16. Swine Biology, model and research

Scientific name of the domestic pig?

Sus scrofa domestica

Berkshire

Chester White

Duroc

Hampshire

Landrace

Pietrain

Poland China

Spotted (Spot)

Yorkshire

Minipig- Sinclair

Melanoma

Minipig- Gottingen

Minipig- Hanford, Hormel

Minipig- Yucatan pig

Most commercial swine used for research are _____ weight and ____ of age. Commercial swine gain ____ of weight during this period.

-15-30kg

-8-12wk

-2-5kg

Generally, projects involving a length of over ____ would best be performed on mini pigs

>3wk

If you have pigs coming from multiple vendors it is recommended to ____

not mix animals

Vendors of pigs should be ____ free and _____ negative

-brucellosis free

-pseudorabies negative

Vendor vaccination and parasite control program should consist of the following:

-deworm piglets every ____

-use ____ ectoparasite treatment

-vaccinate weanlings against ____ and ____

-breeding animals should be vaccinated against ___, ____, ____, and ____

-4-6wk

-preventative

-erysipelas and leptospirosis

-porcine parvovirus, brodetella bronchiseptica, pasturellla multocids, and E. coli

What is the recommended minimum acclimation period for pigs?

Allow animals 72 h acclimation and avoid sudden diet change

-Swine are best housed in ____.

-____ flooring should be avoided

-Flooring should have a ___ surface for traction and wear on hooves

-____ is recommended, but pigs will eat it and that must be taken into consideration when _____ animals

-Watch plastic flooring for ___ because pigs will chew and destroy the rest of the coating

-_______ are ideal for hoof wear

-pens

-wood

-rough

-wood chips, fasting

-tears

-slatted fiberglass floors with grit

Swine will readily drink from automatic watering systems. Water should be checked ____ to ensure delivery and to avoid _____ which can result in neurologic syndrone

-daily

-salt poisoning

Swine should be fed ____ to reduce aggression

-individually

Swine are social creatures and at minimum the cage should provide ___ and ____ contact between animals

-visual and snout

Swine can be restrained using ___ and ____

-panepinto slings

-pig boards

IM injections in pigs should be given in the ___ or ___

neck or hind limb

Venous access can be taken from the ____ (most common), ____, ____, ____, ____, ____, ____, and ____. (8 sites)

-auricular

-cephalic, external jugular, internal jugular, anterior vena cava, lateral saphenous, cranial abdominal (mammary), tail vein, femoral vein

Standard needle size for a swine up to 50kg is ____g and ____ length

20g

1.5inch

Intibuation is performed with the pigs in ____ recumbency using a ____ to lift the tongue and mandible to visualize the vocal cords

-dorsal

-laryngoscope

Cranial vena cava blood collection

left saphenous vein blood collection

femoral vein blood collection

mammary vein blood collection

tail vein blood collection

cephalic vein blood collection

accessory cephalic vein blood collection (large arrow), common dorsal digital vein (long arrow)

auricular vein blood collection

visualization of vocal folds using laryngoscope with animal in dorsal recumbency

Why should blood draw from caudal vena cava (CVC) be on the right side in pigs?

avoid damage to the recurrent laryngeal nerve (branch of vagus)

What are some of the common research uses of pigs?

-Cardiovascular Disease-Atherosclerosis

-nutritional and GI dz (diet similar to humans, omnivorous)

-renal dz (renal hypertension, vesicoureteral reflux, intrarenal reflux, urinary obstruction)

-Teaching

-Surgery (Laparo/endoscopic procedures -similar size and anatomy, swine xenotransplantation, transplantation-heart, lung, liver, kidney, viscera, plastic surgery)

-other (fetal, shock, diabetes, malignant melenoma, malignant hyperthermia, gastric ulceration)

Which pig breed is used to model High membranous VSD (genetic)?

Yucatan

Which pig breed is used to model Von Willebrand's?

Poland-China

What are the two ways to induce Atherosclerosis in pigs? What is the familial model?

-Diet induced with high cholesterol/fat-enhanced diet,

-endothelium damage induced (balloon catheter)

-Rapacz familial hypercholesterolemia model

What are the similarities in pigs makes it a good model for cardiovascular diseases?

-Blood supply from coronary artery is right side dominant

-Does not have preexisting collateral circulation

Similar to 80% of human population

-Aorta has true vaso vasorum (Vasa vasorum-network of small blood vessels that supply the walls of large blood vessels)

What are the cardiovascular dissimilarities in pigs from human?

-Electrophysiological system more neurogenic (requires nervous input to contract) than myogenic (human)

-Left azygous vein drains intercostal vessels into coronary sinus (humans don't have this)

What vessel can be ligated in the pig to provide total coronary venous drainage into the coronary sinus?

left azygous vein

What structure in pigs is involved in closure of pylorus? It's a muscular outpouching of the stomach near the pylorus

Torus pyloricus

Unlike humans, the bile duct and pancreatic duct enter the duodenum ______ in the proximal portion

separately

The mesenteric vessel branches from their vascular arcades into the _____ of the intestine rather than the mesentary as in other species

sub serosa

The majority of the pig large intestine is arranged in a _____ in the ___ quadrant of the abdomen. It includes the cecum, ascending, transverse, and majority of descending colon

-spiral colon

-left upper

___ and ___ are present in the cecum and large intestine

-____longitudinal ribbons of smooth muscle on the outside of the ascending, transverse, descending and sigmoid colons

-____ small, pouch-like structures in the colon that create its segmented appearance. They form due to the contraction of above

-teniae

-haustra

Pig lymph nodes are inverted meaning their germinal centers are on the _____ portion

internal

The thymus is near the ____ instead of proximal to the larynx and has ___ lobes

-thoracic inlet

-fused

Pigs have ____ pair/s of parathyroid glands near the larynx

single

The pig penis is _______ located in a preputial diverticulum near the umbilicus. The penis also has a _____.

-fibromuscular with a corkscrew shaped tip

-sigmoid flexure

What are the male accessory sex glands of the pig?

-prostate, vesicular gland, bulbourethral glands

Female pigs have a ___ uterus, ____ cervix/s, and ____ follopian tubes

-bicornate

-single

-long

Pigs bilobed pancreas encompasses the _____ vein

superior mesenteric

____ system is like that in humans, but many subtle differences exist which may impact toxicity studies

Cytochrome P450

Swine do not require _____ in their diets (unlike ruminants) when adequate ___ and ___ are available.

-elemental sulfur

-methionine and cysteine (sulfur containing amino acids)

____ alone can meet the sulfur needs of swine because cysteine can be synthesized from ____

methionine

The ____ isomer of amino acids are the most biologically active form in swine

L

How many water devices per 10-20 pigs or how many water devices per pen at minimum?

Water (Ag Guide): 1 water device per 10 to 20 pigs or at least two in a pen located apart from each other

What is the recommended housing temperature for pigs according to the guide?

61-81 F

When do pigs reach sexual maturity? mini-pigs?

-Sexual maturity at 5-6 month of age (115-130kg) (later on it says 3-7mo)

-mini-pig: 4-6 month of age

Litter size of domestic pigs? Mini pigs?

-8 to 12

-4 to 6

What kind of breeder is pig?

Polyestrus

How long is the estrus cycle and how long does estrus last? What is the best timing for AI in pigs? How many times should you breed sows during estrus to maximize conception rates?

-Estrus Cycle: 21 days

-Estrus duration: ~48hrs (range 1-3 days)

-Inseminate 12 hr prior to ovulation

-twice

AI is best when sows are inseminated _____ after onset of estrus

10-30hr

_____ mating is where you place sow and boar in same pen at 12 to 24 hour intervals during estrus until the sow is no longer receptive

-hand

What are physical signs of estrus in a pig?

-vulvar reddening & swelling, mucous discharge, nervousness, increased activity

-stand immobile when pressure applied to rump

Silent estrus is common in swine, _____ can facilitate estrus detection

-presence of boar

What is the first sign of pregnancy in a sow?

failure to return to estrus 18-24d following mating

Pregnant sows spend less time ___, ___, and ___

rooting, walking, and standing

When should you ultrasound a pig to confirm pregnancy? When is the most reliable time to US during pregnancy?

-after 4th week of gestation

-between 30 and 90d

____ can be used from 4 weeks until farrowing and can be used to determine litter size and fetal viability

doppler ultrasonography

Progesterone concentrations of _____ on days 17-19 are typical of non pregnant females

<1ng/mL

An elevate progesterone level on day ____ after breeding is indicative of pregnancy

18

_____ assays are more accurate than progesterone assays.

esterone sulfate

Esterone sulfate is produced by the ____ and reaches peak blood levels at ___d of gestation

-fetus

-23-30d

What kind of placenta does pigs have?

diffuse epitheliochorial

What is the difference between epitheliochorial, endotheliochorial, and hemochorial placentas?

Layers between maternal and fetal blood

-Epitheliochorial - endometrial epithelium, connective tissue, and uterine endothelium

-endotheliochorial - uterine endothelium

-hemochorial - no layers

What animals have an epitheliochorial, endotheliochorial, and hemochorial placenta?

-epitheliochorial - horses, swine, ruminants

-endotheliochorial - dogs and cats

-hemochorial - humans and rodents

How long is the gestation period in pig?

-Duration: 114-115 days (3m 3w 3d)

-mini breeds a few days shorter

What are signs of impending parturition in the sow?

-swollen/reddened vulva

-milk let down

-restlessness, nesting, frequent urination, defecation, chewing and biting

-immediately prior, sow is recumbent

What is necessary for piglets to acquire immunity?

colostrum w/in 12hr of birth

Why do piglets need colostrum within 12hr of birth?

gut closes at 12-24hr after birth

What should the environmental temperature be for the sow? What should the environmental temperature be for the piglets?

-sow is 68-70F

-piglets is 85-95F

How long does farrowing last? Regular interbirth interval? When is vet assistance needed?

-1 to 8hr

-15m

-30 to 60m

Split suckling may be necessary because piglets form a ____ when suckling

hierarchy

How often should the sow's milk supply be checked to look for dysgalactia?

daily

What dose of iron supplement can be given to newborn piglets? How much iron is needed for each kg of growth?

-100-200mg of Fe dextran IM w/in 48hrs

-21mg

What should day 1 care of piglets include?

-disinfect naval

-clip canine teeth

-iron supplement

-ID

-wiegh

-clinical exam

Piglets aged 3-4wk need ___ temp.

Piglets aged 4-8wk need ___ temp.

-85-90F

-75-80F

When are piglets weaned?

3-5wk

Sow savaging can sometimes be observed in sows. What should you do with the sow if this is seen?

-remove the sow and cull from breeding herd

Pigs have highly developed sense of ___ and poor ____

smell, eyesight

Pigs have an innate need to ____

root

Pigs have a large population of "null cells" meaning they lack expression of __, __, and __. They do express ____ making them ___ cells.

-CD2, CD4, and CD8

-CD3

-T

Pig T cells are mostly comprised of ____ Τ cells, found in large numbers in various tissues, especially mucosal sites (such as the uterus) and in newborn piglets

γδ