Genetics > Equine Selection > Flashcards

Equine Selection Flashcards

(50 cards)

Study These Flashcards
1
Q

Why are horses the least studied of livestock?

A
  • recreational use
  • long GI (generation interval)
  • long gestation
  • age to puberty
  • offspring/year
  • lack of accurate records
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does a higher GI result in?

A

reduced rate of genetic change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the gestation length of horses?

A

336 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why are there problems determining heritability in horses?

A
  • variation
  • tremendous environmental variation
  • data bias
  • limited information available is probably higher than reality
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What problems arise determining heritability in racing horses?

A
  • surface
  • condition
  • age
  • level of training
  • nutrition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why is horse age a problem?

A

horses have a universal birth date

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why is level of training a problem?

A

are you measuring the genes of the horse of the trainer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What problems result from data bias?

A
  • not all contemporaries are allowed the same opportunity (performance)
  • selection of animals is based on likelihood to excel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What horse traits are of economic importance?

A
  • fertility
  • performance
  • cow sense
  • jumping ability
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the heritability of fertility?

A

0.05

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How do horses perform fertility compared to other species?

A

lower performance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why do horses have lower fertility performance compared to livestock species?

A
  • duration of estrus/time of ovulation
  • artificial birth date
  • hand mating/pasture mating/AI
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does heritability reported measure to actual heritability of fertility?

A

it is probably higher than reported due to man’s influence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Have horses had improvement in fertility from selection?

A

very little

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How have horses had more successful fertility?

A

changes in environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What changes are made to environment to improve fertility?

A
  • nutrition
  • health care
  • breeding seasons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is horse performance important for?

A
  • racing
  • cattle work
  • barrel racing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the basis for racing?

A

anatomy and physiology

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is important for racing?

A
  • stride length
  • frequency of strife
  • muscle fiber type
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the two types of muscle fiber types?

A
  • slow twitch or type 1

- fast twitch or type 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

For performance, obvious some degree of heritability based on _____.

Study These Flashcards
A

skeletal structure

22
Q

Has there been any improvements on the speed index?

Study These Flashcards
A

not in the last 60 years

23
Q

What are sales of horses based on?

24
Q

What methods are there to measure heritability?

Study These Flashcards
A
  • speed index
  • lifetime earnings
  • average earnings
25
What is the speed index for horses?
AQHA
26
What may limit heritability accuracy in performance?
limited contemporary measuring
27
what is heritability of racing ability in TB?
0.35
28
Is trotters dominant or recessive?
dominant
29
Is pacers dominant or recessive?
recessive
30
Can you teach trotters to pace?
it's difficult
31
What is the heritability of trotters/pacers?
0.10-0.25
32
What are the functions of cattle work?
- ranch work - roping - cutting
33
What is ranch work?
work livestock over rough terrain
34
What is roping include?
- close contact to animals | - high agility
35
What does cutting include?
- highly athletic | - respond to calf movement after separation from herd
36
What is cow sense?
horse appearing to have a great interest in cattle
37
Can cow sense be researched?
it's difficult to
38
What is barrel racing based on?
speed and agility
39
What is the history of horse selection?
- development of distinct breeds and types of horses in last few thousand years - manufactured "registered" breeds
40
Are color breeds purebred?
no
41
Do Palominos breed true?
no
42
What mating systems are used for horses?
- linebreeding - Positive assortative mating - inbreeding - crossbreeding
43
How common is linebreeding?
very common
44
What is linebreeding?
concentrating the genes from one individual
45
What is positive assortative mating?
breeding the best to the best
46
What is a major selection criteria for positive assortative mating?
sire performance
47
Is Inbreeding commonly used?
used little
48
Is crossbreeding commonly used?
somewhat
49
When is crossbreeding used in horse industry?
- breed development - warmbloods - trotters
50
What detrimentals are selected against?
- CID - Bleeders - OCD or DOD - Wobblers Syndrome - HYPP - Lethal White Foal Syndrome - HC/HERDA - GBED
Genetics
flashcards
Decks in class (24)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions