Lecture 11: Breeding Management and Infertility in Swine (Risco)

Question 1

accessory sex glands in boar

Answer 1

prostate
vesicular
bulboruethral

Question 2

biggest health problems in boars

Answer 2

lameness (laminitis)

Question 3

type of penis in boar

Answer 3

fibroelastic

Question 4

orientation of testes in boar

Answer 4

caudal (upside down)

Question 5

Describe sow’s repro tract

Answer 5

• bicornuate uterus
• paired ovaries
• red corpora lutea
• long, twisted cervix
• more resistant to uterine infections than other species

Question 6

when do boars hit puberty?

Answer 6

~9 mo.

Question 7

testosterone influence on puberty

Answer 7

–> penile growth (sigmoid flexure) + mounting behavior

Question 8

penile frenulum

Answer 8

breaks down during first breeding/puberty

Question 9

day light effect on puberty

Answer 9

inc. day light (15h/d) stimulatory in both boar and sow

Question 10

“gloved hand method”

Answer 10

method of boar semen collection in which boar trained to mount dummy and semen collected by hand

Question 11

most common method of breeding in swine

Answer 11

natural service

Question 12

volume of boar ejaculate

Answer 12

150-300ml/ejaculate (LARGE) w/ 30-60 million sperm/ejaculate

Question 13

ideal boar semen (motility/morph)

Answer 13

> 65% motile

>80% morphologically normal

Question 14

boar pheromones

Answer 14

5alpha-androstenone

• bound to proteins in boar saliva
• helps stimulate estrus in sows (via HPA axis), puberty in gilts, and mounting behavior in young boars
• sprays not recommended

Question 15

when do gilts hit puberty?

Answer 15

6-7mo.

Question 16

“Boar Effect”

Answer 16

helps stimulate puberty via pheromones

-continuous fence line exposure or full physical contact 10 mins/day

Question 17

puberty in gilts is defined as

Answer 17

the beginning of cyclicity (follicular growth, ovulation, estrus, CL, CH, etc.)

Question 18

estrous cycle in sow/gilt

Answer 18

• non-seasonal, polyestrus
• slight decrease in fertility during late summer
• 21 d
• SINGLE long follicular wave*

Question 19

how many follicular waves in lactating cows?

Answer 19

2

Question 20

how many follic. waves in mares, heifers?

Answer 20

3

Question 21

what causes standing heat (2-3d) in sows?

Answer 21

follicular estradiol

Question 22

how long after onset of estrus does ovulation occur?

Answer 22

35-44hrs (2/3 into estrus)

Question 23

flush feeding

Answer 23

increase feed intake few days-2 weeks before estrus to increase # of oocytes. Helps with HPA axis

Question 24

polytaucus (sp?) animals

Answer 24

bitch, sow, queen, SR. (often bare more than 1 fetus)

Question 25

at what point in estrous cycle is CL functional?

Answer 25

by day 5-6

Question 26

when will sow respond to exogenous PGF2a?

Answer 26

after day 12-13

Question 27

T/F: non-pregnant uterus naturally releases PGF2a which lyses CL and returns sow to estrus

Answer 27

T

Question 28

standing heat

Answer 28

when sow allows mounting by the boar

Question 29

back pressure test

Answer 29

firm pressure on back or sacrum causes sow to show standing heat

Question 30

how long does estrus last in sow? cow?

Answer 30

2-3 days; cow: 14-16hrs

Question 31

2ary signs of estrus

Answer 31

``` restlessness during feeding not settling down after feeding frequent small-volume urination ear cocking red, swollen vulva with mucoid discharge ```

Question 32

swine breeding methods

Answer 32

pen mating (most common, natural service) hand breeding AI

Question 33

major reproductive diseases in swine

Answer 33

``` PRRSV** Brucellosis Parvo Virus** Lepto Postpartum Dysgalactia Syndrome Pseudorabies Swine Influenza ```

Question 34

PRRSV =

Answer 34

Porcine Respiratory and Reproductive Syndrome Virus

Question 35

PRRSV chars.

Answer 35

- -A Lelystad virus - respiratory signs wean-finish - repro losses in all stages of production (abortions, stillbirths, etc.) - Epi: aerosol, pig to pig, semen trans. - acute (epizootic) or chronic (endemic)

Question 36

Parvovirus immunity

Answer 36

- delayed loss of maternal AB - 6-8 mo. of age decline and susceptible to infection - vaccination, acclimatization possible

Question 37

Parvo chars.

Answer 37

- causes SMEDI: stillbirth, mummies, embryonic death, infertility - common, ubiquitous, endemic - viremia, fetal vasculitis, death - prolonged gestations, small litters, etc. - primarily gilt disease

Question 38

what percent of oocytes are fertilized?

Answer 38

~100%

Question 39

what percent of oocytes die within first 30 days? Until term?

Answer 39

20-30% by first 30 days, another 10% by term (~40% loss overall)

Question 40

uterine capacity

Answer 40

uterus limits # of embryos that survive

Question 41

embryos enter uterus how many days after conception?

Answer 41

2-4 days

Question 42

how long do embryos migrate?

Answer 42

2 wks

Question 43

implantation occurs when?**

Answer 43

14-18d

Question 44

maternal recognition of pregnancy is determined by:

Answer 44

interferon tao/estradiol

Question 45

which species are CL dependent?***

Answer 45

sow cow small ruminants (mainly goats) (bitch, queen to lesser extent)

Question 46

when do embryos secrete estradiol? what is the significance of this?***

Answer 46

day 10-11; maternal recognition of pregnancy (2nd peak occurs after day 14)

Question 47

hormone progression of non-pregnant cycling sow

Answer 47

1. oxytocin released from posterior pituitary AND CL | 2. oxytocin releases prostaglandin, which then becomes ENDOCRINE in nature --> regression of CL

Question 48

hormone progression of pregnant non-cycling sow

Answer 48

1. blastocyst releases estrogen | 2. prostaglandin is EXOCRINE in nature and is released but is NOT absorbed and doesn't get back to CL

Question 49

oxytocin receptors in endometrium are upregulated by:

Answer 49

estrogen (from follicles)

Question 50

how many embryos needed to maintain pregnancy up to 30 days?

Answer 50

2 per horn

Question 51

how many fetuses total required to maintain pregnancy after 30 days?**

Answer 51

2 total

Question 52

sow gestation length

Answer 52

114 days (3 mo, 3 wks, 3 d)

Question 53

average litter size

Answer 53

11

Question 54

swine placenta type

Answer 54

diffuse epitheliochorial (see slide 31)

Question 55

what is parturition called in swine?

Answer 55

farrowing

Question 56

methods of pregnancy dx in swine

Answer 56

- failure to return to estrus at 17-25 days after breeding - rectal palpation (>90% accurate after 30 days) - ultrasound

Question 57

3 types of US used in swine for preg. dx

Answer 57

1) Doppler - Rectal/Transabdominal 2) Amplitude-Depth (A-mode) 3) Real-Time (B-mode) <-- most common

Question 58

When can Doppler-Rectal/Transabdominal US detect pregnancy?*** What does it also detect?

Answer 58

after 30 days of gestation-term. Detects inc. blood flow to uterine a., fetal heart, or umbilical aa. (150-250bpm)

Question 59

When can Amplitude-Depth (A-mode) US detect pregnancy? What does it also detect?

Answer 59

28-80 days after breeding. Detects fluid in uterus

Question 60

When can Real-Time (B-mode) US detect pregnancy?

Answer 60

16-20 days rectally, >21 days transabdominally

Question 61

avg. farrowing takes how long?

Answer 61

2-5 hrs

Question 62

placenta delivered how long after delivery?

Answer 62

4 hrs

Question 63

induction of parturition advantage

Answer 63

- ensures attendance of farrowing --> inc. survival rate of pigs - chance to cross-foster pigs to sows w/ small litters

Question 64

how to induce parturition

Answer 64

prostaglandin (PGF2a): - tx 1-2 days before due date - most will farrow w/n 36 hrs - can give oxytocin if no response

Question 65

lactational anestrus

Answer 65

inability of sows to cycle while nursing (normal) - wean pigs and sows will return to estrus by 28 days post farrowing - boar exposure can help synchronize sows

Question 66

losing weight --> neg. energy balance --> ketotic --> betahydroxybutarate increases, glucose decreases, etc. --> HPA axis disrupted

Answer 66

(prevented by proper diet)

Question 67

sows weaned during which season may take longer to return to estrus?

Answer 67

summer (due to dec. feed intake)

Question 68

boars can get what if diet too rich in calcium/minerals?

Answer 68

spondylosis deformans

Question 69

larger testes size in boars correlates to what in daughters?

Answer 69

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