Pig Reproduction

Question 1

What is the gestation period of a pig?

Answer 1

115 days (3 months 3 weeks 3 days)

Question 2

How old are piglets when they are weaned? What weight?

Answer 2

4 weeks - 7kg

Question 3

How many days between weaning and a sow being back in oestrus again?

Answer 3

~5 days

Question 4

What age do pigs reach puberty? What weight are they when they are first serviced?

Answer 4

6-8 months - 120kg

Question 5

Why would a farmer not service a pig in the first oestrus?

Answer 5

Bigger litter if wait for the second or third oestrus

Question 6

When buying gilts for a farm, what is advisable for her disease status?

Answer 6

Matching that of the farm

Question 7

Describe the process of fertilisation in sows

Answer 7

Happens in the oviduct - Eggs then secrete oestradiol - Acts on uterus to stop prostaglandin production - Prevents luteolysis

Question 8

What are the common ways to PD sows?

Answer 8

Non-return to oestrus (every 21 days) - Ultrasound (large uterus, done by stockman)

Question 9

How would you induce farrowing in a sow? What are the disadvantages?

Answer 9

Intravulval injection of prostaglandins/oxytocin - cost, must know gestation dates (only works a couple days before due)

Question 10

On average, which litters are the most productive for sows? After how many are they generally culled?

Answer 10

3-5 - after litter 6

Question 11

Why are boars very useful on a pig farm?

Answer 11

Help with oestrus detection - Increase the semen uptake in the sows (even if serviced) - Increase the duration of oestrus

Question 12

What is the advantages of weaning at 4 weeks instead of 3 weeks?

Answer 12

Lactation may be longer but there is a shorter weaning to oestrus interval and a longer oestrus

Question 13

What problems are there if sows are returning to oestrus at a) regular intervals b) irregular intervals?

Answer 13

a) Problem with conception (poor AI/semen uptake)

b) Sow problems (loss of litter)

Question 14

What are the non-infectious causes of abortion in sows?

Answer 14

Poor hygiene - Poor management - Stress (eg heat stress)

Question 15

What kind of pathogens are infectious causes of abortion? Give examples

Answer 15

Opportunists - Swine influenza - Porcine Reproductive and Respiratory syndrome - Leptospirosis - Erysipelas - Porcine Circovirus 2

Question 16

What are the clinical signs of PRRS?

Answer 16

Reproductive loss - Increased pre-weaning mortality - Respiratory effort in neonates (thumps)

Question 17

How is leptospirosis spread? What are the implications of this?

Answer 17

Spread venerally - Need to treat boars if discovered

Question 18

Where do leptospirosis infections normally originate? How are they treated?

Answer 18

Rodent reservoirs and wallows - Antibiotic medication (streptomycin and tetracyclins)

Question 19

How do leptospirosis infections spread?

Answer 19

In the urine - Enter via mucous membranes

Question 20

What can be tested for in foetus that have been aborted after 70 days of gestation? Why?

Answer 20

Parvovirus antibody, Leptospira bratislava antibody and Swine influenza antibody - The foetus becomes immunocompetant so antibodies signify challenge in utero

Question 21

A sow has just aborted, what can be used to test the foetus? What does it test for?

Answer 21

VLA Porcine Abortion Kit - Swine influenza, Erysipelas, Parvovirus, PRRS, Leptospira

Question 22

What is SMEDI? What causes it?

Answer 22

Stillbirth - Mummification - Embryonic Death - Infertility

Porcine parvovirus

Question 23

What can be done to control Porcine parvovirus?

Answer 23

Vaccination - 8 weeks before service then 2 weeks before for subsequent boosters

Question 24

What are the main markers that a foetus died pre-partum?

Answer 24

Sunken blue cornea - Stained skin - ‘Slippers’ on feet - Long autolysing umbilicus - Variable autolysis of organs

Question 25

What are the main markers that a foetus died intra-partum?

Answer 25

Bulging eyes - Meconium in mouth, nostrils and trachea - ‘Slippers’ on feet - Long wet umbilicus - Oedema of organs

Question 26

What are the main markers that a foetus died post-partum?

Answer 26

Meconium in posterior gut - Inflated lungs - Short dry umbilicus - Autolysis of organs

Question 27

When a sow aborts, what is important to attain from the sow and why?

Answer 27

Blood sample - Good to have a reference point in case anything changes

Question 28

How would you estimate the approximate gestation age of an aborted foetus?

Answer 28

Age (days) = 21 + [3 x crown to rump length (cm)]

Question 29

A litter is aborted where the foetuses all died at different gestational periods, where was the infection likely to originate?

Answer 29

In-utero

Question 30

What causes primary uterine inertia?

Answer 30

Lack of uterine contractility or tone

Question 31

What is secondary inertia? What causes it?

Answer 31

Sow is straining but to no effect - Obstruction

Question 32

What can cause a downer sow?

Answer 32

Lactation osteoporosis (fractured pelvis/femur) - Muscle weakness - Apophysiolysis (dislocation) - Rupture of lesser trochanter

Question 33

What is agalactia?

Answer 33

Failure to let down milk

Question 34

There is a sow who is anorexic and has pyrexia, the piglets are very noisy and seem unhappy. Upon physical examination the udder is hot and swollen. What is wrong?

Answer 34

Coliform mastitis

Question 35

What bacteria cause coliform mastitis?

Answer 35

Coliform bacteria - Pseudomonas - Enterobacter - Citrobacter - Morganella (most common = Klebsiella and E.coli)

Question 36

How do you treat coliform mastitis in sows?

Answer 36

3-5 day course of antibiotics (potentiated sulphonamides) - NSAIDs

Question 37

When does pyogenic mastitis generally occur? Why is it bad?

Answer 37

Weaning or end of lactation - Total loss of milk production