Abstract:
Sheep play an important role in the livelihood of most people in the tropics, mainly through meat production (Gatenby, 1986 ; Kiwuwa, 1992), and have potential for greater contribution through better management and genetic improvement. Traditional minimal-input systems with indigenous animal breeds predominate (Gatenby, 1986 ; de Leeuw et al., 1991). Various bottlenecks towards effective breeding programs exist, e.g. small flock sizes, lack of systematic animal identification, inadequate
animal performance and pedigree recording, and organizational short
comings (Kiwuwa, 1992). However, use of local breeds that are adapted to
their harsh conditions and low level of management should be encouraged as exotic breeds often fail to survive or even reproduce (Turner, 1985). Nucleus breeding schemes have been proposed as
a good strategy for genetic improvement of livestock in developing countries (Hodges, 1990). However, a crucial point is adequate interact
ion between nucleus and commercial sectors. One other option is to run
a co-operative (‘ram circle’) breeding program among some larger commercial groups. The aim of this study is to compare, through
simulation, different sheep nucleus breeding schemes interacting with
commercial flocks.