Applied Genetics in Cattle breeding Flashcards
1
Q
Why is genetics important in cattle breeding?
A
- Prevention
- Economics
- Cumulative long lasting effects
2
Q
What are quantitative traits we measure and breed for?
A
- Milk yield
- Muscle growth rate
- most traits of economic interest
3
Q
What affects quantitative traits?
A
- Genes / genetics
- Environment
4
Q
What does high heritability mean?
A
- Can more easily improve trait through genetic selection
- Genes play more of a role than environmental factors
5
Q
What is pleiotropy?
A
- Genes affecting more than one trait
6
Q
What are other traits of interest?
A
- Feed efficiency/ dry matter intakes
- Greenhouse gas emissions!
- Immune response
- bovine tuberculosis (bTB) resistance
- Lameness
7
Q
What is bovine leucocyte adhesion deficiency?
A
- Single point mutation = fewer neutrophils get into tissue to fight infection
- CS = Ulcers on oral mucosa, gingivitis/periodontitis, chronic pneumonia + diarrhoea
- Death <1y/o
8
Q
What are genetic diseases?
A
- BLAD - bovine leucocyte adhesion deficiency
- CVM - complex vertebral malformation
- Bulldog calves / telemark lethal
- Holstein Haplotype for cholesterol deficiency (NEW)
9
Q
What is a PLI?
A
- Profitable life index - what to improve for a productive herd
- production, efficiency, survival, fertility, calving ability…
10
Q
Regarding conformation traits what is looked at with the legs/stance?
A
- Foot angle
- Rear legs rear view
- Rear legs side view
11
Q
Regarding conformation traits what is looked at with the udder?
A
- Udder depth
- Teat placement
- Rear udder width + depth
- Udder support
- Fore udder attachment
- Teat length
12
Q
Regarding conformation traits what is looked at with the rump + body?
A
- Rump angle
- Rump width
- Dairy form / angularity
- Strength
13
Q
What is the down side of having strong udder support?
A
- Udder cleft dermatitis can form
14
Q
What’s the downside of having weak fore udder attachment?
A
- Harder to milk
- Predisposed for udder cleft dermatitis
15
Q
A
