Service management and the dry sow Flashcards
What are the major issues of infertility on pig farms?
- 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
How long is the reproductive cycle of pigs?
21 days
normal = 19-23
Where is semen deposited in the reproductive tract?
Cervix
What are the functions of a pigs reproductive anatomy and physiology?
- 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
If one ovary is working how are piglets distributes in the uterus?
Even if only one ovary is working, embryos will be distributed through both uterine horns by myometrial contractions
Describe the physiology of weaning
- No sucking stimulus
- Pituitary isn’t stimulated – no prolactin secretion
- Positive feedback on gonadotropins
Describe the interactions of the sow which can influence her throughout reproduction
- 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
Describe appropriate light levels for pigs
- 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.
Which features of a sows housing and environment need to be considered on farm
- Wean-Service Interval vs pregnancy
- Types/space
- Temperature/ventilation – keeping them cool is harder
- Water/feed
- Bedding/hygiene
- Social groups/run outs
- Nutrition - BCS
Describe BC scoring pigs
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
Describe how the feed intake of pigs changes throughout her reproductive cycle
- 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
What are the uses of boars?
Production of sperm
Stimulus for sow
Describe the main features of a boars reproductive anatomy
Spiral penis
Accessory glands – produce a large amount of fluid
Is sperm fresh or frozen in the pig industry?
All sperm is fresh
Describe the importance of timing service
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
How long after the start of true heat will a sow ovulate?
38-42 hours
Describe boar stimulation to females and how this is replicated during AI procedures
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
How are myometrial contractions involved in service?
- 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
Describe how semen for AI is stored
Semen delivery/storage – fresh – kept at 17 degrees at all time
Needs to be turned twice a day, do not shake!
List the signs of heat shown by sows in oestrus
- 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
What are the 3 fates of semen post insemination?
2/3 = phagocytosis
1/3 = reflux
Very small % = reach oviduct
Compare regular vs irregular returns
Regular return – something has happened at fertilisation
Irregular return – fertilisation has occurred but something has occurred afterwards
What is worker fatigue and how can it be limited?
Farrowing rate % decreases and the number of sows per operator increases
List the main features of a good AI area
- 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
On average the number of piglets born alive is highest at which parity in pigs?
4th
What are the considerations of reproductive issues on pig farms?
- 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!
What basic questions should be asked when there are reproductive issues on pig farms?
- 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)
How is overall reproductive production assessed on farm - i.e. what is the target?
Overall production is measured by pigs born alive / sow / year
This includes born alive / sow and litters / sow / year (farrowing index)
List some factors that influence the number of piglets born alive
Point of ovulation
Point of fertilization
Ability to implant
Ability to maintain through pregnancy
Survival through farrowing
List some factors that influence the farrowing index
Conception rate
Final farrowing rate
Weaning to service gap
Weaning to actual conception gap
Other causes of empty days
How can you narrow down the cause of reproductive issues on pig farms
- 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)
What are the three main differentials for reproduction issues on pig farms?
- Managemental (first step) – i.e. non-infectious
- Infectious causes - Something new? Recurrence of something old?
- Random cause / unlucky period
List some non-infectious cases of reproductive issues in pigs
- 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
List some infectious cases of reproductive issues in pigs
- Porcine parvovirus
- Porcine Reproductive & Respiratory Syndrome (PRRS)
- Porcine Circovirus 2 (PCV2)
- Swine Influenza
- Leptospirosis
- SMEDI viruses
- Aujeszky’s
- Classical Swine Fever
- Brucella suis
How may conceptions issues lead to reproductive problems in pigs
- 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)
If a sows regularly returns to service (multiple of 21 days- common) due to a reproductive problem, what may have happened?
- 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)
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?
- 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)
Which diagnostics can be used in porcine reproductive problems?
- Blood samples (difficult to interpret – paired?)
- Abortion materials (difficult to obtain (eaten) – contamination)
- Swabs (value questionable)
- Maternal tissues
Describe endometritis in pigs - and when it can occur in the cycle?
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
How are reduced litter sizes investigated?
- 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))
What are the causes of implantation disruption in sows?
- Stress is the biggest issue
- Nutrition
- Seasonal influence
- Disease (localised – systemic)
- Once day 30 is reached, most pregnancies are more robust
List some causes that influence the number of piglets born alive/abortions in pigs
- Stress
- Parvovirus, PRRS, PCV2
- Erysipelas
- Leptospirosis
- Aujeszky’s / CSF
- Toxaemia (endotoxins – plants – mycotoxins)
- These will also influence born mummified at farrowing
What methods are used on farm to address and manage reproductive issues on farm?
- 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)
