High genetic correlation between resistance to Haemonchus contortus and to Trichostrongylus colubriformis in INRA 401 sheep

• Published in: Veterinary parasitology Vol. 119; no. 1; pp. 51 - 58
• Main Authors: Gruner, L, Bouix, J, Brunel, J.C
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05-01-2004; Elsevier
• Subjects: Animal biology; Animals; Feces - parasitology; Female; Genetic Predisposition to Disease; Genetics; Haemonchiasis - genetics; Haemonchiasis - immunology; Haemonchiasis - parasitology; Haemonchiasis - veterinary; Haemonchus - immunology; Haemonchus contortus; Immunity, Innate - genetics; Life Sciences; Male; Nematoda; Parasite Egg Count - veterinary; Resistance; Selection, Genetic; Sheep; Sheep Diseases - genetics; Sheep Diseases - parasitology; Sheep-nematoda; Trichostrongylosis - genetics; Trichostrongylosis - immunology; Trichostrongylosis - parasitology; Trichostrongylosis - veterinary; Trichostrongylus; Trichostrongylus - immunology; Trichostrongylus colubriformis; Veterinary medicine and animal Health; Resistance; Haemonchus contortus; Genetics; Sheep-nematoda; Trichostrongylus colubriformis; RESISTANCE GENETIQUE
• ISSN: 0304-4017; 1873-2550
• DOI: 10.1016/j.vetpar.2003.10.014

To compare the protection acquired by infection with
Haemonchus contortus or
Trichostrongylus colubriformis, successive cross infections with the two species were conducted in two genetically similar groups of 150 ewe lambs from 30 sires of INRA 401 breed. At 6 and 7.5 months of age, each group received two doses of 10
000 L3 separated by a treatment of one of the species, followed by a similar infection with the second species at 9 and 11.5 months. Faecal egg counts (FECs) were done 28 and 35 days after each dose. There were very high genetic correlation within and between species suggesting that the environmental conditions were very similar. The heritability of FEC of
H. contortus ranged from 0.39 to 0.48 and the genetic correlations between FEC after the first and second infections with the same or different species were all near 1. Selection against this species could be done on the response to only one dose. For
T. colubriformis, only the response to challenge infection had a similar heritability (0.47); the genetic correlations within and among species were also near one. These results will assist the selection of sheep resistant to nematode parasites.