Animal Molecular Breeding 2016, Vol.6, No.3, 1-5
2
2.1 Replacement of locally adapted breeds by exotic commercial breeds
There has been a tremendous decline in the number of indigenous poultry breeds over the last three decades. This
is occasioned by their replacement with modern commercial breeds in small farms and in the villages. These
indigenous breeds consist of locally adapted breeds which have gone through millennia of years of evolution.
2.2 Global amalgamation of primary breeding companies
A lot of closures, mergers and buy over of many poultry breeding companies have been witnessed globally since
the past decade. These are due to poor profit margins and inclement business environments. The resultant effect is
an overall decrease in total number of purelines by these multinationals marketing breeding stocks globally.
Thiyagasundaram (2013) noted that only five major poultry breeding companies supply almost all the egg layer
stocks globally. The author affirmed that in the broiler market, only six major primary breeders holding 30 to 40
pure lines control and supply 400 billion broilers globally. These stocks are designed and genetically selected over
many generations for economic traits of growth and production. They require specialized management, nutrition,
disease prevention and environmental conditions for optimal performance to ensure profitability. They lack
adequate heterozygosity to sustain evolutionary changes and adaptation because of uniformity of the genotypic
base.
2.3 Consumers preference for certain varieties and breeds
Owing to the consumers preference and demand for certain specifications in poultry products, there has been an
intense genetic selection over many decades in favour of the preferred breeds and lines. This leads to loss of
genetic variation in industrial stocks. Stocks with less genetic variability find it difficult to cope with most
environmental challenges like disease outbreaks and climatic change. Success in commercial animal breeding is
dependent on the genetic composition of the populations and reduced variability results in a limited flexibility to
reach new breeding goals (Weigend et al., 2013; Crawford, 1990).
2.4 Uncontrolled crossbreeding of the village chicken
In developing countries village chickens represent a diverse gene pool that comprise unique genetic features. Due
to their development in a given environment they are better adapted to survive under harsh environmental and
management conditions. Crossbreeding has been utilized extensively in the developing countries to improve the
productivity of the indigenous livestock. But uncontrolled crossbreeding is one of the major causes of loss of
genetic diversity especially among the rural poultry species and breeds. This menace may lead to a replacement of
local genotypes with those of commercial hybrids, which have a higher production potential based on high
nutrient requirements but are not selected for survival in such an environment (Weigend et al., 2013).
3 Relevance of Conservation of Poultry Genetic Diversity
The relevance of genetic diversity conservation in poultry production cannot be overemphasized because genes
play a major role in formation of breeds and species. Genetic resources are the building blocks for poultry
development. It enables farmers and breeders to respond to changing environmental conditions and to meet
consumers demand. Conservation of genetic diversity helps to reduce the dependency on external inputs as the
improvement of indigenous breeds is encouraged.
Conservation helps to preserve desirable traits and produce birds with high quality grades. It also encourages
natural selection of only the fittest individuals which are better able to cope with diverse environmental challenges.
Wikipedia (2013) noted that if a population of a species has a very diverse gene pool, then there will be more
variability in the traits of the individuals in that population and consequently more traits for natural selection to act
upon to select the fittest individuals to survive.
Genetic diversity and biodiversity are dependent upon each other. Diversity within a species is necessary to
maintain diversity among species, and vice versa (NSF, 2006). The authors argued that if one type is removed
from the system, the cycle can break down, and the community becomes dominated by a single species. The
National Biological Information Infrastructure (2008) asserted that the interdependency between genetic and
