STM Article Repository

Genetic selection has greatly increased body conformation and rate of growth in poultry birds.
However, this progress has been speculated to come at the cost of robustness, where the animals are
not able to maintain production in the presence of heat, with a much felt impact on genetically
selected progeny compared to non-selected. Growth in meat-type chickens is the most economically
important trait, but under heat stress, birds divert dietary resources meant for growth and
development into homeostatic adjustments. Genetic adaptation refers to the heritable traits of animal
characteristics that favor the survival of such populations (Abdul Niyas et al., 2015). Adaptation traits
are usually characterized by low heritability. Such adaptations enable individual organism to
successfully adapt to certain features inherent in a habitat which may be due to behavioral,
morphological, physiological as well as genetic bases (Yasha et al., 2017). Genetic variation in a
population provides flexibility to adjust or adapt to the changing environment and it is crucial for the
survival of the population over a given period of time. According to some, the genetic basis of heat
adaptation in poultry is poorly understood. Evidence from different researchers have indicated that the
role of genetics in determining an individual’s capability to adapt to vulnerable regions of heat stress
predominance is very complicated.