Importance of Genetics
Do we use natural or artificial selection in Ag?
Artificial
What is a phenotype? Give an example:
Observable, physical characteristics
The percentage a trait is affected by the animal’s GENETIC information is called what?
Heritability
What is feed efficiency? Explain it!
Weight gain vs feed intake
What's an allele? How many are inherited from each parent?
A form of a gene found in pairs
Located on chromosomes
1 allele inherited from each parent
What is artificial selection?
Humans control which animals reproduce based on presence of desirable characteristics.
What is a genotype? Give an example:
An organism’s genetic code represented by a pattern of letters.
What is the range of heritability factors? What's considered high?
0.0-1.0
<0.5 is low
>0.5 is high (or equal to)
Should every animal pass on its genetics? What happens if you don't want it to pass on its genetics?
In the pet industry, these animals are sterilized (spayed or neutered)
In the livestock industry, they are usually raised for terminal markets
What is a dominant allele?
Represented by CAPITAL letters
This trait is the one expressed
What is Natural Selection?
“Survival of the Fittest”
If the animal has characteristics to survive, it reproduces
No human intervention
What is heredity?
It is the POTENTIAL an animal has to show specific traits or performance due to its genetic information.
Give an example in cattle, sheep, and swine a trait with a high heritibility factor.
Cattle: Height, Ribeye area
Sheep: Wool face cover, Loineye area, Carcass fat
Swine: Backfat Thickness, Loineye area, Length, and Chilled carcass weight
What are some genetic strengths a dairy cow farmer is gonna look for?
Milk Production
Milk Components (Butterfat & Protein)
Longevity (Calves produced & lactations completed)
What is a recessive allele?
Represented by lowercase letters
Only expressed if both alleles are recessive
Why do we use artificial selection in ag?
More ability to control desired characteristics.
What is environment?
The EXTERNAL conditions that affect the traits and performance of an animal
Breeders identify genetic strengths based upon their goals. What are some examples?
Meat production, Temperament, Coat Color
What are some genetic strengths a horse breeder may look for?
Structure & Size
Coat Color
Performance Abilities
Temperament
What is the difference between heterozygous and homozygous?
Homozygous:
Both alleles are the SAME
(BB) = Homozygous dominant
(bb) = Homozygous Recessive
Heterozygous:
Different alleles for the same trait
(Bb)
Why should ag products be higher quality and more consistent?
CONSUMERS want high quality and consistency when they SPEND THEIR MONEY. Regardless of what avenue the farmer takes to sell, in the long run the only way a farmer makes money is if the consumer buys their product!
Environment + Genetics =
Traits and Performance
Would a beef cattle farmer care about the same traits if they had a farm to table operation vs if they had a cattle calf operation? Yes or no and explain. BE DETAILED!
NO - a farm to table farmer is gonna focus more on carcass traits like frame size and rib eye area, a cattle calf farmer is gonna focus more on growth rates, coat color, etc.
What are some genetic strengths a sheep breeder may look for?
Multiple Births (# lambs per ewe)
Wool Quality
Growth
What is the difference between a qualitative trait and a quantitative trait? Which one can you determine the probability of having with a punnet square?
A qualitative trait is a phenotype (something you can observe). A quantitative trait is something that can be measured. Qualitative traits probability can be determined by punnet squares.