Goat foraging activities in rangeland in high catchment zone of Mandrare, Southern Madagascar

The edible forage resources were studied with Ruminants behaviour in the High Bassin zone of Mandrare in Southern Madagascar. Analysing the floristic components and goat foraging behaviour allowed determination of nutritive value, bite rate and preference ratio in rangelands. Sampled areas were monitored to record the floristic formation within calculated parameters such as species quality index, pastoral value and preference ratio. Using six selected adult goats within mix ruminants herd (cattle, sheep and goat), foraging behaviours were analyzed by sequential recording during two periods (early dry season and later dry season). Using Principal Component Analysis, four pasturelands groups were distinguished with dominant browse species such as Acacia farnesiana, Poupartia caffra, Kigelianthe madagascariensis and Rhigozum madagascariense. Floristic composition were characterized by lower densities with 392  142 plants.ha-1; with higher heterogeneity (1.04  0.07) and Shannon – Weaver Index (0.43 ± 0.15; p < 0.05). Most of 43 identified species were available to animals with a higher nutritive value. Acacia farnesiana rangeland was dominated by shrubs with higher nutritive value, resulting in a higher bite rate and pastoral value, and was overgrazed. The relationships between phytosociology and nutritional parameters allow for improvement of range management and native rangeland restoration with autochthonous species.