| Agostino Sevi, Donato Casamassima, and Antonio Muscio |
| Sevi and Muscio are researcher and professor with Institute of Food Production and Preparation. Agriculture Faculty of Foggia. University of Bari. Via Napoli, 25. 71100 Foggia (Italy). Casamassima is a professor with Department of Animal, Vegetable and Environment Science. University of Molise. Via De Sanctis. 86100 Campobasso (Italy) |
Abstract |
| Two grazing trials were conducted during early winter (January 1996) and spring (April 1996) to evaluate the effect of group size on grazing efficiency and behaviour of sheep. Three treatments were tested, large (LG), medium (MG) and small group size (SG), with 2 replicates for each treatment of 12, 9, and 6 ewes, respectively. Groups were homogeneous for age and weight. Paddock size furnished 10 m2 per sheep per day. Group size did not affect grazing efficiency and herbage intake in the winter, but in the spring, when herbage mass was more plentiful, the ewes in the small groups grazed shorter, had a lower herbage intake and a less efficient use of forage. Consequently, the sheep in the small groups gained less weight than those in the large groups in spring. Neither group size nor seasonal changes in forage quantity or quality influenced sheep selectivity. These results suggest that the choice of a proper flock size at pasture can play a major role in optimizing grazing efficiency in sheep, especially when feeding is largely based on grazing, as generally occurs in countries of the Mediterranean basin in spring. Under the conditions of this study, our results indicate that a flock size of more than 6 sheep should be used for studies on sheep grazing behaviour. |
| Key Words: diet quality, grazing management, intake |