Ruminants Anatomy - 2

Objectives

• Reproductive anatomy and Mammary Physiology– Chapter 3

• GI anatomy– Personal notes

The Importance of Reproduction

• Deliver live neonates– Breeding estrous cycle

determinations, reproductive exam, AI, embryo transfer, live cover • Genetics,

– Gestation– Delivery

• Economics

Selection

• Estimated progeny differences– Uses: in males– EPD values: birth, growth, maternal,

and carcass traits and are reported in the same units of measurement as the trait (normally pounds)

– Accuracy: only in same breed. 1 is good and more accurate with more progeny data

Selection

• Estimated breeding values– Uses: value of breeding– Differences between EPDs and EBVs

• EBV also adds potential for heritability• Pedigrees: more in equine

– Breeding systems: inbreeding, linebreeding, crossbreeding (angus+hereford = black brockle face), purebreeding (same breed), outcrossing (different families, same breed) and grading up (grade animal: no documentation of lineage + pure breed)

• Conformation: good udder and footing, not cryptochidism

Reproductive Physiology: Table 3-2

Estrous

• Proestrus– Declining progesterone– Gonadotropin releasing

hormone (GnRH) and follicle-stimulating hormone (FSH)

– Increasing estrogen– Follicular growth

• Estrus – Peak estrogen – Luteinizing hormone– Ovulation

• Metaestrus– Estrogen decreases– Progesterone

increases• Diestrus

– Progesterone is high – Prostaglandin

released if conception does not occur

– Destruction of the corpus luteum

Breeding Soundness Examination

• Purpose: assess fertility• Examination: before breeding season

– Preparation: Safety (chute)– Penis and prepuce

• Tranquilize to relax retractor penis muscle

– Scrotum and testicles– Measurement of scrotal circumference– Breeding behavior – Semen analysis

NB: permanent damage if out more than 2 hours: penile paralysis,Phimosis (swelling prepuce), paraphimosis (swelling prepuce/penis),Priaphism: blood cannot exit glans penis: swelling penis/penis

Prolonged penile extension: phenothiazine based tranquilizers:e.g. acepromazine, chlorpromazine, and promazine

Fibropapilloma: warts

Bull Age (months) Size (cm)

12 - 14 30 - 34

15 - 20 31 - 36

21 - 30 32 - 38

> = 31 34 - 39

Semen Collection and Preparation

• Collection– Electroejaculation – Artificial vagina – Natural stimulation

• Preparation

Optimum temp

Semen Analysis

• Shake container• Keep warm: 37 C/

98.6 F)• Protect from UV

light: warm water bath

• Use gel free fraction of ejaculate

• Extenders: protein, Sugars, antibiotics• cryopreserve

Parameter Normal Values

Ejaculate volume 5 ml (range 1-15 ml)

Sperm concentration1200 million/ml (range 300-2500 million/ml)

Total sperm per ejaculate

Typically 4-5 billion

Progressive motility Greater than 30%

MorphologyGreater than 70%

normal

Semen samples from a bull (left) and dog (right), showing differences in opacity and concentration

Ova viability

24 - 32 h

Onset of Estrus Ovulation

Sperm Viability

12 to 30 h

8 to 12 hsperm transport

6 h

Insemination TimelineInsemination Timeline

Estrous Cycle Determination

• Rectal palpation • Vaginal

examinations – Not useful in cattle

• Ultrasound via rectum– Better for horses

• Observation of standing heat

• Vaginal cytology

Ovaries: Rectal palpation

Estrus: large soft follicles, relaxed hyperemic cervix

KaMar/ Bovine BeaconKaMar/ Bovine Beacon

Tail PaintTail Paint

Tail PaintTail Paint

Other signs: swollen vulva, vaginal discharge, increased vocalization, frequent urination, restlessness

1. Transmitter with pressuresensitive button on top

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2. Mounted onto cow’s rumpusing a patch and adhesive

3. The receiver accepts the mounting activity signal from the transmitter

Receiver

4. Information is transferred tocomputer for processing by

HeatWatch software.

~1/2 mile range

Heat WatchHeat Watch

• Ovsynch uses two hormones

– PGF2α and GnRH

• Ovsynch occurs in three stages– Day 0 - Stage 1: GnRH injection to create a new

follicle

– Day 7 - Stage 2: PGF2α injection to end the current estrus cycle and regress the corpus luteum

– Day 9 – Stage 3: Second GnRH injection to cause the new follicle to ovulate and release the egg • All cows will ovulate 24-32 hours after the

second GnRH injection – Day 10 – Insemination

Estrus Synchronization

• Lutalyse is a veterinary pharmaceutical brand name

• Lutalyse is a PGF2α therapy treatment

• If an animal is known to be open (i.e. her ovulated egg was not inseminated), a shot of Lutalyse will end the cycle and start a new one.

• Lutalyse/ PGF2α will cause the death of the corpus luteum, resulting in reduced progesterone production.

• Pregnant women SHOULD NOT administer shots of Lutalyse; it can cause their bodies to terminate the pregnancy!

Lutalyse

• CIDRs (Controlled Internal Drug Release)– intravaginal progesterone – beef cattle, dairy cattle, goat and

sheep industries. – released at a controlled rate – beneficial in large herds

Estrus Synchronization

Breeding

• Live cover• Prepare perineum/ vulva: cleanse with

povidone iodine– Artificial insemination– Embryo transfer: pathogen free embryos

AI pipette

Breeding (cont’d)

Breeding (cont’d)

• Embryo transfer– Superovulation

• Ovulate multiple eggs

– Breeding: AI or natural– Embryo recovery

• Phosphate buffered saline

– Embryo ID– Embryo transfer: recipient

Pregnancy Detection• Failure to return to estrus• Rectal palpation

– 25 – 30 days

• Ultrasound per rectum– 12 days

• Trans abdominal ultrasound– 95% accurate: 60 days

• Doppler ultrasound– Week 6-7– Fetal heart rate

• External palpation– Ballottement– 7 months

• Abdominal radiographs: not common

• Laboratory tests: estrogen assays: blood, urine, milk

Rectal Pregnancy

• Easiest, fastest, cheapest – status 25 - 30 days post breeding

– US: 12 days (18 days in small ruminants)

– Radiograph: 90 days• Positive signs of pregnancy

– Fetus– cotyledons/caruncles– amniotic vesicle– fetal membrane slip

• Suggestive signs– Ipsilateral corpus luteum– Ipsilateral middle uterine

artery in the broad ligament

US: 40 day pregnancy

Fetal Membrane Slip (be gentle, as you can damage a pregnancy by rough palpation)

32 days thread 1 horn45 small string 1horn60 string 2 horns>70 large string

Pregnancy - Cotyledonary

• Placentomes– cotyledon/caruncle unit)– You must rule out that you a

not palpating an ovary by feeling at least 3.

75 days pea size100 dime115 nickel125 quarter150 half dollar> 150 variable

The fetus descends out of reach from 3-7 months.You can first feel the fetus at 55-60 daysTo estimate an aborted fetus they are:2 months mouse3 months rat4 months small cat5 months large cat6 months beagle dog

• Gestation: Avg. 283 days• 1 – 2 days before

parturition: elevated tail head

• Stage I: Preparatory stage

• ~ 6 hours• Inappetance,

restlessness, kicking belly

• Stage II: Delivery• 30 min – 4 hours

(Avg. 75 minutes)• Heifers take longer• Head diving posture

• Stage III• Expel placenta• 4 – 12 hours• PE calf

Dystocia

• Fetal or maternal: emergency– Fetal more common

• Malformation – “fetal monsters”• Stillbirths• Large fetal size• Fetal malposition

– Maternal• Compromised pelvis: fracture/ old injury• Uterine torsion• Rupture of supporting structures

Dystocia

• 3 approaches: LUBE!!!– Mutation and traction

• Obstetrical chains, calf jacks

– Fetotomy: in cattle– C – section

• Fetus too large, small pelvis, cervix does not dilate, vaginal prolapse, dead fetus, malformed fetus

Dystocia

Dystocia

• C – section– Large fetus– No vaginal

manipulations– Failure of cervix to

dilate– Vaginal prolapse– Fetal emphysema– Fetal monster

Separate Mammary Glands-Quarters

60% 40%

Front quarter is smaller

REAR

Fig 29-3. An illustrated view of the ligaments that permit udder suspension (Courtesy of Iowa State University)

Mammary Gland Structure

• Udder: 4 separate glands– A teat hangs from

each quarter• sphincter muscle

known as streak canal

– extra nonfunctional teats• supernumerary

teats• Removed in calf

Internal Anatomy

• Streak canal– bacteria out

• Teat cistern– Duct in teat : 30-45 milliliters– Separated from streak canal: Furstenberg’s rosettes

• Gland cistern– Separated from teat cistern by the cricoid fold– 400 ml of milk

• Collecting area for the mammary ducts

Fig 29-4. A dissected mammary gland showing the gland cistern, teat cistern and streak canal (Courtesy of Mark Kirkpatrick)

Fig 29-6. Blood flow to and from the mammary gland determines milk producing capability of the cow (Courtesy of Iowa State University)

1 gallon of milk: 400 gallon of blood

• pudic arteries• external pudic veins

and subcutaneous abdominal veins

Digestive System

• Cranial fermentors– Forestomach– E.g. cattle, sheep and deer – digest and extract energy from

cellulose– utilize the protein from fermentative

microbes

• Caudal fermentors• Cecal digestors • E.g. horses and rabbits• digest and extract energy from cellulose • utilize dietary hexose sources directly

Digestive system calf

• Esophageal groove– By pass

reticulum and rumen and goes directly into abomasum

– Grain and forage for rumen development ~ 3 weeks age

Fermentation Ecology• Rumen inoculation

– 1 ml of rumen content: ~10 to 50 billion bacteria,1 million protozoa, variable numbers of yeasts and fungi

– Cellulolytic (digest cellulose)

– Hemicellulolytic (digest hemicellulose)

– Amylolytic (digest starch) – Proteolytic (digest

proteins) – Sugar utilizing (utilize

monosaccharides and disaccharides)

– Acid utilizing (utilize such substrates as lactic, succinic and malic acids)

– Ammonia producers – Vitamin synthesizers:

vitamin B and K– Methane producers

Poor nonprotein nitrogen such as urea to produce VFA, AA, Vit B and K, methane, CO2

Fermentation Ecology

• Rumen pH between 6 and 7 (6.2 – 7.2): Transfaunation

• Grain engorgement: pH <5.5– protozoal populations decrease

• Products: Sugars -> VFA’s– acetic, propionic and butyric acids

Volatile Fatty Acids

• Acetic acid – generate ATP

• Proprionic acid – major substrate

for gluconeogenesis

• Butyric acid, – for energy

production.

Ruminant Anatomy

• the rumen or paunch• reticulum or

"honeycomb," • the omasum or

“book," • the abomasum or

"true stomach." • Esophagus > rumen -

reticulum > omasum > abomasum

Reticulum – ‘honeycomb’

• against the diaphragm (2.5 gal.)

• rumino-reticulum connected by tissue

• Heavy objects fall– Hardware disease

(traumatic reticuloperitonitis)

• No enzyme secretion• Formation of food

bolus

Rumen – ‘Paunch’• largest • sacculated by

muscular pillars: dorsal, ventral, caudodorsal and caudoventral sacs

• stratified squamous epithelium (Papillae lining)

• fermentation vat (25-42.5 gallons, anaerobic bacteria)

• Absorbs most VFA• Healthy cows: 1-2

minutes/contractions

Omasum - book

• broad longitudinal folds or leaves

• Absorption of water (4 gal.)

• Reduce particle size, ingesta between the leaves will be drier than in other compartments

Abomasum – true stomach

– True stomach with a glandular lining (5 gal.)

– HCL and digestive enzymes (proteolytic enzymens: mucin, pepsinogen, renin, lipase), needed for the breakdown of feeds, are secreted into the abomasum

– PH decreases from 6 > 2.5• Denatures proteins• Kills bacteria and

pathogens• Dissolves minerals

H2O vital: Drink 10-14 gal./dy; Dairy cattle at peak lactation: 45 gal. H2O/day (3-5 gal/ lb milk)

Digestive system - Ruminants• The small intestine

– measures about 20 times the length of the animal– duodenum, jejunum, and ileum. – Secretions: pancreas and the gallbladder, which aid

digestion– Most of the digestive process is completed here

• Cecum– SI and LI, where some previously undigested fiber

may be broken down – Function of cecum?

• Large intestine– last segment of the tract through which undigested

feedstuffs pass – absorption of water is the primary – Some bacterial digestion of undigested feed occurs

Function of digestive tract

• Eructation (belching)– Large quantities of gas, mostly carbon

dioxide and methane, are produced in the rumen

• Rumination (4 phases)– 35 to 40 percent of each day ruminating

(cud chewing)– During rest periods, feed boluses (cud) are

regurgitated for rechewing to reduce particle size and for resalivation.

– Feed is more readily digested by rumen microbes as particle size is reduced

– Redeglutition: swallowing

Four Steps of Rumination

• Regurgitation– Reverse peristalsis carries food to

mouth• Remastication

– Liquid squeezed from bolus and swallowed

– Bolus chewed• Reinsalivation

– Adding more saliva• Redeglutition

– Swallowing bolus and liquids

Remastication and Redeglutition

Digestive system - Ruminants

• Motility of the rumen and reticulum– contractions mix Saliva production – 50 to 80 quarts of saliva – provides liquid for the microbial

population, recirculates nitrogen and minerals, and buffers the rumen

– buffer for helping to maintain a rumen pH between 6.2 and 6.8 for optimum digestion of forages and feedstuffs

• Vomiting– Rare: suspect toxins

References

• K Holtgrew-Bohling , Large Animal Clinical Procedures for Veterinary Technicians, 2nd Edition, Mosby, 2012

• Slides courtesy of Dr. H.D. Tyler, Iowa State University

• References: Dr. M. A. Barnes, Virginia Tech and Dairy Cattle Science. 4th Ed. 2005.

• http://www.vet.k-state.edu/studentorgs/bovine/pdf/Reproductive_Physiology.pdf

• http://cal.vet.upenn.edu/projects/repropath/FNormal/ovaries/template.htm

References• Large Animal Clinical Procedures, Elizabeth Hanie.

2006• http://www.fsis.usda.gov/ofo/tsc/

bse_information.htm• http://www.fao.org/docrep/t0690e/t0690e05.htm• http://www.infovets.com/books/smrm/C/C015.htm• http://www.vivo.colostate.edu/hbooks/pathphys/

digestion/herbivores/index.html• http://www.extension.umn.edu/distribution/

livestocksystems/components/di0469-02.html• faculty.fortlewis.edu/LASHELL_B/Nutr2-Rumdigestion.pdf

• http://www.das.psu.edu/research-extension/dairy/nutrition/calves/rumen

• http://www.pitt.edu/~super1/lecture/lec30761/006.htm

References

• http://www.vivo.colostate.edu/hbooks/pathphys/reprod/semeneval/collection.html

• Author: Dr. Dipa Brahmbhatt