Review of undernutrition in smallholder ruminant production systems in the tropics

Developing countries continue to face the challenge of increasing poverty and depleting asset base of their predominantly rural populations. In sub-Saharan Africa (SSA) alone, over 70% of the population now live below the poverty line, and in South Asia the number of poor people exceeds 500 million. More than 160 million children worldwide are protein malnourished. Over two-thirds of the world's 1.3 billion poor live in rural areas and rely on agriculture for a significant part of their livelihoods. Livestock are important assets to the rural poor and play a critical role in both the sustainability and intensification of agricultural productivity in most farming systems. They provide food and essential nutrients for cognitive growth of children and the general welfare of humans. Their manure helps maintain soil fertility and they contribute to the overall farming enterprise in terms of income and employment. Livestock also provide poor farmers with a flexible reserve and access to markets. In many rural societies poor women derive their income from livestock keeping. The objective of this review paper was to describe the major nutritional constraints to ruminant meat and milk production systems in the developing world and explore ways of overcoming undernutrition in the tropics. Issues addressed in this review include causes of undernutrition and environmental implications, adaptation by the ruminants to it, manipulative strategies to cope with feed scarcity in smallholder ruminant production systems and modelling of undernutrition in ruminants. This review paper has evolved as a working paper over the last few years, and represents the contributions of many staff members of the International Livestock Research Institute (ILRI) and their collaborators, which are acknowledged in this publication