swine exam 2 Flashcards
maternal pig breeds
landrance, large white
(selected based on litter size and mothering ability)
paternal pig breeds
: pietrain, duroc, Hampshire, white synthetic
-: selected for growth, feed efficiency, carcass and meat quality.
pigs gestation
114-117 days
4 stages of production and times
- Breeding/gestation: gestation 114-117 days
n Farrowing: where sows furrow and nurse there litters 3-4 weeks
n Nursery: where weaned pigs are raied 5-8 weeks
n Grow-finish: where pigs are raised after nursery before slaughter 16-18 weeks.
feeder vs market pig sizes
n Feeder pig – a pig old enough to enter the grower barn (25kg)
n Market pig – a pig large enough to be processed
n 115-125 kg live weight, 5-6 months of age
production flow of pig barns and times
-gilt development -> breeding and implatation (35 days)–> gestation 12 weeks–> farrowing 4 weeks.
-sow goes back to breeding and implantation barn. then piglets taken to nursery (6-8 weeks) where they are raised until old enough to go to grower-finisher barn until they go to slaughter. 16 weeks
humane slaughter process
-delivery to plant by producer, traceable with tattoo on L shoulder which identified each farm.
n Assembled put together in “yard” for 12-18 hours
n Stunned by electrocution or C02
n Shackled
n Exsanguinated (via vena cava/jugular)
n Scalded, dehaired & washed
n Eviscerated
n Inspected, weighed
n Halved & chilled
pig flow systems continous flow or all in all out
-continuous flow system: can lead to disease, all sharing air. Coming into contact with new piglets and older and younger animals. dynamic pop.
-All in all out system: piglets are weaned and stay together as a group with the same immunities ect. So we don’t have sharing of pathogens at the wrong time. static pop.
5 freedoms for assesing pig housing
1 freedom of movement
2 freedom from aggression
3 control over individual feed intake
4 provision of environmental encrichment
5 provision of static space requirements
lighting in pig barns
-pigs are seasonal breeders farrow in spring
-stimulated by shortening photoperiod
-most fertile in autum to winter
-seasonal infertility in summer
-16 hours day light to attempt to prevent seasonal infertility
barn temp breeding
◼ “Effective” vs. “ambient”
◼ Optimum 16-18oC (range 10-27oC)
◼ Warmer temperature required in stalls due to inability to escape adverse air flow
and/or floor moisture
◼ Pregnant sows are prone to heat stress (sweat glands on nose only)
◼ Drip nozzles & misters can be useful if increased airflow to create evaporative
cooling is provided
◼ Regions of prolonged hot summers
breeding gilts
Advantage of delaying breeding
Litter size increases by about 0.5 pigs for each subsequent estrus
(E1, E2, E3) but must be balanced by additional housing and feed
◼ Common guidelines for first fertile breeding on commercial farms:
◼ Minimum 220-240 days of age
◼ Second observed estrus on farm, skip first estrus
◼ Optimum weight (~135 kg)
how is breeding done
◼ Typically estrus cycle occurs 4-7 days after weaning
◼ Confirm receptivity to boar visenctimized boar goes around and stimulates sows.
◼ Inseminate or breed naturally once per day until out of standing heat (generally 2-3 matings total)
semen production
◼ AI stud or on-farm
◼ CFIA regulated
◼ Fresh, 16-17oC storage, protected from UV light
◼ Usually pooled (collections from multiple boars combined)
◼ 2-3B sperm/dose, 2-3 doses per female
◼ Many extenders with shelf-life 3-14 days
◼ Sexed semen now commercially available through 1 supplier
confirming preg
◼ Estrus (heat check) with boars at day 21 & 42 (best way with good staff)
◼ Pregnancy examination day 25-35 depending on equipment
Non-pregnancy
◼ Conception failure – return to service at 21 (+/- 3) day intervals
- Regular returns (18-21, 39-45 d) no conceptus recognition not pregnant
◼ Pregnancy failure – after maternal recognition of pregnancy
life cycle of sow
: vaccinated pre breeding, during gestation vaccinate ecoli, right before parturition vaccinate sow for parvo, lepto which gives passive immunity to the piglets.
P1 sow lactates 21-28 days. WSI = weaning to service interval
pre farrowing procedures
Vaccinate dam:
n Protection of post-natal litter
n Enhance colostrum quality and passive immunity
n Lactational IgA and IgG (re- secreted)
n Transfer sows to farrowing room at gestation D110-112
n Reduce feed intake when farrowing is imminent
n Scrape manure behind sows daily
n Raise room temperature to 21-23o C for farrowing
fetal cortisol
-peaks rapid 48 hr pre term
-needed to induce farrowing and mature fetal liver (glycogen so piglets have energy to survive), lung (surfactant production) and maturation of skeletal muscle.
Parturition time and signs
-4.5 hours, piglets every 25 mins
placenta expelled after last piget
-Signs of impending parturition
n Secrete milk
n Nesting behaviour, restlessness
n Reduced feed intake
n Raised rectal temp
Enhancing colostrum consumption:
n Split suckle, let first 5 suck then move them and let others suck
n Hand feed (collect, supplement at risk piglets (frozen, fresh)
n Commercial bovine colostrum substitutes (HeadStart™)
Iron administration
Required (every pig):
n Sow’s milk deficient in iron
n Piglets born with limited iron reserves
n No access to iron in soil
n Rapid growth rate of piglets
n Deficiency: clinical anemia
-do before day 4, better before day 2
Product choices: Dextran (100 or 200 mg/mL), Gleptoferrin (200 mg/mL)
Piglet castration
Necessary to contol “boar taint”
n Adverse taste detectable by some people after cooking boar meat
n Taint associated with male hormones: skatole, indole, androstenone
Non-surgical alternative, most pigs are done this way now.
§ Improvest (Zoetis) anti-GnRH vaccine: immunological castration
Fetal mummification (mummies)
Fetuses that die prior to term, but after skeletal calcification begins (~ gestation day 30)
n Inspissated remains of fetal tissues
n Age determined by crown-rump length helps you know at what age of gestation it died.
Many causes:
n Infectious (i.e. PPV, PRRSV)
n Non-infectious (i.e. parity, litter size)
n Size matters -> may provide clues to etiology
Stillbirth piglets (stillborns)
Full term fetuses that are live until term, but die of hypoxia during a prolonged farrowing
Risk factors for stillborns:
n Higher parity
n Over-conditioned (fat)
n Season (summer, heat)
n Higher birth order, less piglets born less tired sow (farrowing fatigue)
Diagnosis: Float lungs to differentiate stillbirth from postnatal death. If they sink stillborn
Why induce sows to farrow?
Potential advantages
n Staff presence at farrowing to facilitate cross fostering & neonatal care
Pregnant sow showing nesting behavior (sign of impending farrowing)
n Reduce stillbirth piglets
n Induce straggler sows over 116 d gestation (maintain AIAO farrowing groups)
Disadvantages
n Risk of premature delivery
n Natural or synthetic prostaglandin F2- alpha: Lutalyse, Planate
piglet immune system
Passive immunity
n Nursery pigs are susceptible to many diseases due to the nature of their immune system
Susceptibility varies among pigs based on:
-wean pigs when most susceptible between passive and active immunity and expose them to stress and maybe other litters.
-if you vaccinate at 2 weeks of age: maternal immuntity will prevent the vaccine from inducing a reaction. Not effective.
sanitation steps
a) Removal of organic matter
B. )bacterial biofilms: removal of microbial community that populates environmental surfaces
c.) Application of disinfectants
Disinfect - many classes and products available:
n quaternary ammoniums, phenols,
Segregated weaning
Segregation of weaned pigs from sows facilitates:
§ Disease control
§ Manure disposal
§ Staff specialization
-on site nursery or off site nursery
Physiologic factors affecting weaned pigs
- GIT development
n Enzymes: lactase, proteases
n Villi health - Weaning age & weaning weight
- Social stresses
n Weaning, relocation, mixing - Exposure to creep feeding
n Provided to some litters
Villi health
Blunting ( loosing villi) causes diarrhea due to malabsorption, after time leads to osmotic darrhea.
Causes of blunting:
n Weaning stress
n Soybean meal hypersensitivity (allergy)
n Starvation/anorexia
n Disease (pathogens such as TGEV, PEDV, rotavirus, etc)
n Environmental stress (chilling)
Weaning age & weight
-weaned in range from 13-26 usually around 16-20 kg
nursery performance targets
exit weight 28-30kg
-ADG 450g/d
-feed gain ration 1.2-1.3
-feed cost 12-15
-mortality <2%
target fat and loin thickness
fat: 14-20mm
loin: 55-70
