Botanical composition of herbage intake of free-range laying hens determined by microhistological analysis of faeces

To understand the contribution by forage in the nutrition of free-range laying hens, there is a need for more information about the botanical composition of herbage intake from range areas. The effect of different forage crops and feed types on the botanical composition of herbage intake in free-range laying hens was investigated using the microhistological methodology. In this method, cellular characteristics from leaf epidermis found in faeces are used for species or genus identification. The experiment was carried out with 12 flocks of 20 laying hens in a 2x2 factorial design with two different forage crops and two types of supplementary feed (typical layer diet for organic layers versus whole wheat grain) with three replications. The forage crops consisted of a well-established grass/clover (Lolium perenne and Trifolium repens) pasture or a mixture of forbs (Fagopyrum esculentum, Phacelia tanacetifolia and Linum usitatissimum). On the grass/glover pasture negative selectivity indices were found for Trifolium repens and positive selectivity indices for Elytriga repens for both types of supplementary feed. In the forage crops sown with the mixed forbs positive selectivity indices were found for the species of plants near the ground such as Elytriga repens, Lolium perenne and Trifolium repens. Contrary to this negative selectivity indices were seen for the taller species of plants Fagopyrum esculentum and Phacelia tanacetifolia. Our results indicate that hens offered the layer diet had a higher preference for Trifolium repens than the wheat-fed hens, whereas the wheat-fed hens had a higher preference for Elytriga repens.