Ansc 3500 Breeding exam 1

What is animal breeding?

the process of selective breeding of domestic animals to improve desirable (and heritable) qualities in the next generation

animal genetics

the study of principles of inheritance in animals

empirical principles

selection of friendly animals and behavioral traita

Sir Robert Bakewell

Founder of Animal Breeding. Breed the best to best and hope for the best. progeny testing to evaluate the genetic potentials of young sires

Gregor Mendel

Traits are controlled by factors (genes). The father of Genetics

The founders of Theoretical population genetics

Robert A Fisher, Sewall Wright, J.B.S Haldane

Jay L. Lush

Father of Modern Animal Breeding. Genetics and Statistics

L.N Hazel

Selection Index Theory

Charles R. Henderson

BLUP Animal Model. and Breeding value

Breeding Value

the value of an individual as a genetic parent

Branches of Genetics

Mendelian, population, Quantitative

Mendelian

study the principles of transmission of genetic material across generations. Laws of inheritance

Population

study of genetic makeup of populations, focusing on allele and genotype frequencies, and how these change over time.

quantitative

the study of how multiple genes are environmental factors influence traits

Selection

the process that determines which individuals become parents, how many offspring they produce, and how long they remain in the breeding population

Let individuals with the best set of genes reproduce so that the next generation

ON AVERAGE, has more desirable genes than the current generation

Natural selection

process that occurs naturally without human interference. traits acquired increase survival chances

Artificial selection/ selective breeding

replacement selection or culling. humans select the desired traits. new traits not always beneficial or improve the survival of the species.

mating

the process which determines which (selected) males will be bred to which (selected) females

Change in population performance

the gain through genetic improvement is permanent although it is slow

Breeding goal

the specification of the traits to be improved including the emphasis given to each trait

trait

any observable or measurable characteristic . EX. coat color, litter size, yearling weight

Phenotype

Any observed or measured level of performance for a trait EX. 10 piglets, horned or polled, 850 Ib weight, black coat color

Breeding program

a program aiming at defined breeding objectives for the production of the next generation of animals

breeding program characteristics

trait under selection is heritable; animals have different genetic backgrounds; the direction of selection is defined by humans

Breeding program success

a shift in the population’s average across generations. the cumulative result of multiple generations of selection

Closed nucleus

use animals within the nucleus population for the genetic improvement, without introducing external animals

open nucleus

allows the introduction of genetically superior animals from the lower tiers or external populations into the nucleus

Breeding equation

P= G+E

p

any observed category or measured level of performance for a trait

G

genetic makeup- complete set of genetic material

gene by environment interation

refer tot he difference in the average performance of two different genotypes is different in two different environements

Breeding equation including gene by environment interation

P= G+ E + (G*E)

the genotype can differ in both their

genetic potential for the character being evaluated and in their level of adaptation to one or both of the environments

genetic potential

the highest level of performance that the particular genetic group could achieve in the absence of environmental stress and all their nutritional requirements were met.

The level of adaptation of the two different genotypes in the two different environments determine

how much of their genetic potential can actually be achieved in the two different environments