Evidence for a constitutive cost of host resistance on body fat growth in ewe lambs from lines selected for resistance or susceptibility to experimental infections with Haemonchus contortus - Université de Tours
Article Dans Une Revue International Journal for Parasitology Année : 2024

Evidence for a constitutive cost of host resistance on body fat growth in ewe lambs from lines selected for resistance or susceptibility to experimental infections with Haemonchus contortus

Didier Marcon
  • Fonction : Auteur
  • PersonId : 1206457
Lucie Estivalet
  • Fonction : Auteur
  • PersonId : 1207370
Delphine Serreau
  • Fonction : Auteur
  • PersonId : 1160856
Fabrice Guégnard
  • Fonction : Auteur
  • PersonId : 1206399
Guillaume Sallé

Résumé

Although benefits of selection for host resistance to gastro-intestinal nematodes have long been recognized, its costs on production traits remain unclear. A main difficulty when studying those costs is to disentangle genetic effects due to selection from plastic responses induced by infection. Putative costs of host resistance have been extensively investigated in growing sheep. However, while most of those studies have relied on live weight to assess body growth, more comprehensive assessments accounting for body composition are advocated to detect trade-offs. In this study we used 90 female lambs from lines divergently selected on resistance to Haemonchus contortus that we experimentally infected (n = 60) or not (n = 30) under controlled conditions. As those conditions were defined to enable uninfected lambs to fully express their growth potential, we sought to precisely identify the effects of selection for host resistance on health traits and on growth traits. We assessed muscular and fat growth based on repeated measurements with dorsal ultrasonography for all lambs on farm, and with whole-body computed tomography (CT) scans for a subgroup of 18 infected lambs. Lambs achieved a high growth rate, including infected ones despite their high worm burden (confirmed at necropsy in the subgroup). As expected, lambs from the resistant (R) line were less infected than those from the susceptible (S) line. However, the clear pathogenic effects observed on muscular growth and voluntary feed intake were similar between lines. In contrast, a line difference in body fat was supported both by dorsal and volumetric CT measurements. Specifically, lower fat in the R line compared with the S line was observed equally in infected and uninfected groups, thus providing evidence for a constitutive cost of host resistance. Although this cost is not necessarily disadvantageous in nutrient-rich environments exposing animals to excess fat deposition, its consequences in nutrient-scarce environments may be important to promote sustainable breeding strategies for host resistance.
Fichier principal
Vignette du fichier
2024_Douhard_Int-J-Parasitol_vol-54_p-767-77.pdf (2.38 Mo) Télécharger le fichier
Origine Fichiers éditeurs autorisés sur une archive ouverte
Licence

Dates et versions

hal-04741527 , version 1 (07-01-2025)

Licence

Identifiants

Citer

Frédéric Douhard, Xavier Matthey, Didier Marcon, Camille Coffre-Thomain, Lucie Estivalet, et al.. Evidence for a constitutive cost of host resistance on body fat growth in ewe lambs from lines selected for resistance or susceptibility to experimental infections with Haemonchus contortus. International Journal for Parasitology, 2024, 54 (14), pp.767-777. ⟨10.1016/j.ijpara.2024.09.004⟩. ⟨hal-04741527⟩
14 Consultations
0 Téléchargements

Altmetric

Partager

More