Assessment of genetic variability of resistance to gastrointestinal nematode parasites in Creole goats in the humid tropics

• Published in: Journal of animal science Vol. 79; no. 7; pp. 1706 - 1712
• Main Authors: Mandonnet, N, Aumont, G, Fleury, J, Arquet, R, Varo, H, Gruner, L, Bouix, J, Khang, J. V
• Format: Journal Article
• Language: English
• Published: Savoy, IL Am Soc Animal Sci 01-07-2001; American Society of Animal Science; Oxford University Press
• Subjects: Animal productions; Animal reproduction; Animals; Biological and medical sciences; Breeding - methods; Feces - parasitology; Female; Fundamental and applied biological sciences. Psychology; Gastrointestinal Diseases - genetics; Gastrointestinal Diseases - immunology; Gastrointestinal Diseases - veterinary; Genes; Genetic Variation; Goat Diseases - genetics; Goat Diseases - immunology; Goats; Haemonchus contortus; Humidity; Immunity, Innate - genetics; Infections; Life Sciences; Male; Nematode Infections - genetics; Nematode Infections - immunology; Nematode Infections - veterinary; Parasite Egg Count - veterinary; Terrestrial animal productions; Trichostrongylus colubriformis; Tropical Climate; Vertebrates; Central America; Guadeloupe; America; West Indies; Tropical zone; Haemonchus contortus; Genetic variability; Ruminant animal; Body weight; Genetic character; Breeding scheme; Disease resistance; Goat; Nematoda; Ungulata; Trichostrongylus colubriformis; Intertropical zone; Farming animal; Parasite; Parasitosis; Experimental study; Infection; Vertebrata; Mammalia; Sensitivity resistance; Gastrointestinal diseases; Genetic improvement; Helmintha; Nemathelminthia; Heritability; Artiodactyla; Invertebrata; RESISTANCE
• ISSN: 0021-8812; 1525-3163; 0021-8812
• DOI: 10.2527/2001.7971706x

Goat production is widespread in the tropics. Goats are very susceptible to gastrointestinal nematode infection, but there is less evidence of their genetic resistance. Genetic resistance of Creole goats to gastrointestinal nematodes has been studied at Guadeloupe in the French West Indies since 1995. The objective of this research was to investigate genetic variation for resistance to gastrointestinal nematode infection, in order to introduce this trait into breeding schemes. Genetic variability was assessed within a Creole experimental flock. Forty-nine sire groups were characterized at weaning and 55 during fattening after weaning. Kids were naturally infected, mainly by Haemonchus contortus and Trichostrongylus colubriformis. Fecal egg counts were determined once at weaning and every 6 and 7 wk after drenching during fattening. Blood samples were collected every 7 wk during fattening for determination of packed cell volume. Live weights were recorded at weaning and at the beginning and middle of every infection period during fattening. Genetic parameters were estimated using the REML for multivariate animal models. The heritability estimate for transformed fecal egg count was 0.37+/-0.06 at weaning. During fattening, it increased from 0.14+/-0.05 at 4 mo to 0.33+/-0.06 at 10 mo. Heritabilities of packed cell volume ranged from 0.10 to 0.33. At weaning, maternal heritability of fecal egg count reached 0.26 and direct heritability 0.20. After 6 mo of age, maternal effects were found to be unimportant for fecal egg count and packed cell volume. Live weights presented significant genetic variability. Genetic relationships between fecal egg counts and live weight in infected pastures were never significant. Genetic correlations between packed cell volume and live weight decreased from 0.47 to 0.10 from weaning to 10 mo of age. These results demonstrated the feasibility of breeding for improved resistance to nematodes in Creole kids.