Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Equine Evaluations > Selecting Horses for Breeding > Flashcards

Selecting Horses for Breeding Flashcards

1
Q

Live cover/natural service

A

-all breeds/disciplines
-mare and stallion in same location

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

Assisted reproduction

A

-most breeds/disciplines (not the TB)
-artificial insemination
-embryo transfer
-other technologies

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

What to look for in mating decisions:

A

-reproductive health/capacity
-genetic value
-economics

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

Genetic value

A

ability to pass on desirable traits

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

Reproductive health/capacity

A

ability to produce an acceptable # of progeny

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Stallions reproductive health:

A

-ability and willingness to mount and breed
-libido
-physical soundness

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

Busy “live cover” systems for stallions:

A

3x/day

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

Busy AI systems for stallions:

A

3x/week

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Stallion reproductive capacity:

A

-adequate number of fertile sperm
-live covers: each ejaculate must contain sufficient sperm for one mare
-AI: collections are usually subdivided (multiple mares); sperm must remain fertile after cooling or freezing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Objective measures of stallion services/pregnancy:

A

-Live cover: how many times does a stallion need to breed to get a mare pregnant?
-AI: how many times must the mare be inseminated to get pregnant?

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

Under high management, how many breedings or inseminations per pregnancy?

A

~1.5

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

1 ejaculate = how many doses?

A

1 (one mare bred per ejaculate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Under very busy live cover how many mares per day?

A

3-4 mares/day

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

Under very busy live cover how many mares per week?

A

21-28 mares/week

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

How many doses for AI does a normal stallion produce?

A

5-15 insemination doses

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

What is the typical AI schedule?

A

4 days/week

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

About how many mares would ejaculate from one stallion be “breeding” per week?

A

20-60 mares/week

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the pregnancy rate of stallions under high management?

A

80-90%

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

Calculation of pregnancy rate:

A

(# mare pregnant/# mares bred) x 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Calculation of live foal rate:

A

(# live foals/# mares bred) x 100

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

Live foal rate

A

65-75%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Evaluations of reproductive capacity are…

A

dynamic (can change over time)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

When do stallions become successful?

A

when their progeny do well
-they must have enough progeny to be visible to mare owners

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Live foal guarantee

A

stallion owner gets paid if there is a live foal. If a mare is bred several times and does not produce a foal, the stallion manager has invested time and effort for no payment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Selection criteria for popular/busy stallions:

A

-may turn down mares with poor repro records
-may turn down mares foaling late in the year
-may favor young mares

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Selection criteria for unpopular stallions:

A

-may want to accept as many mares as possible
-older mares
-less fertile mares

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Selection criteria for less fertile stallions:

A

-may exert same criteria as for busy stallions
-may limit number of mares bred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Two ways to increase stud farm income:

A

-more live foals
-higher stud fees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Why might the number of mares bred to a stallion decrease?

A

-the stallion manager decides the stallion has reduced breeding capacity and can not or will not breed a larger number of mares successfully
-the mare owner decides the stallions progeny aren’t doing well, the stud fee is more than current market value, or there is elevated risk that their mare will not get in foal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Why might the number of mares bred to a stallion increase?

A

-the stallion manager decides the stallion is capable of breeding more mares than originally expected
-the mare owners decide the stallions progeny are doing well, or the stud fee has been reduced to a better value

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Mare reproductive health/capacity is based on:

A

their ability to conceive
-functional ovaries, oviducts, uterus, etc.
-applies to live cover, AI, and ET systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Mare reproductive physical health/capacity depends on:

A

physically sound/healthy enough to carry a foal to full term and deliver normally
-applies to live cover and AI
-may not apply if embryo transfer is used

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How else do mares need to qualify for breeding?

A

they must be physically and mentally sound/healthy enough to raise a foal to weaning
-may not apply if ET is used or a nurse mare

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Live foal rate can be calculated as:

A

-# live foals/# years bred
-# live foals/years in service
-# live foals/years pregnant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Measures of reproductive ability in mares:

A

-live foal rate
-services or cycles bred/pregnancy
-time between foaling dates (or between foaling date and last breeding date)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Things to think about when considering mares:

A

-how old is she?
-how many foals has she had?
-at what age could she have her first foal?
-how many years could she have been bred
-how many years was she bred
-possible reasons a year was skipped
-when will she foal next year
-when can you expect to breed her next

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Mare gestation length

A

320-362 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Natural breeding season start:

A

about the beginning of April

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Commercial breeding season start:

A

about the beginning of February

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Reproductive capacity

A

able to produce acceptable # of progeny

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Genetic value

A

able to pass on traits of interest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Traits of interest in breeding horses:

A

-physical
-athletic
-reproductive
-behavioral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Genotype

A

the genetic component of a trait

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Phenotype

A

the composite characteristics of a trait that result from both genetic and environmental components

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

P = ? + ?

A

genotype + environmental factors

46
Q

Heretability

A

the portion of variation in a trait under genetic control

47
Q

Heritability of 0.0

A

no genetic influence

48
Q

Heritability of 1.0

A

trait is completely under genetic control

49
Q

For highly heritable traits is it easy or hard to assess genetic value?

A

relatively easy…what you see is what you get

50
Q

The lower the heritability value is it easier or harder to assess genetic value?

A

more difficult

51
Q

Heritability of size

A

0.5-0.9 - highly heritable

52
Q

Heritability of leg conformation

A

0.1-0.7 - wide range

53
Q

Heritability of jumping

A

0.1-0.3 - low genetic influence

54
Q

Heritability of cutting

A

<0.1-0.2 - low genetic influence

55
Q

Heritability of fertility

A

<0.1-0.2 - low genetic influence

56
Q

Heritability of TB racing ability

A

0.2-0.5 - low to mid range

57
Q

Heritability of QH racing ability

A

0.2-0.4 - low range

58
Q

Heritability of StB racing ability

A

0.2-0.4 low range

59
Q

What heritability do most performance traits have?

A

below 5.0

60
Q

Predicting genetic value accurately you need:

A

must have objective records of the horse of interest

61
Q

What are types of objective records?

A

-wither height/body weight
-color
-competition earnings
-race times

62
Q

What are types of subjective records?

A

-jumping ability
-temperament
-breed type

63
Q

Subjective

A

based on opinion

64
Q

What might make subjective records more objective?

A

scoring systems
-if competitions use specific scoring standards

65
Q

No record is not the same as…

A

a poor record

66
Q

Bias

A

a situation that could influence records in a systematic way

67
Q

Who’s records are available?

A

-individual’s own
-individual’s progeny
-individual’s parents
-individual’s grandparents’

68
Q

When is the heritability and assessment of genetic value in stallions the highest?

A

when they have 200 or more progeny

69
Q

How can a mares genetic value be assessed?

A

-higher number of progeny the better (but most have <10 so it is hard to assess)
-mare’s performance record
-records of relatives

70
Q

What relationship to a stallion or mare gives their best prediction of genetic value?

A

progeny

71
Q

What must the records be for genetic value accuracy?

A

they must have records of a comparable population

72
Q

Average TB

A

winning a race

73
Q

Above average TB

A

placing 2nd or 3rd in a black type stake

74
Q

Far above average TB

A

winning a black type stake

75
Q

Elite TB

A

winning a G1 race

76
Q

Average progeny starters %

A

65-70%

77
Q

Average progeny winners %

A

45-50%

78
Q

What % of progeny is black type stakes winners?

A

3-4%

79
Q

Average Earnings Index (AEI)

A

a ratio comparing the average earnings of a stallions progeny with the average earnings of all other horses running in a given country during a specific year or time period

80
Q

An average AEI

A

1

81
Q

An above average AEI

A

AEI>1

82
Q

A below average AEI

A

AEI < 1

83
Q

What is above average for TB progeny?

A

-more than 50% winners
-more than 3.5% black type winners
-AEI > 1

84
Q

Primary source of bias

A

mare quality is not the same across all stallions

85
Q

Secondary source of bias

A

environment (management is not the same for the progeny of all stallions)

86
Q

Comparable Index (CI)

A

-provides insight into quality of mares bred to a specific stallion

87
Q

How is the CI calculated?

A

calculated from the average earnings of starters from mares that he bred, when they were bred to other stallions, divided by the average earnings of all contemporary starters

88
Q

CI = 1

A

means when bred to other stallions the mares produced progeny that had earnings equal to the average horse in the population

89
Q

CI = 2

A

means when bred to other stallions the mares produced progeny that had earnings two times the average horse in the population

90
Q

The higher the CI,

A

the better the mare quality

91
Q

A lower CI, above 1, would means what?

A

the stallion “improved” the progeny of the mares he bred the most

92
Q

About what % of the progeny of the best stallions never win a black type race?

A

90%

93
Q

What is the AEI of the best stallions?

A

around 2 or higher

94
Q

What does the CI tell us about mare quality?

A

the CI helps us understand whether the stallion is breeding mares that are above, at, or below average

95
Q

Owner goals

A

-breed to sell
-breeding to keep for performance
-breed to compete and keep for breeding (fillies usually)

96
Q

Budget and cash flow considerations

A

-not all mares warrant the same investment in stud fees
-some breeders will breed to sell and breed to compete

97
Q

Physical attributes of mare and stallion that are considered:

A

-usually avoid duplicating defects
-sometimes select to correct a defect/weakness
-like to like or opposites attract?

98
Q

Mating schemes within breed:

A

-outcrossing
-inbreeding
-nicking

99
Q

Outcrossing

A

mating of two “unrelated” horses of the SAME breed
-unrelated through usually 4th or 5th generations

100
Q

Crossbreeding

A

mating of horses from different breeds
-introduce new traits
-not used in TB’s
-important to creating new breeds

101
Q

Inbreeding

A

increase the influence of desirable ancestors
-a horse is considered inbred if an ancestor appears on both sides (maternal and paternal) of the pedigree

102
Q

2 x 3 inbreeding

A

not common, but sometimes seen

103
Q

3 x 3 inbreeding

A

occasionally, usually with excellent individuals

104
Q

3 x 4 inbreeding

A

common

105
Q

4 x 4, 4 x 5 inbreeding

A

very commone

106
Q

A horse that is not “inbred” itself may still…

A

have inbreeding in their pedigree
-the sire could be inbred to one or more horses
-the dam could be inbred to other horses

107
Q

When is crossing of two inbred lines sometimes practiced?

A

to duplicate a successful cross of a certain sire and dam in the past

108
Q

Nick

A

a successful cross

109
Q

Nicking patterns

A

-some stallions do well with any type of mare, others have more success with mares from certain sire-lines
-some mares come from families with more success when bred to certain sire lines

110
Q

Nicking programs

A

input a mare for a particular stallion
-program usually grades the success of the cross of the stallions sire line over the mares sire line

111
Q

What do nicking programs disregard?

A

the maternal families of both stallion and mare

112
Q

What do nicking programs do for young stallions?

A

go back to their sire or grandsire’s records

Equine Evaluations (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions