Swine Repro

Question 1

What is a gilt?

Answer 1

a female pig that has not had any offspring

Question 2

What is a sow?

Answer 2

a female pig that has had offspring

Question 3

When does puberty typically occur in a female pig?

Answer 3

150-220 days: producers want 180 days

Question 4

What are factors that affect when puberty begins?

Answer 4

boar contact and the housing environment

Question 5

What type of breeders are female pigs?

Answer 5

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

Question 6

What are the phases of the pig estrous cycle?

Answer 6

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

Question 7

When does the pre-follicular phase occur in pigs?

Answer 7

4-6 days prior to the follicular phase

Question 8

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

Answer 8

follicular development is largely suppressed

Question 9

When does the follicular phase occur?

Answer 9

4-6 days following the luteal phase or lactation

Question 10

How many follicles typically ovulate during the follicular phase?

Answer 10

15-30

Question 11

What is the size of the dominant follicles?

Answer 11

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

Question 12

When does the luteal phase occur?

Answer 12

immediately after ovulation

Question 13

What hormone levels rise during the luteal phase?

Answer 13

progesterone

Question 14

What happens in lactational anestrous?

Answer 14

LH pulsatility is suppressed from suckling inhibition on GnRH

Question 15

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

Answer 15

the pre-follicular phase

Question 16

What is the BPT and how does it work?

Answer 16

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

Question 17

How long are pigs typically in standing estrus?

Answer 17

40-60 hours (24-90 hours)

Question 18

When does ovulation typically occur in pigs?

Answer 18

two thirds of the way into standing estrus

Question 19

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

Answer 19

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

Question 20

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

Answer 20

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

Question 21

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

Answer 21

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

Question 22

What happens to follicles during anestrous?

Answer 22

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

Question 23

When does estrus occur post-weaning?

Answer 23

4-7 days

Question 24

What signaling molecule is used to signal pregnancy in pigs?

Answer 24

estrogen

Question 25

What is estrogen produced by during pregnancy?

Answer 25

conceptus

Question 26

What does estrogen do during pregnancy?

Answer 26

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

Question 27

What does PGE2 do during pregnancy?

Answer 27

it protects PGF 2 alpha luteolytic effects on the CL

Question 28

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

Answer 28

4

Question 29

When must estrogen be present during pregnancy?

Answer 29

at days 11-12 and 15-18

Question 30

Why must estrogen be present on days 11-12?

Answer 30

to extend diestrus

Question 31

Why must estrogen be present on days 15-18?

Answer 31

for reinforcement to carry to term

Question 32

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

Answer 32

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

Question 33

What supploes progesterone during pregnancy?

Answer 33

the CL

Question 34

How long is gestation in the pig?

Answer 34

114 days

Question 35

When can pregnancy be diagnosed by abdominal ultrasound?

Answer 35

21-25 days

Question 36

What type of placenta does the pig have?

Answer 36

epithelialchorial diffuse

Question 37

When does progesterone decline during pregnancy?

Answer 37

10-14 days prior to parturition

Question 38

What is relaxins role during pregnancy?

Answer 38

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

Question 39

When does puberty occur in the male?

Answer 39

5-9 months

Question 40

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

Answer 40

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

Question 41

How long is the spermatogenic cycle in the male?

Answer 41

47 days

Question 42

How long does spermatogenesis occur?

Answer 42

35 days

Question 43

How long does epididymal transit take?

Answer 43

12 days

Question 44

What is the swine penis shaped like and why?

Answer 44

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

Question 45

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

Answer 45

clear with some gel from the vesicular gland

Question 46

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

Answer 46

sperm rich with gel

Question 47

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

Answer 47

mostly gel from the bulbourethral gland

Question 48

How often is sperm collected from the boar?

Answer 48

every 5 days

Question 49

Describe natrual copulation in the boar.

Answer 49

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

Question 50

How many days are between weaning and servicing?

Answer 50

4-7 days

Question 51

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

Answer 51

40 days

Question 52

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

Answer 52

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