1. Chapter 1: Introduction  Danish production- and family animal population  Evolution and breeding  Phenotype, genotype and environmental heritability  Quantitative and qualitative traits

2. Danish production- and family animal population

4. Evolution – Natural selection  Survival of the fittest (Darwin, 1859)  Best adapted individuals have better chances of surviving and breeding offspring  Natural selection  Environmental conditions decide which individuals will be best adapted

5. Evolutionary theory made simple !

6. Breeding – man made selection (evolution)  Definition of the goals for breeding: the best animals are selected  Typically the goals for the breeding are a combination of different traits, which are important in the production  The population average for the breeding goals can be changed in a favourable direction

7. Breeding - man made selection  Definition of the goals for breeding: the best animals are selected  Typically the goals for the breeding are a combination of different traits, which are important in the production  The population average for the breeding goals can be changed in a favourable direction

8. Selection changes in fat % in dairy cattle

9. Phenotype, genotype and environment Phenotype = genotype + environment P = G + E Interaction between genetics and environmental factors P = f(G,E)

10. Phenotype  What can be measured, weighted or registered in any way  The trait can be recorded  For instance kg gain in slaughter pigs, kg milk in cows or exterior in horses

11. Genotype  Alleles on different loci  Half the genes are transferred to the offspring  The genotype is part of the phenotype, which can be found again in the offspring  Codes for the protein synthesis  The genotype cannot be observed  The genotype of an offspring will generally be the average of the parents’ phenotypes

12. The influence of polygenetic inheritance on genetic variation

13. The environmental influence on the phenotype  Fodder, nutrition, substrate  Temperature  Draft  Humidity  Stress  Management strategy

14. Phenotype, genotype and environment P = G + E

15. Heritability Relationship between weight of mother and offspring by inbreeding and outbreeding

16. Regression of height of offspring on height of parent

17. Quantitative and qualitative traits

18. Genetic polymorfy in a pig family

19. The terms gene, locus and allele Old terminology When in the Labrador Retriever a gene for yellow coat colour is mentioned it both points at a locus and an allele. Because a locus or a gene was identified by the deviating phenotype yellow. New terminology A recessive allele for yellow coat colour in the extention locus