Service management and the dry sow

Question 1

What are the major issues of infertility on pig farms?

Answer 1

• The majority of problems are managemental
• Difficult to accept on farm, hence it ‘must be infectious’
• Beware the search for a causative ‘bug’ – this will often prove fruitless, or create confusion…
• We must understand the basic principles, analyse the problem, and reach conclusions based on the evidence

Question 2

How long is the reproductive cycle of pigs?

Answer 2

21 days
normal = 19-23

Question 3

Where is semen deposited in the reproductive tract?

Answer 3

Cervix

Question 4

What are the functions of a pigs reproductive anatomy and physiology?

Answer 4

• Prepare and deliver an egg ready for fertilisation
• Allow optimum conditions for fertilisation to occur
• Allow and control development and growth of the piglets
• Protect the piglets
• Deliver the piglets to the outside world

Question 5

If one ovary is working how are piglets distributes in the uterus?

Answer 5

Even if only one ovary is working, embryos will be distributed through both uterine horns by myometrial contractions

Question 6

Describe the physiology of weaning

Answer 6

1. No sucking stimulus
2. Pituitary isn’t stimulated – no prolactin secretion
3. Positive feedback on gonadotropins

Question 7

Describe the interactions of the sow which can influence her throughout reproduction

Answer 7

• Humans: decrease stress (cortisol)
• Boar: pheromone stimulus - heat
• Hygiene/security: infections getting into the cervix
• Social: hierarchy, bullying
• Housing, Feed, Temp (eat less when too hot)
• Light

Question 8

Describe appropriate light levels for pigs

Answer 8

• 30 lux is the legal minimum.
• 200 lux is a good stimulus. Also need a dark period
• Pigs don’t have red receptor cones so orange lighting is not a good stimulus.

Question 9

Which features of a sows housing and environment need to be considered on farm

Answer 9

• Wean-Service Interval vs pregnancy
• Types/space
• Temperature/ventilation – keeping them cool is harder
• Water/feed
• Bedding/hygiene
• Social groups/run outs
• Nutrition - BCS

Question 10

Describe BC scoring pigs

Answer 10

1 = emaciated, backbone very prominent
2 = thin, backbone prominent
3 = ideal condition during lactation and weaning, backbone just palpable
4 = slightly overweight, cannot find the backbone
5 = body rotund, over fat

Question 11

Describe how the feed intake of pigs changes throughout her reproductive cycle

Answer 11

• Very big drop in feed intake between weaning and service , can impact ovulation
• Feed intake plateaus following service until later in pregnancy - affects implantation and sows body condition
• Feed intake begins to increase towards the end of pregnancy -> directly impacts piglets birth weights

Question 12

What are the uses of boars?

Answer 12

Production of sperm
Stimulus for sow

Question 13

Describe the main features of a boars reproductive anatomy

Answer 13

Spiral penis
Accessory glands – produce a large amount of fluid

Question 14

Is sperm fresh or frozen in the pig industry?

Answer 14

All sperm is fresh

Question 15

Describe the importance of timing service

Answer 15

Timing – make sure she is in standing heat
- Ovulation takes place 2/3 into her standing heat - ideal time to serve is just before she ovulates
- Hard to know how long she will be in oestrus
- Late standing heat indicates poorer fertility
- Sperm has a short lifespan so may need to be served twice

Question 16

How long after the start of true heat will a sow ovulate?

Answer 16

38-42 hours

Question 17

Describe boar stimulation to females and how this is replicated during AI procedures

Answer 17

Remember that you have to make her believe that she is being mated by a boar and give her the same amount of stimulation in 5 minutes as he would give her in 30 minutes…
1. Teat Stimulation - Rub along mammary glands (boar nosing)
2. Back & Shoulder Pressure - Pretend you weigh 250kg (boar mounting)
3. Side & Flank Pressure - Either you or using a raddle (boar leg position)
4. Groin Manipulation - Pull into her groin/crus towards the ovaries (boar nosing)
5. Vulval Stimulation - Apply pressure to vulval lips (boar nosing & service)
6. Catheter Manipulation - Gentle movement (boar service)
7. Vocalisation - Talk to her (boar vocalisation)
8. Boar pheromones

Question 18

How are myometrial contractions involved in service?

Answer 18

• Moves the semen from the cervix to the oviduct
• Will only happen if they sow is stimulated
• Be aware that gilts will take longer and will need more stimulation

Question 19

Describe how semen for AI is stored

Answer 19

Semen delivery/storage – fresh – kept at 17 degrees at all time
Needs to be turned twice a day, do not shake!

Question 20

List the signs of heat shown by sows in oestrus

Answer 20

• Vulva: reddening, swelling, mucous
• Vocalisation
• Interest in boar
• Flank nosing
• Smelling of boar
• Standing next to boar
• Standing to back pressure
• Allowing sows or boar to mount

Question 21

What are the 3 fates of semen post insemination?

Answer 21

2/3 = phagocytosis
1/3 = reflux
Very small % = reach oviduct

Question 22

Compare regular vs irregular returns

Answer 22

Regular return – something has happened at fertilisation
Irregular return – fertilisation has occurred but something has occurred afterwards

Question 23

What is worker fatigue and how can it be limited?

Answer 23

Farrowing rate % decreases and the number of sows per operator increases

Question 24

List the main features of a good AI area

Answer 24

• Close to sows
• Not near boars
• Nose to nose contact
• Individual insemination pen
• Undisturbed area post insemination
• Flow of pigs
• Good gates/dividers
• Storage facilities
• Light
• Rubbish disposal
• Protection

Question 25

On average the number of piglets born alive is highest at which parity in pigs?

Answer 25

4th

Question 26

What are the considerations of reproductive issues on pig farms?

Answer 26

- Chronic infertility will always be more difficult to correct - Infertility issues can ‘just’ appear - Cause is not always obvious - Can just resolve with time, despite interventions - ‘Problem’ farms exist!

Question 27

What basic questions should be asked when there are reproductive issues on pig farms?

Answer 27

- Is this a whole group or individuals? - Are there differences between parities / groups? - Has it happened previously? - What have they tried treatment-wise? - Any changes on farm? (staff, pig flow, feed regime, environmental) - Any changes from suppliers? (semen, feed, gilts / boars)

Question 28

How is overall reproductive production assessed on farm - i.e. what is the target?

Answer 28

Overall production is measured by pigs born alive / sow / year This includes born alive / sow and litters / sow / year (farrowing index)

Question 29

List some factors that influence the number of piglets born alive

Answer 29

Point of ovulation Point of fertilization Ability to implant Ability to maintain through pregnancy Survival through farrowing

Question 30

List some factors that influence the farrowing index

Answer 30

Conception rate Final farrowing rate Weaning to service gap Weaning to actual conception gap Other causes of empty days

Question 31

How can you narrow down the cause of reproductive issues on pig farms

Answer 31

- Have we got a conception problem? (returns – regular or irregular) - Have we got too few piglets being born? (total born reduced – abortions) - Overall production is too low? (herd is not performing)

Question 32

What are the three main differentials for reproduction issues on pig farms?

Answer 32

- Managemental (first step) – i.e. non-infectious - Infectious causes - Something new? Recurrence of something old? - Random cause / unlucky period

Question 33

List some non-infectious cases of reproductive issues in pigs

Answer 33

- Nutrition - Stress: physiological, behavioural, heat, cold - Don’t vaccinate during this period - Quality of service & implantation period - Staff factors - Seasonal infertility - Herd profile - Sunburn / sensitisation: pain when touched on their back so don’t stand in heat - Mycotoxins - Sow / boar illness – lameness

Question 34

List some infectious cases of reproductive issues in pigs

Answer 34

- Porcine parvovirus - Porcine Reproductive & Respiratory Syndrome (PRRS) - Porcine Circovirus 2 (PCV2) - Swine Influenza - Leptospirosis - SMEDI viruses - Aujeszky’s - Classical Swine Fever - Brucella suis

Question 35

How may conceptions issues lead to reproductive problems in pigs

Answer 35

- Have they been served? (anoestrus – silent heat – not seen) - Gilts: often poorly observed (age / weight / heat balance) (genetic – intersexuality – abnormal anatomy) - Sows: (energy balance – stress – lactational oestrus – seasonal –mycotoxins)

Question 36

If a sows regularly returns to service (multiple of 21 days- common) due to a reproductive problem, what may have happened?

Answer 36

- Fertilisation has failed to occur (timing of service – quality of service – boar contact post AI service – boar problem – semen problem) - Early loss of embryos (has to be very early – incomplete involution – stress – nutrition – infection)

Question 37

If a sows irregularly returns to service (out of sync (<19d; 24-37d; 47-56d) - Less common ) due to a reproductive problem, what may have happened?

Answer 37

- Have they actually been in-pig? Observation important and ultrasound PD is valuable - Loss of pregnancy (embryo loss >12d – abortion) - Infection (tracking endometritis – repro specific)

Question 38

Which diagnostics can be used in porcine reproductive problems?

Answer 38

- Blood samples (difficult to interpret – paired?) - Abortion materials (difficult to obtain (eaten) – contamination) - Swabs (value questionable) - Maternal tissues

Question 39

Describe endometritis in pigs - and when it can occur in the cycle?

Answer 39

If bacterial in nature, hygiene is important Cervix only open at two points of the cycle: - Service hygiene (boar vs AI) - Post service hygiene - Farrowing hygiene

Question 40

How are reduced litter sizes investigated?

Answer 40

- Is it a herd problem, or a group, or individuals? - Ovulation issue (genetics, nutrition, age, parity structure) - Fertilisation issue (service timing, service quality, boar / semen issue, nutrition, stress (before / during / after))

Question 41

What are the causes of implantation disruption in sows?

Answer 41

- Stress is the biggest issue - Nutrition - Seasonal influence - Disease (localised – systemic) - Once day 30 is reached, most pregnancies are more robust

Question 42

List some causes that influence the number of piglets born alive/abortions in pigs

Answer 42

- Stress - Parvovirus, PRRS, PCV2 - Erysipelas - Leptospirosis - Aujeszky’s / CSF - Toxaemia (endotoxins – plants – mycotoxins) - These will also influence born mummified at farrowing

Question 43

What methods are used on farm to address and manage reproductive issues on farm?

Answer 43

- Identify the areas to address (weaknesses – groups – corrections) - Altered techniques / interventions (medication? – hygiene – training) - Possible herd stabilization (pig flow – exposure – vaccinations) - Control infections (vaccination – PPV, PRRS, Ery (Lepto) - Strategic medication – Lepto, endometritis) - Gilts (introduction – age, condition, puberty, exposure, synch) - Sows (lactation issues, lameness, age) - Parities (ideal parity structure – 2nd litter drop) - Semen issues (boars vs AI)