genetics 2: population genetics in animal breeding Flashcards
what are the benefits of using genetics for animal improvement
genetic improvement takes time and a long term view is required
- assist in meeting market requirements
- improve overall productivity and profitability
- improve specific traits of an animal including growth rate, carcass yield, fleece weight, fibre diameter, variation in birth weights and disease resistance
what are the sources for genetic variation
genotypes coding for phenotype come from
- mutations (changes in DNA)
- gene flow (movement of genes from one population to another)
- sex (introduction of new gene combinations into a population)
what is gene flow
within a population: it can introduce or reintroduce alleles to a population, increasing the genetic variation of that population
across populations: by moving genes around it can make distinct populations genetically similar to one another
what is genotype frequency
the proportions of animals with each genotype
what is a qualitative trait
characterised by segregation in classical mendelial ratios, purely genetic
- coat colour
- absence of horns
scrapie is a disorder in which gene
Prp gene
canine haemophilia B is a genetic disorder affecting
factor IX mutation
what is a qualitative trait
also referred to as continuous traits (growth rate or milk yield)
what is a phenotype
an observed category or measurable level of performance for a trait in an individual
define genotype
the genetic make up of an individual
what is a germ line mutation
a mutation in the gametes - will be passed on generation to generation. particularly important when considering breeding
list environmental factors affecting genetics
- temperature
- photoperiod
- housing
- bedding
- medication
- hydration
- nutrition
- maternal care
- intrauterine conditions
- eggs develop in grandmaternal generation
