAlan CHArt (FAMACHA©), from 0.10 to 0.37 for blood parameters, and 0.19 for Immunoglobulin A. Genetic correlations between traits measuring resistance to GINs and production traits ranged from negative to positive values in the literature. Genetic gains are possible when genetic/genomic selection for GIN resistance is applied. Therefore, genetic/genomic selection can be used to improve flocks’ resistance to GINs as a sustainable approach in sheep production systems.

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Is selection for resistance and resilience to Haemonchus contortus possible in Morada Nova sheep?

Cited by 6 publications

References 20 publications

Enhanced mucosal response in sheep harbouringβ^Abeta‐globin against haemonchosis

Enhanced mucosal response in sheep harbouringβ^Abeta‐globin against haemonchosis

Economic impact of gastrointestinal nematodes in Morada Nova sheep in Brazil

Genetic Parameter Estimation and Selection for Resistance to Gastrointestinal Nematode Parasites in Sheep—A Review

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Is selection for resistance and resilience to Haemonchus contortus possible in Morada Nova sheep?

Cited by 6 publications

References 20 publications

Enhanced mucosal response in sheep harbouringβAbeta‐globin against haemonchosis

Enhanced mucosal response in sheep harbouringβAbeta‐globin against haemonchosis

Economic impact of gastrointestinal nematodes in Morada Nova sheep in Brazil

Genetic Parameter Estimation and Selection for Resistance to Gastrointestinal Nematode Parasites in Sheep—A Review

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Enhanced mucosal response in sheep harbouringβ^Abeta‐globin against haemonchosis

Enhanced mucosal response in sheep harbouringβ^Abeta‐globin against haemonchosis