Population genetics: farm animals

Question 1

Who produces the rules for Organic production?

Answer 1

Soil Association

Question 2

Define PTA

Answer 2

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.

Question 3

What are selection indices?

Answer 3

Combinations of desirable traits

Question 4

What do selection indices allow us to do? 2

Answer 4

• independently rank bulls

- combine PTAs using relative values

Question 5

Define PIN

Answer 5

Production Index

Question 6

What are indeces used for?

Answer 6

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

Question 7

What might be a index where the goal is fertility?

Answer 7

Calving interval

Question 8

What does the £PLI contain? 6

Answer 8

Milk PTA, Fat PTA, Protein PTA
Lifespan PTA
SCC PTA
Locomotion PTA

Question 9

Is SCC a good predictor of mastitis?

Answer 9

Yes - genetic correlation between them is around 0.65/ Heritability f SCC approx 0.11 (mastitis <0.05)

Question 10

Do genetic links exist between production, health and fertility traits?

Answer 10

Yes - e.g. milk, fat and protein with mastitis is approx 0.3

Question 11

What does a fertility index include?

Answer 11

You combine a fertility trait PTA or a combination of traits with its relative economic value.

Question 12

Define non-return rate

Answer 12

the % herd that are returning to oestrous a certain number of days past the last calving (usually 56 days are used)

Question 13

What can genetic improvement deliver? 4

Answer 13

higher output
lower costs
greater efficiency of production
healthier cows

Question 14

Why does the £PLI need to be updated? 2

Answer 14

changes in costs/returns

investigate a range of scenarios

Question 15

How has the £PLI been enhanced in recent years? 2

Answer 15

addition of fertility

revision of economic values

Question 16

How will the future dairy cow be ‘improved’?

Answer 16

milk of the right composition
milk made in the ‘right’ way
body energy loss
environmental sensitivity

Question 17

Why should health and welfare traits be considered? 4

Answer 17

large industry pull
deals with several crucial traits together
satisfies government and society objectives together
expected annual returns to the industry very high

Question 18

What are functional traits?

Answer 18

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.

Question 19

What is the estimated annual cost of lameness in the UK?

Answer 19

over £90 million

Question 20

What are important considerations of bull selection?

Answer 20

individual traits
genetic evaluation
selection made on whole herd or individual cow basis

Question 21

List some online programs that help you select a bull

Answer 21

AltaMateUK (Alta)
Herdmate (Cognent)
Herdmate+ (Cogent)
GMS (Genus)
Promate (Semex)
WMS (World Wide Sires)
Webmate (HolsteinUK)`