Free-range use and intestinal parasites in organic/free-range laying hens

Abstract

Intestinal parasites are commonly found in non-cage laying hens. Some of these parasites reduce welfare and performance. Anthelmintics are not always effective and may lead to residues in eggs and in the environment. The aim of this study was to evaluate the relationship between free-range use and infections with intestinal parasites in organic laying hens, in order to identify directions for preventive measures. The study included 40 farms in 3 countries. Per farm, 6 pooled soil and 14 pooled fecal samples were analyzed using the McMaster method. Range use on flock level was assessed in several ways. Of the fecal samples, 71% (median) contained ascarid eggs, with a median of 143 eggs/gram (EPG). Capillaria eggs were found in 7% (median) of the fecal samples (median EPG = 5). Of the soil samples, 0% (median) contained ascarids eggs. Capillaria eggs were only detected in Italian soil samples. No relationship was found between parasite eggs in feces and range use or flock performance (% of lay, mortality). The low number of ascarid eggs and regionally the absence of Capillaria eggs in free-range soil suggest to focus further investigations on the conditions inside the hen house rather than in the free-range.