Seasonal dynamic of pasture production in the Sahelian rangeland of Burkina Faso

Rangelands are the main feed resources for ruminants although they are being excessively exploited due to combined effects of climate changes and extensive grazing. This study was conducted in the Sahelian zone of Burkina Faso with the aim to estimate the exploitation modes of forages resources and evaluate the seasonal dynamic of herbaceous pasture production. After an identification of the pasture types and their characterisation, periodical measurements of pasture production were made from October to January. Consecutively, cattle herds, sheep and goat flocks were observed to study resources use. The results showed five types of rangeland (plus cropped fields), which differ by the plant diversity and pasture production. The lowland rangeland has shown high potentialities, whilst low production was recorded in "tiger" bush rangeland. The herds grazing these areas were moved from the cultivated fields. The highest pasture production measured in lowland, shrubby steppe, woody steppe and tiger bush rangeland (respectively 4271 kg DM/ha, 3061 kg DM/ha, 2890 kg DM/ha and 1251 kg DM/ha) decreased quickly depending on rangeland types and the grazing pattern in the rainy season. The rate of decrease in biomass varied from 77.6% in lowland pasture in November, to 83% in woody steppes pasture in December. These results suggested adaptation strategies by herders and in animals feeding behaviour to prevent animals from starvation in dry season in the area.