Swine Repro Flashcards Preview

Histology Pt. 2 > Swine Repro > Flashcards

Flashcards in Swine Repro Deck (52)
Loading flashcards...
1
Q

What is a gilt?

A

a female pig that has not had any offspring

2
Q

What is a sow?

A

a female pig that has had offspring

3
Q

When does puberty typically occur in a female pig?

A

150-220 days: producers want 180 days

4
Q

What are factors that affect when puberty begins?

A

boar contact and the housing environment

5
Q

What type of breeders are female pigs?

A

non-seasonal, polyestrous, polytocous: 21 day estrous cycle (18-24 days)

6
Q

What are the phases of the pig estrous cycle?

A

pre-follicular phase, follicular phase, luteal phase, lactational anestrous

7
Q

When does the pre-follicular phase occur in pigs?

A

4-6 days prior to the follicular phase

8
Q

What occurs to the follicle in the pre-follicular phase?

A

follicular development is largely suppressed

9
Q

When does the follicular phase occur?

A

4-6 days following the luteal phase or lactation

10
Q

How many follicles typically ovulate during the follicular phase?

A

15-30

11
Q

What is the size of the dominant follicles?

A

2-4 mm are predestined to be dominant and they turn into 7-8 mm follicles

12
Q

When does the luteal phase occur?

A

immediately after ovulation

13
Q

What hormone levels rise during the luteal phase?

A

progesterone

14
Q

What happens in lactational anestrous?

A

LH pulsatility is suppressed from suckling inhibition on GnRH

15
Q

What phase is the number of follicles that will ovulate dependent on?

A

the pre-follicular phase

16
Q

What is the BPT and how does it work?

A

it is the back pressure test, if a pig is in standing estrus and you put pressure on their back they will not lay down, they will stay standing

17
Q

How long are pigs typically in standing estrus?

A

40-60 hours (24-90 hours)

18
Q

When does ovulation typically occur in pigs?

A

two thirds of the way into standing estrus

19
Q

When do we typically breed gilts after standing estrus has been detected?

A

twice/day detection: 12 hours for the first breeding and then 12 hours after that for the second
once/day detection: 4 hours for the first breeding and then 12 hours after that for the second breeding

20
Q

When do we typically breed sows when twice/day estrus detection is done?

A

24 hours for the first breeding and then 24 hours after that for the second breeding

21
Q

When do we typically breed sows when once/day heat detection is done?

A

12 hours for the first breeding and then 24 hours after that for the second breeding

22
Q

What happens to follicles during anestrous?

A

the follicular pool increases during lactation and at the end of it they synchronize and follicle diameter increases

23
Q

When does estrus occur post-weaning?

A

4-7 days

24
Q

What signaling molecule is used to signal pregnancy in pigs?

A

estrogen

25
Q

What is estrogen produced by during pregnancy?

A

conceptus

26
Q

What does estrogen do during pregnancy?

A

alters direction of PF2 alpha, increases PGE2 secretion by the uterus and maintains LH-R on the CL

27
Q

What does PGE2 do during pregnancy?

A

it protects PGF 2 alpha luteolytic effects on the CL

28
Q

How many conceptuses are needed ‘turn on’ the maternal recognition molecule?

A

4

29
Q

When must estrogen be present during pregnancy?

A

at days 11-12 and 15-18

30
Q

Why must estrogen be present on days 11-12?

A

to extend diestrus

31
Q

Why must estrogen be present on days 15-18?

A

for reinforcement to carry to term

32
Q

If we want to eliminate pregnancy, when must we do it and how?

A

at day 12 of the cycle and by introducing PGF 2 alpha

33
Q

What supploes progesterone during pregnancy?

A

the CL

34
Q

How long is gestation in the pig?

A

114 days

35
Q

When can pregnancy be diagnosed by abdominal ultrasound?

A

21-25 days

36
Q

What type of placenta does the pig have?

A

epithelialchorial diffuse

37
Q

When does progesterone decline during pregnancy?

A

10-14 days prior to parturition

38
Q

What is relaxins role during pregnancy?

A

relaxin rises and inhibits oxytocin until 12-15 hours prior to parturition

39
Q

When does puberty occur in the male?

A

5-9 months

40
Q

What creates the submaxillary salivary glands and when do they typically grow?

A

5 alpha androstenone and 3 alpha androstenol (testosterone derivatives) at 10-11 months

41
Q

How long is the spermatogenic cycle in the male?

A

47 days

42
Q

How long does spermatogenesis occur?

A

35 days

43
Q

How long does epididymal transit take?

A

12 days

44
Q

What is the swine penis shaped like and why?

A

a spiral with a big sigmoid flexure to fit into the cervix of the female

45
Q

What is the make up of the first fraction of ejaculate and where does it come from?

A

clear with some gel from the vesicular gland

46
Q

What is the make up of the second fraction of ejaculate?

A

sperm rich with gel

47
Q

What is the make up of the third fraction of ejaculate and where does it come from?

A

mostly gel from the bulbourethral gland

48
Q

How often is sperm collected from the boar?

A

every 5 days

49
Q

Describe natrual copulation in the boar.

A

thrusting until the penis is engaged in the cervix, ejaculation happens after thrusting

50
Q

How many days are between weaning and servicing?

A

4-7 days

51
Q

How long does a gilt need to be in contact with a boar to induce cyclicity?

A

40 days

52
Q

What exogenous drugs can be used to induce cyclicity if a gilt is not cycling by by the 180 day point?

A

PG600 - acts like FSH, and HCG - acts like LH