ruminants anatomy - 2. objectives reproductive anatomy and mammary physiology –chapter 3 gi...
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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
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
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
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)
• 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
• C – section– Large fetus– No vaginal
manipulations– Failure of cervix to
dilate– Vaginal prolapse– Fetal emphysema– Fetal monster
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
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
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
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