Feed selection on dry rangelands in southwestern Madagascar: Implications for ruminant nutrition in view of ecological and social challenge

- Investigation of natural forage use in a highly variable environment in Madagascar.
- Forage quality and quantity substantially decrease during the long dry season.
- Locally important supplementary forage species can bridge dry season shortages.
- Holistic pastoral regime threatened by increasing climate variability and conflicts.

Locally appropriate strategies to improve livestock feeding in situations of feed scarcity are needed when external factors such as increasing climate variability and conflicts constrain traditional pastoral management. To identify such strategies, we analyzed the use of natural forage by cattle and goats in southwestern Madagascar against seasonal variability and spatial disparity in feed quality and quantity. The feeding behavior of 12 herds of each species was observed and the animals' preference for specific plants recorded. Samples of forage plants and of livestock feces were analyzed for nutrient concentration; diet digestibility was derived from fecal nitrogen concentration.Across the research area, livestock fed on 133 plant species of which 12 were of major importance. Nutritional quality of consumed plants substantially decreased throughout the dry season. In this situation, Euphorbia stenoclada and Opuntia monacantha were important supplementary species to bridge feed shortages. The results conform to a holistic pastoral regime in which livestock keepers try to optimize the use of locally available feed resources. However, amplification of fluctuations in rainfall and increasing insecurity threaten the balance between forage availability and livestock requirements and therefore necessitate retaliatory actions that can sustain the local livestock system without compromising the region's unique biodiversity.