Swine (ANISCI EXAM #2)

birthing process

farrowing

newborn

piglet

young female (not yet farrowed)

gilt

mature female (has farrowed)

sow

castrated male

barrow

mature (intact) male

boar

pig between weaning and finishing

feeder pig

pig ready for processing (240-300 lbs)

market hog

global work production

swine is the world’s 2nd most dominant meat producing species

#1 - China

#2 - E.U

#3 - U.S.A —> produced ~11% of the world’s pig meat in 2024

U.S Swine Industry

• one of the world’s top 5 exporters of pork

  • primarily to Mexico, Japan, Hong Kong, China, Canada

• exports avg 20-30% of commercial pork production

• imports pigs/pork from Canada and Denmark

why do consumers like pork?

• price

• lipid level → correlated with tenderness of meat

U.S Swine Industry - how many?

sept 2024: 6 mil breeding animals + 70 mil market hogs

• 76.5 million total pigs

U.S Swine Industry - where?

most U.S swine are raised in the corn belt

• midwest —> Minnesota, Iowa, north caroline

• where most corn is produced

Feral Swine Population

2022 → 6 million feral pigs

prominent in the south

farm size?

most farms have <100 pigs

2.2% of farms have 75% of pig population

Trends in U.S Swine production

• most farms have <100 pigs → 82% of farms

• most pigs are on farms with >5,000 pigs → 82% of pigs

• increasing number of large, corporate-owned swine farms

• increasing vertical integration

• decreasing pasture use and manual labor

• increasing confinement, automation, and use of technology, AI, robotics, and sensors

• increasing individual animal productivity

  • feed efficiency

  • > litters/sow/year

  • > piglets weaned/litter

Swine Management Goals

optimize productivity and product quality

minimize environmental impact (waste and odor)

optimize animal welfare and health

minimize production costs

phases of production

breeding →gestation →farrowing →nursery → grower→ finisher

breeding

sows, gilts, boars

no seasonally polyestrous (year round)

gestation

114 days

3 months, 3 weeks, 3 days

farrowing

born at 2-3 lbs

nurse to wean at 10-15 lbs by 3 weeks of age

nursery

fed corn/soybean meal

• grow to 50-60 lb by 2-3 months

grower

fed soybean/corn meal

grow to 125-150 lb by 4 months

finisher

fed corn/soybean meal

grow to market weight (275-300 lbs) by 6-7 month

how long does it take to go from birth to market?

180-190 days

swine operations

1) farrow-to-wean

2) feeder pig finishing

3) farrow-to-finish

4) purebred/seedstock

5)

farrow-to-wean operations

breeding herd (sows, boars or artificial insemination) produces:

• early weaned pigs (10-15 lbs) at 3 weeks

• feeder pigs (35-50 lbs) by 2 months

finishing operation

feeder pigs (range from 30-90 lb) are purchased and then grown to market weight

farrow-to-finish operation

a breeding herd is maintained to produce piglets that are raised to market weight on the same farm

purebred or seedstock operations

similar to farrow to finish but the end product is breeding boars, gilts, or show pigs → may be purebred or controlled crossbreds

• produce foundation stock/seed breeders for showing or for cross breeding systems

• <1% of total hogs raised in the U.S

seedstock operation breeds

berkshire: carcass quality

duroc: growth rate

landrace: large litter size, mother ability

spotted: large frame, growth rate

chester white: maternal ability

hampshire: muscularity, leaness

poland china: large size, muscularity

yorkshire: large litter size, mothering ability, growth rate

vertical integration

one company (or owner) owns 2 or more stages of production normally operated by separate companies/owners

ideal environment temp + temp range

newborn: 95 F → 90-100 F

3 week old: 85 F → 75-85 F

nursery (12-30 lbs): 80 F → 75-80 F

nursery (30-50 lb): 75 F → 70-80 F

grower-finisher: 60-70 F → 50-75 F

gestation sows + boars: 60-65 F → 50-75 F

lactating sows: 60 F → 50-70 F

flooring options

solid →concrete, wood

• inexpensive

• regular cleaning (labor)

  • ± bedding

totally slotted → concrete, steel, aluminum, plastic, wood

• minimizes manure handling

• expensive, harder to control temp, harder on feet and legs

partially slotted

• one section of the floor slotted, one section solid

ventilation systems

1) provide oxygen

2) remove excess moisture

3) remove dust

4) remove noxious gases → ammonia, carbon dioxide, hydrogen sulfide, methane, carbon monoxide

ventilation and heating/cooling systems must be well maintained for both animal and human safety

water

water analysis semi annually

• salinity, pH, turbidity, coliform count, pesticides, heavy metals, hardness

waterers → check daily

• correct number per group

• correct height by weight

• correct flow rate/pressure

sow productivity

high repro rate = success of swine operations

• litter size

• piglets weaned per litter

• 21 day litter weight

• # litters/sow/year

gilts - breeding

1 estrus at 5-8 months

breed at 2 or 3rd estrus cycle → will get more piglets

• 8 months

• 250-260 lbs

non seasonally polyestrous

total estrous cycle: 21 days

• proestrus: 3-4 days

• estrus: 40-60 hours

• diestrus: 14 days

boars - breeding (dangerous)

puberty: 5-8 months

• improve until 18 months then constant until 4 years

age matters:

• young boar

  • handmate - 1x/day

  • pen breed - 8-10 gilts over 4 weeks

• mature boar

  • handmate - 2x/day

  • pen breed - 10-12 gilts over 4 weeks

inducing puberty in gilts

expose gilts to boar

• olfactory, auditory, and/or visual contact starting at 150 days of age will hasten puberty by 40 days

breed

• certain breeds (duroc & yorkshire) reach puberty later than others (landrace)

• cross bred gilts reach puberty earlier than purebreds

housing

• delay puberty if alone, in small groups less than 3, or in large groups bigger than 30

• pens of 6-12 gilts inside are ideal for puberty at 6 months

• free range housing may favor early puberty

climate

• heat, long days and/or poor air quality will inhibit puberty

stress

• changing social contacts (mix pens) and transportation will induce puberty

pen breeding

house gilts/sows with an appropriate number of boars in a pen or on pasture

remove pregnant gilts/sows

rotate boars every day, every week, or every 25 days

hand mating

heat detected SID or BID, starting a puberty for gilts or 3 days post weaning for sows

supervised exposure to a boar (25 minutes

artificial insemination

heat detect and breed

• 67% of all market hogs

• 90% of hogs from farms with >500 sows

flushing

increasing the amount of feed 10 days before breeding in order to increase ovulation rate

how many days post weaning is the sow back in estrus?

4-7 days post weaning

how can you tell that a sow is ready to breed?

standing reflex, interest in boar, vocalization, swelling/red vulva

back pressure test

boars secrete pheromones which elicit the standing reflex in sows and gilts

• pressing on the sows/gilts back and them not moving (ready for boar to mount them)

this tests for the standing reflex

if a sow does not conceive, when will she return to estrus?

21 days (range: 18-24 days)

how many sows are bred within 7 days post weaning?

more than 95%

why? to limit nonproductive sow days

in commercial herd, 5-30% of sows are culled for failure to return to estrus after weaning

sow production benchmarks

deliver 2.2 litters/sow/year →deliver 4 litters before replace by a gilt

>85% farrowing percentage = # of females farrowing / # females bred

> 24 piglets weaned/breeding female year

pig feed

60-70% of the total cost of production

formulated around cereal grains

• energy: corn, milo, barley, wheat

ground/pelleted → too fine causes ulcers

add protein (soybean meal, meat & bone meal)

add vitamins (A, D, E, K, & B)

add mineral (calcium & phosphorous)

pre farrowing care

vaccinate: 4-6 weeks and 2 weeks before farrowing

de-worm + de-lice: 2 weeks before farrowing

• wash sow

• provide warm, dry, draft free environment

• move to new housing 1-7 days before farrowing

housing options for pregnant sows

• gestation crates

  • locked in for entire pregnancy

• free access gestation crates

• group housing in pens

• outdoor/pasture

• farrowing crates: from 7 days before to 21-28 days after farrowing (~1 month)

  • to prevent sow from crushing piglets

stages of farrowing

1) preparation

2) piglet delivery

3) placenta delivery

piglet delivery

uterine & abdominal contractions → piglet by 15 minutes

normal interval of 15-20 minutes between piglets

• beware of 1 hour between piglets

gilt = 9.5 piglets in 1st litter (increase by 0.5 piglet/litter)

sow > 10 piglets per litter

normal total delivery time = 2-3 hours

placenta delivery

30 mins - 12 hours after last piglet

retained placenta if greater than 12 hours

after farrowing

• ensure breathing

• dip umbilicus

• ensure nursing & colostrum intake within 4-6 hours

maternal recognition of pregnancy

each uterine horns must contain at least 2 piglets each (total of 4 piglets) to signal to sow that she is pregnant and to prevent regression of corpus luteum by prostaglandin F2a

induced (synchronize) farrowing

why?

• allows for close supervision during farrowing

• groups sows for weaning and rebreeding

• improves use of labor and facilities

• allows for cross fostering if necessary (one sow has more piglets but not enough teats, piglets given to sow who has less piglets)

how?

• prostaglandin F2a injection to sows on day 112 → causing sows to farrow in 24-36 hours

• ± oxytocin injections 24 hours after the prostaglandin injection → sows farrow within 6 hours

  • risk of oxytocin: premature placental separation leading to dead piglets

ex. inject sows >111 days pregnant with prostaglandin F2a on Thursday morning

• ± inject sows with oxytocin on friday morning

pre-weaning mortality

roughly 1/3 of pre-weaning deaths occur in the first 72 hours

stillbirths: should be less than 5-7% of total piglets born

hypoxia: premature rupture of umbilical cord

chilling: environmental temp needs to be 85-100 F, anything less than that leads to chilling

• have heat lamp, brooder, creep area

crushing: most common cause of death in the first 3 days

low birthweight: 30-40% of piglets weighing <2 lbs at birth will die during the first 3 weeks

starvation: runt piglet or sow lactation

• 2nd most common cause of neonate death

diarrhea/scours: bacteria + viruses (4th)

respiratory diseases (5th)

Weaning

age: determined by nursery facilities/management

@ 2-5 weeks (most wean at 3 weeks)

@ > 10-12 pounds

stressful

loss of maternal antibody protection by ~3 weeks

segregated early weaning (SEW)

piglets are weaned at 21-22 days

piglets moved into an isolated, clean nursery then into a finisher building (no contact with other groups)

temp for weaned piglets = 85 F then drop slowly to 70-75 F

grower & finisher housing

60-70 F

group by weight → within 20% of the average

20-50 pigs/pen or pasture

• 1 waterer per 20-25 pigs

• 1 feed space per 4 pigs

grower ration: corn/soybean meal (16-18% protein, 1.4 - 4 lbs per day)

finisher ration: corn/soybean meal (12-14% protein, 6-10 lbs a day)

Pig carcass + retail cuts

~28% of the pig’s weight is lost during slaughter and dressing

• removing blood, hide, viscera etc

carcass is hung on a rail and placed in a cooler for chilling

20% more weight is lost during preparation of retail cuts

• as bone, fat and moisture

how to calculate dressing percentage

dressing % = carcass weight/live weight x 100

vaccinations

pigs should be vaccinated before they are likely to encounter an infectious organism because it takes about 10-21 days after vaccination for a pig to mount a protective immune response

• exact time depends on pig’s age, the vaccine, and if the pig has been vaccinated before

pre-breeding vaccinations → gilts, sows, boars

• repro: parvovirus, leptospirosis, PRRS, erysipelas

pre-farrowing vaccinations → gilts and sows

• repro, respir-, gastrointestinal

young pigs (nursing piglets or later + boosters)

• mycoplasma, PRRS, AR, TGE, pseudorabies

at weaning → sows

• leptospirosis, parvovirus

at weaning → piglets

Vaccine: Parvovirus, PPV

Disease: SMEDI (stillborn, mummy, early embryonic death, infertility)

• endemic in most herds

transmission: ingestion, inhalation, breeding & transplacentally (in utero)

infected at < 30 days → embryonic death + resorption

infected at 30-70 days → sequential death; mummies & stillbirths

infected at > 70 days → fetal immune response & some live piglets

• the later the sow gets infected in pregnancy, the higher the chance there are some live piglets

• RARELY ABORTION

vaccine: leptospirosis

disease: bacterial spirochete → zoonotic

CONTAGIOUS:

• shed in urine by pigs and other animals (rats, mice, skunks, racoons)

• can be present in contaminated water

transmission: spread via ingestion, penetration through mucous membranes or skin, breeding and transplacentally (in utero)

results: sepsis & localization to an organ

• uterus: abortion, stillbirth, mummies, weak piglets, small litter

• kidneys: flu-like symptoms & kidney diease

treatment: antibiotics + vaccinate

vaccine: colibacillosis

disease: E. coli ( in almost everything)

• diarrhea

Vaccine: Erysipelas

subclinical shedder:

• ingest bacteria or infected through a cut

• localize to tonsils

• shed in feces & oronasal secretions

acute illness:

oronasal exposure → septicemia →localizes

• fever (104-108 F)

• joints = lameness/arthritis

• skin = diamond skin disease (cyanosis)

• uterus = abortion (any stage); mummies

• ± death

treatment: antibiotics

chronic illness:

• joints = lameness/arthritis

• heart = endocarditis

treatment: antibiotics/euthanasia

African Swine Fever

virus = fever, poor appetite, weakness, pink/blue skin, diarrhea, pain, respiratory signs (cough), abortion, neurologic signs, ± death

tranmission:

• direct contact with infected pigs (blood, oral + nasal discharge, urine, feces)

• blood sucked insects (ticks)

• indirect contact with fomites (boots, food, pork product etc)

preventing African Swine Fever

1. limit on farm traffic

2. teach prevention practices regularly

3. shower in/shower out

4. wear clean coveralls and boots at each site

5. keep pigs from trash and no eating near animals

6. wash all on farm equipment and vehicles

7. keep pigs away from wildlife

pot bellied pigs

birthweight: 0.5-0.75 lb

adult weight: 90-220 lb (rarely up to 300 lbs)

lifespan: 10-18 years

piglets should be socialized when young (<8 weeks of age)

pot bellied pigs - behavior

• clean → differentiate between sleeping, eating, and toilet areas

• only have a few sweat glands, so they wallow in water or mud for cooling

• herd animals, so will fight to establish a hierarchy

• wag their tags and vocalize to express emotion

• love to root and nest → they are omnivores

• should be provided with environmental enrichment

pot bellied pigs - diet

feed an amount of feed equivalent to 2% of their body weight per day in dry matter

• will over eat so don’t overfeed or they will become obsessed and suffer from health problems

• have a sweet tooth and prefer foods flavored with sucrose, glucose, lactose or saccharin

  • avoid sweet treats

  • healthy snacks: carrots, celery, broccoli

pot bellied pigs - repro

spay/ovariohysterectomy

• based on weight >15 lbs (around 3-4 months)

• based on age (around 4-6 months)

castrate

• based on weight 5-10 lb

• based on age (1-4 months)

pot bellied pigs - day of beauty

1) trim hooves

2) clean ears

3) trim husks/canines

4) bathe