Organic rabbit farming: should we be afraid of gastro-intestinal parasites?

International audienceOur trial aimed to study the gastro-intestinal parasitism in pasture raised rabbits, during three seasons: winter 2014/2015, summer 2015 and spring 2016. For every season, at weaning two groups of five movable cages (three rabbits per cage) were disposed either in a sainfoin or a grass pasture. Nematodes eggs and Eimeria oocysts were counted on a weekly basis in faeces, oocysts were identified at species level every two weeks. At slaughter (100-day old), the liver was examined and the digestive tract was sampled to count the number of nematodes. The type of pasture had no significant effect on egg excretion or on nematode prevalence and intensity, or oocyst excretion of all species combined. Spring 2016 was characterized by a high prevalence of Trichostrongylus sp. (93% of rabbits) and a 50% increase in the total excretion of oocysts, particularly in sainfoin pasture (6.5 M.OPG) where the rotation times was shorter. No diarrhoea was observed during the trial, neither were intestinal macro-lesions in the slaughtered rabbits. However, 64% of the livers presented white nodules due to Eimeria stiedai. A negative correlation between the intensity of infection by Trichostrongylus sp. and daily gain was observed. The mean excretion of E. flavescens may explain a part of the lower daily weight gain (-5 g/d) observed, whatever the pasture type, at spring 2016 compared to the two other seasons. Our first results suggested increasing the pasture rotation time over the two months requested by current organic rabbit farming regulation in France to reduce worm infections