ABSTRACT
Profitability of livestock production may be affected -- directly or indirectly -- by world-level economic and political factors. At the national level, policies on prices, trade, and credit are formulated and political and economic interventions to livestock production are commonly made. The herd is the basic production unit consisting of three components: the breeding male, the breeding female, and the nonbreeding animals. Agricultural systems involving livestock were classified according to predominant agricultural activities. Net Merit of livestock production must be evaluated in the context of the overall agricultural food and fiber system. Any of the components of livestock production systems -- resource inputs, production processes, and product outputs -- can be a constraint to system productivity. Strategies for genetic improvement will be used to illustrate design of interventions to resolve constraints and improve productivity. The systems approach to genetic improvement calls for analysis of needs, for fitting genotypes to production environment, and for anticipating future market requirements.
