Agriculture Reference
In-Depth Information
4
Breeding and Genetics
J.N.B. Shrestha , PhD and G.H. Crow , PhD
KEY TERMS
Mendelian genetics—the study of underlying principles governing inheritance of morphological characters according
to the laws of Segregation and Independent Assortment.
Population genetics—the area of genetics that deals with genetic composition of biological populations and patterns
of genetic changes as a result of evolution and natural selection.
Quantitative genetics—the study of genetic principles governing inheritance of continuous measures of performance
determined by many genes and an environmental component.
Breeding—application of quantitative genetic principles and skillful practice in selection and mating systems to
improve the effi ciency of animal production.
Selection—disproportionate contribution of the parents to their offspring as a result of differences in fi tness.
Crossbreeding—crossing of two or more divergent breeds to produce offspring.
OBJECTIVES
By completing this chapter, the reader will acquire knowledge on:
The underlying principles governing inheritance of morphological characteristics and production performance from
parents to their offspring
How forces of evolution and natural selection cause gene frequency changes in biological populations
That quantitative traits in an individual follow an extension of the basic Mendelian principles of inheritance
The role of genetics and environment in determining the phenotype of the individual
Many specialized goat breeds that remain in the world have potential genetic merit to respond to current and future
market requirements
The inherent potential for performance transmitted from parents to their offspring is additive for many traits of
economic importance
The role of nonadditive genetic variation associated with the crossing of complementary breeds
That real improvement of production effi ciency can be achieved with the application of quantitative genetic prin-
ciples to exploit biological potential
The socioeconomic values, fi scal constraints, religious rituals, responsiveness to indigenous knowledge and tradi-
tional skills in improving production effi ciency of goats
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