-Red deer play a major role in shaping forest vegetation, and a better understanding of their selectivity is needed in order to provide a basis for deer habitat and population management. In order to measure deer selectivity, information is required on both the use and availability of different food items at the feeding site scale, which has often been proven difficult to achieve with wild animals. In this study, we introduced three hinds for five days in each season into a 1 ha paddock established on a mixed forest edge. We analysed the relationship between the choices made on the first day in the paddock and the available vegetation, and calculated selectivity indexes (S i ). The hinds were highly selective, with on average 82% of their diet made of preferred species. Selected and avoided species varied between seasons according to plant phenology, except for conifers and ferns, which were always avoided. The intermediate feeding style of the Red Deer was confirmed, with concentrate foods (broad-leaved trees and seedlings, shrubs, forbs and legumes) being selected from the spring to the autumn, followed by a switch to grass during the winter. The hinds selected grass in the winter since it was a highly available and relatively "high quality" forage at that time. The net intake of digestible energy was probably increased by eating grass than by searching for the higher quality but scarce forbs. This resulted in the dry matter intake maximisation hypothesis being valid during the winter, but rejected for the other seasons. The highly selective consumption of broadleaved seedlings throughout the growing season suggests a high risk of damage to these seedlings at a year-round deer density of about 15 hinds per km². Cervus elaphus / diet selection / Jacobs index / seasonal variations / vegetation sampling techniqueRésumé -Variations saisonnières de la sélectivité du cerf élaphe en milieu forestier. Mieux connaître la sélectivité alimentaire du cerf élaphe est nécessaire pour pouvoir gérer ses populations et limiter ses dégâts en milieu forestier. Ceci nécessite de mesurer simultanément ses choix et les disponibilités alimentaires, ce qui est particulièrement difficile en milieu naturel. Ici, nous avons observé les choix alimentaires de trois biches dans un enclos d'un hectare établi en lisière de forêt, que nous avions préalablement caractérisé et cartographié. Nous rapportons les choix réalisés à chaque saison lors de la première journée dans l'enclos, et calculons pour chaque espèce un indice de sélection (S i ) en reliant le prélèvement des animaux aux disponibilités alimentaires. Les biches ont été très sélectives avec en moyenne 82 % de leur régime composé d'espèces préférées. Elles ont sélectionné des espèces différentes au cours de l'année, seuls les conifères et les fougères étant systématiquement évités. La classification du cerf parmi les « intermediate feeders » a été vérifiée ici, puisque les biches ont, du printemps à l'automne, sélectionné les feuillus, les ligneux bas à feuilles caduques et ...
Forage legumes that contain secondary compounds are considered to be less susceptible to proteolysis than other legumes, with improved silage quality and possibly improved animal performance. This was investigated feeding five groups of growing lambs for 10 weeks, five silages composed of pure timothy (T; Phleum pratense), mixtures of T with red clover (Trifolium pratense; T‐RC, 50/50 on DM basis), sainfoin (Onobrychis viciifolia; T‐SF), or both (T‐RC‐SF, 50/25/25), or a mixture of the two legumes (RC‐SF). Including SF and/or RC in silages improved silage fermentation as shown by higher lactic acid and lower soluble N and NH3 contents than in T silage. Voluntary intakes were higher with all the RC‐containing silages than with T and T‐SF. The T‐SF silage had the lowest, and RC‐containing silages the highest average values for daily gain, feed conversion efficiency, live weight and carcass weight. The differing effects of these silages cannot be totally explained by differences in their nutritive value and so may be due to their bioactive compounds impacting differently on feeding motivation and digestive efficiency. These results suggest that including RC in silages is a promising strategy to combine improved animal performance with reduced environmental pressure.
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