HANS-DIETER HESS, TASSILO TIEMANN, MICHAEL KREUZER
Swiss Federal Institute of Technology (ETH), Swiss Centre for International Agriculture (ZIL), Institute of Animal Sciences (INW), Switzerland
Ruminants play an important role as assets and sources of high quality food and income for rural populations in the developing world. Ruminant productivity is usually low due to inadequate nutrition (i.e. protein deficiency). Promising forage species, mainly legumes, have been identified to overcome these limitations. Many of these legume species contain tannins that could be either advantageous or disadvantageous in terms of feed efficiency and metabolizable protein supply to the animal. The overall aim of this project is to develop efficient feeding systems based on tanniniferous shrub and tree legumes in order to improve livestock productivity and to alleviate poverty of smallholders in the tropics. This will by achieved through (i) studying the effect of plant nutritional status on the accumulation of condensed tannins in legumes, and the influence of these tannins in ruminant nutrition and the nitrogen fertiliser value of animal excreta for plants, and (ii) designing optimal feeding strategies based on the use of mixtures of tropical forage legumes with contrasting tannin contents to overcome the limitations of ruminant diets in protein supply. At the end of the project period, the potential impact of the obtained results will be assessed by an ex-ante economic analysis at farm level and at ecoregional levels. The outcomes of this work should provide the necessary background information for better feeding practices based on tanniniferous legumes. By dissemination and adaptation of the project outputs with farmers, the new management and feeding strategies will improve the nutrient supply for the ruminant animals, which will increase feed use efficiency and animal productivity in low-input livestock systems. This, in turn, will increase competitiveness and income of the farm households.
Keywords: Grass, legumes, livestock, protein, tannins