lOMoARcPSD|2392027
Wondershare
Verwijder Watermerk
PDFelement
Week 1
Ch1: Introduction
Animal breeding -> selecting animals to be parents of next generation
Improve genetic level of population
Maintain genetic diversity
Involves:
- Selective breeding (domestic) animals
- Intention to improve desirable qualities next generation
Selective breeding => only using animals that passed quality criterion
Traits -> something you can observe on animals
Everything you can measure
Heritable
Variation in phenotype is linked to variation in DNA
Application of animal breeding:
o Feeding world in sustainable way with genetic improvement & improved management
o More than ½ of improvement in milk production is due to genetics
Achieving genetic improvement
Artificial selection of best animals
Next generation better than current
Improvement across generations is cumulative (increasing more and more)
Inbreeding
o Number of available animals limited
o Not necessarily bad, if not too strong
o Mating of relatives
- Loss of genetic variation
- Inbreeding depression -> lower production levels
Crossbreeding
o Opposite of inbreeding
o Hybrid vigour or heterosis
o Crossbred is doing better than average of parents
Phenotype depends on:
o Genetic background
o External circumstances (e.g. nutrition)
Gedownload door Michou Weimar ()
, lOMoARcPSD|2392027
Wondershare
Verwijder Watermerk
PDFelement
Natural selection
o Environment determines survival & reproductive success
o Animal breeding = artificial selection + natural selection
Domestication
1st domesticated -> dogs
Perquisites:
1. Naturally calm
2. Able to adapt to type of feed offered by humans
3. Recognize human as superior
Ch2 Breeding goal & breeding program (step 1&2)
Breeding program steps
Breeding program = organized structure set
up in order to realize desired genetic
improvement of population
Production system (1)
Before breeding:
- Circumstances animals are kept in = production system
- Direction in which you want to go = breeding goal (determined by production system)
Describing production system:
- Geographical location -> climate
- Purpose of animal -> production, companion, sport, working, saving
- Animal species & breed (dog -> border collie)
Breeding goal (2)
1. Traits you want to improve/ combination of specific traits
2. Desired direction of change over generations
3. Relative emphasis on each trait
Defining breeding goal:
o Determine traits -> breeding value
Gedownload door Michou Weimar ()
, lOMoARcPSD|2392027
Wondershare
Verwijder Watermerk
PDFelement
- Economic
- Non-economic
o Weigh traits into single criterion
o Goal should be directed to future (5yrs)!
- No milk quota, phosphate system
- Ban on cages and castration
Breeding value => measure of genetic merit of animal
o Indication of performance offspring
o Example:
- Bull with breeding value of +1000kg milk
- Daughters expected to produce +500kg milk (½) than daughters average bull
Breeding goal as single criterion
o H=v 1 A 1+ v 2 A 2+ …
- H = breeding goal
- v1 = value trait 1
v2 = value trait 2
- A1 = breeding value trait 1 (measured)
- A2 = breeding value trait 2
E.g Inet = 0.3 x Akg lactose + 2.1 x Akg fat + 4.1 x Akg protein
o Usually > 1 trait
o Inclusion of traits depends on importance
o Breeding goals expressed as single value -> easier to rank individuals
o H = true breeding value -> can not be measured, has to be estimated
H = aggregate genotype
Economic values
Economic value => expected net profit of improving trait with 1 unit (e.g. kg)
Breeding goal based on profit model of production system
Economic value = revenues (profit) – costs (e.g. feed)
Expected net profit = economic value => (partial) derivative profit function
- Revenues = 2.2 euro
Feed costs = 1.0 euro
Other costs = 0.1 euro
- Profit function: p(x) = 2.2x – 1.0x – 0.1x = 1.1x
- Economic value = 1.1
Non-economic values
o Ethical aspects
- Welfare
Gedownload door Michou Weimar ()
Wondershare
Verwijder Watermerk
PDFelement
Week 1
Ch1: Introduction
Animal breeding -> selecting animals to be parents of next generation
Improve genetic level of population
Maintain genetic diversity
Involves:
- Selective breeding (domestic) animals
- Intention to improve desirable qualities next generation
Selective breeding => only using animals that passed quality criterion
Traits -> something you can observe on animals
Everything you can measure
Heritable
Variation in phenotype is linked to variation in DNA
Application of animal breeding:
o Feeding world in sustainable way with genetic improvement & improved management
o More than ½ of improvement in milk production is due to genetics
Achieving genetic improvement
Artificial selection of best animals
Next generation better than current
Improvement across generations is cumulative (increasing more and more)
Inbreeding
o Number of available animals limited
o Not necessarily bad, if not too strong
o Mating of relatives
- Loss of genetic variation
- Inbreeding depression -> lower production levels
Crossbreeding
o Opposite of inbreeding
o Hybrid vigour or heterosis
o Crossbred is doing better than average of parents
Phenotype depends on:
o Genetic background
o External circumstances (e.g. nutrition)
Gedownload door Michou Weimar ()
, lOMoARcPSD|2392027
Wondershare
Verwijder Watermerk
PDFelement
Natural selection
o Environment determines survival & reproductive success
o Animal breeding = artificial selection + natural selection
Domestication
1st domesticated -> dogs
Perquisites:
1. Naturally calm
2. Able to adapt to type of feed offered by humans
3. Recognize human as superior
Ch2 Breeding goal & breeding program (step 1&2)
Breeding program steps
Breeding program = organized structure set
up in order to realize desired genetic
improvement of population
Production system (1)
Before breeding:
- Circumstances animals are kept in = production system
- Direction in which you want to go = breeding goal (determined by production system)
Describing production system:
- Geographical location -> climate
- Purpose of animal -> production, companion, sport, working, saving
- Animal species & breed (dog -> border collie)
Breeding goal (2)
1. Traits you want to improve/ combination of specific traits
2. Desired direction of change over generations
3. Relative emphasis on each trait
Defining breeding goal:
o Determine traits -> breeding value
Gedownload door Michou Weimar ()
, lOMoARcPSD|2392027
Wondershare
Verwijder Watermerk
PDFelement
- Economic
- Non-economic
o Weigh traits into single criterion
o Goal should be directed to future (5yrs)!
- No milk quota, phosphate system
- Ban on cages and castration
Breeding value => measure of genetic merit of animal
o Indication of performance offspring
o Example:
- Bull with breeding value of +1000kg milk
- Daughters expected to produce +500kg milk (½) than daughters average bull
Breeding goal as single criterion
o H=v 1 A 1+ v 2 A 2+ …
- H = breeding goal
- v1 = value trait 1
v2 = value trait 2
- A1 = breeding value trait 1 (measured)
- A2 = breeding value trait 2
E.g Inet = 0.3 x Akg lactose + 2.1 x Akg fat + 4.1 x Akg protein
o Usually > 1 trait
o Inclusion of traits depends on importance
o Breeding goals expressed as single value -> easier to rank individuals
o H = true breeding value -> can not be measured, has to be estimated
H = aggregate genotype
Economic values
Economic value => expected net profit of improving trait with 1 unit (e.g. kg)
Breeding goal based on profit model of production system
Economic value = revenues (profit) – costs (e.g. feed)
Expected net profit = economic value => (partial) derivative profit function
- Revenues = 2.2 euro
Feed costs = 1.0 euro
Other costs = 0.1 euro
- Profit function: p(x) = 2.2x – 1.0x – 0.1x = 1.1x
- Economic value = 1.1
Non-economic values
o Ethical aspects
- Welfare
Gedownload door Michou Weimar ()
