Seasonal dynamic of herbaceous fodder production in the Sahelian pastures used by domestic ruminants

Abstract

Natural pastures which constitute the main feed resources for ruminant animals are submitted to high pressure due to combine effects of climate changes and extensive exploitation. This study was conducted in the Sahelian zone of Burkina Faso with the aim to estimate the exploitation strategies of forages resources and to evaluate the seasonal dynamic of herbaceous production in pastures. After an inventory of the pasture types and their characterisation, regular measurements of the herbaceous production were made from October to January. Subsequently, a monitoring of herds of cattle, sheep and goats was done to appreciate resources use. The results showed five types of pastures (including fields) in the area, which differ by the flora diversity and the herbaceous production. The pasture of lowland presented high potentialities, and low production was recorded in tiger bush pasture. The herds exploited these pastures strategically to benefit from resources available at a good time, and to move of cultivated fields. From the maximum fodder production of 4271 kg MS/ha, 3061 kg MS/ha, 2890 kg MS/ha and 1251 kg MS/ha observed in lowland, shrubby steppe, woody steppe and tiger bush pastures respectively, the herbaceous production decreased quickly depending on pasture types and the grazing pattern in the rainy season. The disappearance rate of biomass varied from 77.6% in hollow pasture in November, to 83% in woody steppes pasture in December. These results suggested adaptation strategies by farmers and in animals feeding behaviour to prevent animals from starvation in dry season the area. Keywords: herbaceous production, herd monitoring, pasture, seasonal dynamic.