Equine Breeding Management Flashcards

1
Q

where is the breeding capital of thoroughbreds

A

Kentucky

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

stud fees range from_____ to ______________; foal values range from _______ to _______________

A

$100; $500,000; a few hundred; several million

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

T/F the equine industry varies greatly across breeds in breeding methods and costs/values

A

T

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

what is a stallions book

A

list of mares bred to stallion in a given year

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

cover vs mount

A

cover is natural breeding; mount is using a dummy

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

what are 4 methods of mare breeding

A

1) natural cover
2) on-farm AI
3) shipped fresh chilled AI
4) frozen AI

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

natural cover is the only method approved in what breed to obtain a registered foal

A

thoroughbreds

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

what are 4 advantages of natural cover

A

1) minimal equipment costs
2) it is obvious when the mare is in heat
3) no knowledge of semen handling needed
4) no semen shipments lost

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

what are 4 disadvantages of natural cover

A

1) risk of injury - need trained personnel
2) one mare bred per ejaculation
3) costly to bring mare to stallion
4) some mares will not accept stallion

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

what is one way to tell that the stallion ejaculated during natural cover

A

they may fall asleep afterwards

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

what is a unique concern with natural cover

A

need to be diligent with swabs and testing ahead of time to prevent spread of veneral diseases

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

what are some advantages of using AI

A

1) safety
2) more efficient as many mares can be bred with a single ejaculation
3) mare can stay at home
4) semen lasts 48+ hours when an extender is added
5) with frozen semen the stallion’s performance career is not interrupted

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

what are 2 disadvantages associated with AI

A

1) expenses of lab, shipping, mare management
2) requires a lot of knowledge in semen handling

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

frozen semen is stored at what temperature

A

-196 degrees C

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

one breeding dose of frozen semen is packed into how many straws and what size

A

1-8 1/2 mL straws

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

what are 2 disadvantages of using frozen semen

A

lower fertility rate; higher costs

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

what are 4 reasons for estrous cycle manipulation in mares

A

1) high costs associated with some foals
2) high costs associated with transporting the mare/semen
3) pressure for early foaling
4) for the purpose of embryo transfer, IVF, ICSI

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

what percentage of mares will cycle year round

A

10%

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

describe the uterus of a mare in anestrus

A

flaccid, no edema

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

when does spring transition occur in mares

A

march - april

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

what is spring transition characterized by

A

irregular or prolonged estrus periods with NO ovulation

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

why is there no ovulation during spring transition

A

there are no LH receptors on the LH and low bioactive LH

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

horses cycle every ____ days

A

21

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

what are some signs of estrus in the mare

A

winking, receptive to mare, increased urination, posturing

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

what are physical signs that the mare is in diestrus

A

aggressively refusing the stallion (kicking, biting, pinning ears)

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

what is characteristic of fall transition in horses

A

anovulatory follicles present on the ovary

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

what gene turns off during fall transition

A

LH gene

28
Q

T/F the fall transition is characterized by less progesterone and luteal failure

A

T

29
Q

what is the standard amount of light needed to bring a horse out of anestrus

A

14.5-16h total

30
Q

T/F you should add light to the start of the day to bring a horse out of anestrus

A

F; add to end of day

31
Q

horses resume cycling ______ days after you start the light program

A

60-70

32
Q

you should continue a lighting program for horses until days are naturally how long

A

14h (mid-March)

33
Q

you should start a lighting program in what period for February breeding

A

Nov 15 - Dec 5

34
Q

what is the most economical way to manipulate daylength in mares to bring them out of anestrus and how does it work

A

1.5-2h of high intensity light between 2am-4am; works because the photosensitive period in horses is 8-10 hours after onset of darkness

35
Q

does high or low wavelength light most effectively inhibit melatonin secretion

A

low

36
Q

T/F you should slowly increase the duration of light

A

F; just start right away with 14.5-16 h

37
Q

do the effects of season or the effects of foaling predominate

A

effects of season; meaning you need to put pregnant, early foaling mares in your program to ensure they continue cycling after foaling

38
Q

T/F PGF2α can be used to pull mares out of anestrus

A

F; no CL

39
Q

T/F GnRH and hCG can be used to pull mares out of anestrus

A

F; no LH receptor on follicles

40
Q

what hormone CAN be used to pull mares out of anestrus

A

dopamine antagonists (increase prolactin to stimulate follicular activity)

41
Q

sulpiride and domperidone are what

A

dopamine antagonists

42
Q

T/F dopamine antagonists are most effective at pulling mares out of anestrus when combined with lighting programs and estrogen

A

T

43
Q

what hormones can be used to pull horses out of spring transition

A

1) progesterone
2) domperidone and estrogen
3) GnRH or hCG

44
Q

what is Regumate

A

synthetic progesterone

45
Q

how often should you give regumate to induce the first ovulation and bring mares out of spring transition

A

10-14 days

46
Q

what is a consideration for using regumate to bring a mare out of spring transition

A

she must be mid-transition or later

47
Q

Τ/F you should give PGF2α to mares receiving progesterone therapy on the last day just in case she ovulated during treatment

A

T

48
Q

what is the estradiol and domperidone combination therapy

A

give initial injection of estradiol on the first day of therapy; give domperidone orally daily for 7-14 days

49
Q

estradiol/domperidone therapy hastens ovulation in what percentage of mares

A

40%

50
Q

why does the GnRH method of bringing a mare out of anestrus work poorly usually

A

lack of functional LH receptors

51
Q

when is PGF2α used most often in mare breeding

A

to control when she comes into estrus for planned breeding

52
Q

if you give a mare PGF2α on a friday, when should you expect her to come into ovulation and when should you be ready to breed

A

come into ovulation in 2-5 days (Mon/Tues) and breed by end of week

53
Q

T/F CIDRs are available for use in horses in NA

A

F

54
Q

what form of progesterone is most commonly used to prolong the luteal phase in horses

A

oral regumate

55
Q

T/F long-acting injectible progesterone can be compounded

A

T

56
Q

what are 2 other reasons to use progesterone in mares

A

1) keep her out of heat
2) help her maintain pregnancy

57
Q

when can hCG be used in mares

A

strong uterine edema and large follicles

58
Q

most horses ovulate how many hours after being given hCG

A

36h

59
Q

what is a problem with giving hCG

A

produces antibodies and therefore get reduced efficacy when used more than twice in a year

60
Q

if a mare is no longer responding to hCG, what should we switch to instead

A

GnRH

61
Q

what is deslorelin

A

GnRH analogue

62
Q

T/F GnRH is more expensive but more effective than hCG in inducing ovulation in mares in estrus

A

T

63
Q

follicles grow how much per day

A

3-6mm

64
Q

as ovulation approaches, follicles become

A

softer, more irregular, larger

65
Q

size of follicle on ovulation depends on (2) history

A

breed and mare

66
Q

describe the P and E combination program

A

daily progesterone and estradiol injections for 10 days; PGF2α on last day; in estrus 7-9 days later and ovulate day 20-21 of program