Flashcards in Population genetics: farm animals Deck (21):
Who produces the rules for Organic production?
Predicted Transmitting Ability. This is the genetic merit of the animal as a breeding value. It is a specific calculation from coorporations such as DairyCo suing national genetic evaluations.
What are selection indices?
Combinations of desirable traits
What do selection indices allow us to do? 2
- independently rank bulls
- combine PTAs using relative values
What are indeces used for?
Traditionally - increase production and profit
Also - incorporate welfare, health and functional traits
Recently - looked at the transition from wider production indexes to those incorporating a variety of traits
What might be a index where the goal is fertility?
What does the £PLI contain? 6
Milk PTA, Fat PTA, Protein PTA
Is SCC a good predictor of mastitis?
Yes - genetic correlation between them is around 0.65/ Heritability f SCC approx 0.11 (mastitis <0.05)
Do genetic links exist between production, health and fertility traits?
Yes - e.g. milk, fat and protein with mastitis is approx 0.3
What does a fertility index include?
You combine a fertility trait PTA or a combination of traits with its relative economic value.
Define non-return rate
the % herd that are returning to oestrous a certain number of days past the last calving (usually 56 days are used)
What can genetic improvement deliver? 4
greater efficiency of production
Why does the £PLI need to be updated? 2
changes in costs/returns
investigate a range of scenarios
How has the £PLI been enhanced in recent years? 2
addition of fertility
revision of economic values
How will the future dairy cow be 'improved'?
milk of the right composition
milk made in the 'right' way
body energy loss
Why should health and welfare traits be considered? 4
large industry pull
deals with several crucial traits together
satisfies government and society objectives together
expected annual returns to the industry very high
What are functional traits?
rump width and angle, angularity, body depth, stature, temperament, chest width, foot angle, milk (yield/fat/protein), fore udder, rear udder height, udder support, udder height, teat position, overall udder score.
What is the estimated annual cost of lameness in the UK?
over £90 million
What are important considerations of bull selection?
selection made on whole herd or individual cow basis