Exam 2 (Cows) Flashcards
Gestation length in Cows
273-292d
Hormone Changes in Prep for Parturition in Cows
o Relaxin and estrogens cause relaxation of pelvic ligaments -> sinking of the tail head
o Relaxin & PGE cause Cervical softening/ripening
o Vulvar edema
o Prolactin, estrogens, glucocorticoids cause udder edema
Pathway that Starts Parturition in Cows
o Increase fetal cortisol ->
o Release PGF2alpha ->
o Luteolysis & relaxin causing pelvic ligament stress
ALSO
o Increase fetal cortisol ->
o Placental P4 ->
o E2 ->
o Lubrication of tract & myometrial contractions –>
o Increased pressure ->
o Cervical stimulation ->
o Oxytocin
Stage I of Labor in Cows; Duration, Clinical Signs, What is happening, Reasons to Intervene
o 2-6 hours(up to 8)
Clinical signs
Isolation from the herd
Discomfort
Kicking at the belly
Restlessness (heifers)
What happens?
Uterine contraction
Cervical dilation
Rupture of the chorioallantoic membrane
“Ferguson reflex”
Abdominal contractions
Reasons to Intervene
No progression to stage 2 after 4 hrs
Severe discomfort
Vaginal bleeding
Excessive straining, rectal prolapse, rectal bleeding
Downer
Stage II of Labor in Cows; Duration, What is happening, Reasons to Intervene
o 0.5-2 hours for cows
o 2-4 hours for heifers
o Cervix is fully dilated
o Appearance of the amniotic sac
o Many lie down
o contractions will increase and abdominal contractions are obvious.
o This stage ends with delivery of the calf
Reasons to Intervene
If amniotic sac is seen or ruptured + the following
No progression/no efforts for 2 hours
Too much effort for 30 minutes and no progression
Expulsive efforts halted for more than 20 minutes
Signs of distress or fatigue
rectal or vaginal bleeding
Severe vulvar swelling
Calf with swollen tongue, meconium staining
Stage III of Labor in Cows
o Uterine contractions
o Variation in blood pressure within the placentome
o Collagenase and Neutrophils activity
o The placenta should be delivered within 6 hours
o Retained placenta if 12 hours or more
Induction of Parturition in Cows; Indications, Prerequisites, Complications, Drugs
Indications
Convenience / management (Not common in the US)
Valuable offspring
Embryo transfer (in vitro fertilization, cloning)
Accident or debilitating disease in the dam
Prolonged pregnancy (fetus gains 0.45 to 0.68 kg/days in final weeks)
Prerequisites
Known breeding date
Need to know if fetus alive or dead
Complications
Retained fetal membranes
Drugs
Dexmethasone + PGF2-alpha
Takes 25-42hrs
Maternal Causes of Dystocia in Cows
o Beef > dairy
o Inbreeding
o Muscular hypertrophy
o Uterine torsion
o Primary uterine inertia due to Hypocalcemia etc
o Secondary uterine inertia due to Exhaustion of the myometrium
o Feto-maternal disproportion (small heifers)
o Abnormalities of the birth canal
o Overconditioning
o Long gestation
o Multiparous
o Hypoclacemia
o ketosis
Fetal Causes of Dystocia in Cows
o Malpositioning
o Monsters
o Oversized
o Twinning
o Male > female
o In vitro produced
Preventing Dystocia in Cows
o Monitor heifer growth
o Select size bulls
o Manage nutrition
o Select for pelvimetry
Rectal Exam for Dystocia in Cows; When? Objectives
Must be performed in all animals if the following
Straining and nothing is showing at the vulva
Only a foot is showing
Bloody discharge
Primary objectives
Rule in/out uterine torsion
Verify pregnancy status and stage
Check for abnormalities of the pelvis
Prep for Vaginal Exam During Dystocia in Cow
o Clean the vulva and perineal area and any protruding fetal parts with surgical soap and water
o Scrub hands and arms
o Use ample lubrication
Caudal epidural
1st intercoccygeal space desensitizes sacral nerves 3 - 5
Sacrococcygeal desensitize sacral nerves 2 – 5 but often calcified in older cows
2% lidocaine 1mL/100kg BW (no more than 5 mL)
Desensitizes tail, vagina, vulva, perineum
High dose: ataxia
What to Examine During Vaginal Exam During Dystocia in Cow
Examine birth canal for any lesions
Evaluate dilation and integrity of the vulva, vestibulo-vaginal sphincter and vagina
Evaluate cervical dilation
Do not rupture the amniotic sac if the cervix is not fully dilated
Determine fetal disposition (Presentation, Position and Posture)
Determine fetal viability
Options for Resolution of Dystocia in Cows
o Vaginal delivery after mutation
o Forced fetal extraction
o Fetotomy
o Cesarean section
o Pelvic symphysiotomy (not recommended)
o Euthanasia
Uterine Torsion in Cow; Diagnosis, Clinical Signs, Treatment
Diagnosis
Most torsion are to the left (counterclockwise)
Broad ligament displacement per rectum palpation
Spiral folds per vagina palpation
Clinical Signs
Tachypnea/tachycardia
Bleeding from rectum
Failure to progress
Raised tailhead
Restlessness
Straining
Anorexia
Death from hemorrhage
Treatment
Lay cow on side of torsion, stabilize fetus, & flip to other side (need 3-4 times)
C-section
Detorsion rod if cervix open & fetus accessible
Repulsion of a Cow Fetus
o “Pushing” the fetus away from the pelvis to make room for manipulations
Requirements
Relax uterus w/ Clenbuterol or Epinephrine
Caudal epidural
Lubrication (pump water soluble lubricant)
Can be done manually or use of the Kuhn’s crutch
Rotation of Cow Fetus
o Turning the fetus on its longitudinal axis
o Partial to take advantage of the largest diameter of the pelvis
o Complete to bring fetus from dorsoilial or dorsopubic to dorsosacral
o Can be done manually using the fetal limbs
o Can use a detorsion rod
Version of Cow Fetus
o Applied in transverse presentation
o Usually not possible in ventral transverse
When is Vaginal Delivery Possible w/ anterior/dorsosacral presentation of calf and posterior/lumbosacral presentation of calf?
Anterior or dorsosacral presentation
* If 1 person can pull fetlocks 10-15cm beyond vulva
* If point of shoulders at level of ilial shafts
Posterior or lumbosacral presentation
* If hock can be exteriorized
* Must rotate fetus 45-90 degrees
When is Vaginal Delivery Impossible During Cow Dystocia?
The head has not moved spontaneously into the pelvis
Fetus is positioned in the birth canal and the forelimbs are crossed
Hooves are rotated with solar surfaces facing medially (i.e. elbows are forced together)
Fetus is lodged and does not move when abdominal press occurs
Extraction of Cow Fetus
o Loop chain above fetlock & Half hitch around pastern
o Maximum 2 / 3 persons (600-800 lpi) or One person per leg
o one foot at the time
o Pull in arc direction
Fetotomy Indications & Requirements
Indications
Dead fetus
Traction is impossible
Cesarean not an option
Requirements
Fully dilated vulva, vagina and Cervix
Experience
Proper equipment
C-Section in a Cow; Indications
Elective / scheduled
Irreducible fetal maldispositions
Pelvic injury or abnormalities of the dam
Uterine torsion
Abnormal vagina: trauma, laceration, severe edema
Salvage of term live fetus
Should never be considered as last resort!
C-Section in a Cow; Surgical Approaches
Standing
* Left paralumbar
* Right paralumbar
Dorsal recumbency
* Right & Left ventral abdominal paramedian
* Ventral abdominal median
Lateral recumbency
* Right or left supramammary (oblique)
* Right or left ventral abdominal paramedian
* Ventral right or left paralumbar
L Flank Laparotomy C-section in Cows; Basics, Sedation, Anesthesia
NOT recommended for cows that are likely to go down or extremely fractious
Sedation
* Ketamine 0.04mg/kgIM
* Butorphanol 0.01mg/kgIM
* Xylazine 0.02mg/kgIM
Anesthesia
* Caudal epidural (Lidocaine/Xylazine) w/ inverted “L” paralumbar block
* Sedation/analgesia (Xylazine/butorphanol)
C-Section in a Cow; Skin Incision, Basics, Approaches, Common Errors
Caudal third of the fossa to facilitate exteriorization of the uterus
35 to 40 cm long
Vertical
* Mid-paralumbar extending ventrally
* Size depends on size of the fetus
Slightly oblique
* 10 cm cranial and 8 to 10 cm ventral to the cranial aspect of the tuber coxae
* Extend cranioventrally at 45° angle ending 3 cm caudal to the last rib
Common errors
* Too high
* Too low
* Too small
* Jagged
C-Section in a Cow; Muscles to cut, Gridding Technique & Common Problems
Incise through the subcutaneous tissues & Internal and external abdominal oblique muscles
Tent the transversus abdominus muscle with forceps and incise with scissors
Use finger to check for any adhesions and direct incision with scissors
Modified gridding technique
* Limits the size of the incision
* Difficult exteriorization of the uterus
Common problems
* Excessive bleeding (insure hemostasis)
* Pain: Cutting through nerve branches
* Inability to identify the peritoneum
* Incision through to the rumen
C-Section in a Cow; Exploration of the Peritoneal Cavity
Use sterile wet sleeves
Determine the location, size and position of the fetus
Check for any uterine/cervical lacerations
Check for uterine torsion
Check tone/relaxation of the uterus
C-Section in a Cow; Exteriorization of the Uterus, How to & Common Problems
Locate the tip of the uterine horn
Grasp the leg of the fetus within the tip of the uterine horn
Bring the tip of the horn into the abdominal incision
Problems
* Very difficult if fetus is large or uterus is contracted (Epinephrine to relax uterus)
* Never grasp the uterine horn without fetal limb!
* Transverse presentations are very difficult
* If you cannot bring the uterus up make blind uterine incision using a sterilized letter opener
C-Section in a Cow; Uterine Incision & Problems
Incision should be made over the greater curvature
Start at the tip of the horn and extend caudally
Stab incision and extended with scissors
Incision should be long enough to accommodate fetal limbs and head (caudal presentation) or the hips (cranial presentation)
Do not hesitate to extend uterine incision during delivery
Problems
* Too small incision resulting in uterine rupture or tears
* Too close to the broad ligament
* Too close to the body and cervix
* Spillage of uterine fluid or lubricant into the abdominal cavity
* Excessive hemorrhage due incision of placentomes
C-Section in a Cow; Delivery of the Fetus in Cranial or Caudal Position
Cranial presentation
* Apply chains to both hind legs
* pull dorsal and lateral until the pelvic area is brought to the abdominal incision
Caudal presentation
* Apply chains to the forelegs
* Locate and align the head with incision then apply traction
* May need to use a head snare
C-Section in a Cow; Uterus Closure, Problems
Exteriorize as much of the uterus as possible
Hold uterus with uterine clamps
Check for lesions or abnormalities
Remove the placenta only if completely detached and comes out easily
Trim cord and placenta and replace in the abdominal cavity
Single layer Utrecht if healthy
double-layer closure Lembert then Utrecht if risk of leakage
Start at the caudal commissure
May administer oxytocin after closure
Check uterus for leakage, clean, and replace in normal position
Use a saline solution of heparin, penicillin K, or tetracycline
Problems
* Edges not inverting properly
* Knots not buried
* Uterine tears at the suture points (weak or damaged uterus)
* Jagged uterine incision
C-Section in a Cow; Abdominal Closure
Abdominal lavage as indicated
Eliminate as much air from the abdomen as possible during suture**
Always start from the ventral commissure
Peritoneum, transverse and internal oblique muscles Simple continuous pattern
External oblique abdominal muscle and subcutaneous tissue in simple continuous pattern
Close skin w/ ford interlocking
C-Section in a Cow; Complications
o Emphysema
o Peritonitis (abdominal lavage)
o Endotoxemia, postoperative sepsis
o Abdominal adhesions
o Retained placenta, metritis
o Surgical site infections
o Reduced fertility
C-Section in a Cow; Umbilical Care
o Maternity pen hygiene
o Reduce calf residency time in calving pens
o Adequate early intake of good quality colostrum
o Immediate and repeated cord dipping with chlorhexidine
o “cloned” calves may need surgical resection of the umbilical stump
Colostrum Quality in Cows
o Mass of IgG available for absorption should be >100 g/L
o Colostrum high in red blood cells may exacerbate any diarrhea caused by gram (-) bacteria
o Routine pasteurization methods reduces IgG concentrations
o Heat treatment at 60°C for 30 min reduces bacterial count, preserves IgG concentration and increases the apparent efficiency of absorption of IgG
Colostrum Absorption in Cows
6hrs after birth
50%
8hrs
33%
After 24hrs
No absorption
Failure of passive transfer
Serum IgG <10mg/mL
If giving calf pasteurized colostrum, need to give all w/in 4hrs of birth
Septic Metritis in Cows; Clinical Signs, Usual Flora, Treatment
Clinical Signs
2-14 days postpartum
Anorexia
Drop in milk production
Pyrexia
Tachycardia
Tachypnea
Dehydration
Large fluid filled uterus
Dark brown to red foul smelling discharge
Diarrhea
Rumen atony
Toxemia
Usual Flora
Trueperella pyogenes
Fusobacterium necrophorum
Bacteroides spp.
E. coli
Treatment
Penicillin, ceftiofur, ampicillin, oxytetracycline
NSAIDs
Fluid therapy
Supportive therapies
Uterine Prolapse in Cows; Predisposing Factors, Treatment
o First 24 hours (maybe longer)
Predisposing factors
Hypocalcaemia
Tenesmus (vaginal injury, prolonged dystocia)
Excessive extraction force
Large fetus
Calving paresis
Treatment
Replacement
Hysterectomy
Slaughter salvage/ euthanasia
Uterine Prolapse in Cows; How to Replacement
Epidural ->
Standing or place in sternal position & extend legs out behind cow to allow uterus to be elevated above the perineum ->
Clean the uterus with warm water and mild antiseptic ->
Massage the uterus to reduce edema (use large wet towels) ->
Replace starting at the cervix ->
Use close fists to continue to push the uterine horns through the cervix ->
Make sure that the uterine horns are extended all the way to avoid necrosis of invaginated tips by filling uterus with large volume of warm water w/ mild antiseptic ->
Administer oxytocin ->
Treat hypocalcaemia if needed ->
Place Buhner suture if cow is weak and not ambulating ->
Systemic antibiotics and NSAIDs as needed ->
If all fails – Uterine amputation
Dairy; Age at first breeding, age at first calving, weight at 1st calving
Breeding
14-15mo
Age at Calving
24mo
Weight at Calving
1200lbs
Annual Repro Cycle in Dairy
o Pregnancy - 280 days
o Waiting Period – 60d
o 3-4 cycles to get cow pregnant again
o Days open - 85-110d
Dairy; Average Days Open
o Number of days from calving to date of insemination resulting in confirmed pregnancy
o 100 –110 days
o most commonly used parameter to evaluate reproductive efficiency
o does not include cows culled for reproductive problem and does not reflect the distribution
o There should be less than 10% of the cows open after 150d
Dairy; Heat Detection Efficiency & Heat Intervals
Heat Detection Efficiency
o % Cows pregnant at the first pregnancy diagnosis
o Should ~ 80-85%
Heat Intervals
o < 18days - error, cystic ovarian condition, PGF2α administration
o 18 to 24 days - normal
o > 24days – missed heats, early embryonic death
Dairy; Breeding Efficiency Indices, calculate preg rate
o Aim for 1.5-2 services per conception
o Heifers 65-70% conception rate
o Lactating cows 30-55% conception rate
o Pregnancy rate = Heat detection rate (HD) x Conception Rate (CR)
Dairy; Who & What to Regularly Examine Post Calving
First 10 days
Cows that had dystocia
Abnormal discharge after calving
Retained placenta
15 to 45 days:
Uterine involution
abnormalities (metritis, pyometra, cysts)
Ovarian activity
Dairy; Pregnancy Diagnosis
First pregnancy diagnosis
28 days by transrectal ultrasonography
28-30 days PSPB
32-35 days by transrectal palpation
First confirmation:
70-80 days of pregnancy
Second confirmation:
at dry off
Freemartinism; Basics, Diagnosis
o 92% of females born co-twin w/ male
o Due to Anti-Müllerian hormone
o Normal or hairy external genitalia
o Short vagina, underdeveloped uterus, hypoplastic ovaries
Diagnosis
Transrectal palpation in adults
Test vaginal depth in claves <30d old
PCR to detect Y antigen
White Heifer Dz
o Recessive sex-linked gene w/ white hair coat
o Segmental aplasia of the paramesonephric ducts & cervix
o Normal ovaries
o Persistent hymen (Shorthorn cattle)
o Mucometra
Postpartum Dzs
o Calving associated injuries and accidents (few hours after calving)
o Retained placenta (few hours)
o Toxic mastitis (1- 3 wks)
o Postpartum metritis and delayed uterine involution (1-few weeks)
o Metabolic diseases (1-60 days)
o Cystic ovarian disease (first 60 days)
o Anestrus
Dairy; Transition Period
o 3 weeks before to 3 weeks after parturition
o Rapid fetal growth
o Colostrogenesis
o Initiation of lactation
o High demand in energy, glucose, amino acids, minerals, and other nutrients
o Negative energy balance
Dairy; Pathophysiology of Dz During Transition Period
Lipid mobilization
Increased serum level of Non-Esterified Fatty Acids (NEFAs)
Increased ketone bodies, Acetone, acetoacetate, and ß-hydroxybutyrate (BHB)
Decreased immunity
Leucopenia
Decreased INFγ and IgM synthesis
Reduced phagocytosis
Increased concentrate in the ration
Ruminal acidosis
Inflammatory cytokines and acute phase proteins
Increased risk for metritis, laminitis, mastitis, displaced abomasum
Dairy; Uterine Involution
o 2 week postpartum: No fluid
o 2-3 weeks: Uterus is retractable
o 3 Weeks: Size reduced by 80%
o 40 days: Complete involution
o Delayed if underlying dz
Retained Placenta; What, Pathogenesis, Treatment
o >12 hours postpartum
o failure of detachment (primary) or failure of expulsion (secondary)
Pathogenesis
decreased collagenolytic activity
due to presence of anticollagenase & reduced collagenase due to hypoclacemia
deficit in neutrophil phagocytic activity
Treatment
NO manual removal or PGF2-alpha
Oxytocin for failure of expulsion
Antibiotics if septic
Injection of collagenase into umbilical arteries
Uterine Infection; Effect on Repro, Diagnosis, Treatment, Prevention, Fever
Effect on Repro
Increase Days open by 15 days
Diagnosis
Palpation
degenerative left shift in septic metritis
Treatment
penicillin/ceftiofur
fluid therapy
NSAID
oxytocin (20 to 40 IU every 2 to 6 hours),
PGF2α (pyometra)
Prevention
Nutrition (body condition, Prepartum ration, DCAD)
Calving management/care
Postpartum (Fresh) cow monitoring program
Temp daily for the first 10 days post-partum
Fever
* ≥ 103°F (Cows)
* ≥ 102.5°F (Heifers)
Dairy; Postpartum (Fresh) Cow Program If cow has fever
Looks Sick
Oxytocin
Flunixin meglumin or aspirin
IV dextrose, oral propylene glycol
Oral calcium or 250 ml Ca Gluconate IV
Penicillin, Ceftiofur (if metritis)
Looks Healthy
Day 1: Same as sick cows (NO ANTIBIOTICS)
Day 2: Same as sick cows, if temperature persists
Day 2: if normal temperature, recheck the following day
Dairy; Postpartum (Fresh) Cow Program If cow does not have fever
Looks Sick
IV dextrose, oral propylene glycol
Glucose promoters (corticosteroids)
Oral calcium or 250 ml Ca Gluconate IV
Check for DA
Add antibiotics if fever develops
Looks Healthy
Continue to monitor temp
Cystic Ovarian Dz; Basic, Causes, Treatment
o > 25 mm for more than 10 days in absence of a corpus luteum
o Results in nymphomania, anestrus, rarely normal cycles
Causes
Adrenal hyperfunction
Postpartum diseases
High production (> 3rd parity)
Genetics
High selenium levels
Treatment
GnRH or hCG
Follow w/ PGF2-alpha
Spontaneous recovery possible
Dairy; Anestrus; False Vs True, Causes
False
Pregnancy
Heat detection problems
True
Small inactive ovaries
Persistent luteal function
Persistent corpus luteum
Pyometra
Causes of ovarian inactivity
Poor growth/parasitism
Trace mineral deficiencies
Negative energy balance (mature cows)
Association w/ Hypocalcemia, ketosis, retained placenta, displaced abomasum
Dairy; Estrus Signs
o Lasts 15-18 hrs
o Allows mounting
o Mucous discharge
o Reddening and swelling of the vulva
o Increased activity
o Chin resting
o Lip curling
o Drop in milk production
Dairy; Herd w/ Inefficient Estrus Detection
o Very few heats observed before service
o Prolonged calving to 1st service interval (should be less than 18 days beyond VWP)
o Interestus interval > 30 d, or multiple of 21
o More than 15% of cows open at the first pregnancy diagnosis
o Cows are cyclic (vet. Examination)
o Less than 50% of eligible cows are observed in estrus
Dairy; Reasons for Poor Conception Rate
Uterine disease (endometritis)
Failure of ovulation
Change in body condition
Heat stress: effects on oocyte quality
Timing of insemination
Semen quality
Semen handling
Insemination technique
Dairy; Effects of Heat Stress on Fertility
o Temp > 26C or 78-79F
o Decrease oocyte & embryo quality
o Increased granulosa cells degeneration
o decreased steroidogenesis
o Decreased progesterone
o Effect can last over several cycles
Dairy; Iatrogenic Causes of Abortion
o PGF2-alpha first 150 days of pregnancy
o Dexamethasone + PGF 2 alpha last trimester
Dairy; Factors that Contribute to Pregnancy loss
Abortion = loss between 42-260 days
o Genetics
o Heifers > 26mo
o Older & multiparous
o Heat stress
o High milk production
o Timing of insemination
o Metabolic dz
o Mastitis
o Lameness
Brucellosis; Transmission, Clinical Signs, DIagnosis, Prevention
Transmission
Oral
venereal
Hematogenous
Mammary gland,
lymph nodes
gravid uterus
Clinical Signs & Lesions
Abortion in 2nd half of pregnancy
Severe placentitis
Autolyzed fetus
Diagnosis
FA
Culture of abomasal fluid, lung, placenta, milk, uterine fluid
Paired serum samples 1:100
Prevention
Test
Vx
Leptospirosis; Clinical Signs, Diagnosis
Clinical Signs
Abortions during last trimester
Abortion following 7-10 day illness
Fever
Anemia
Hemoglobinuria
Icterus
Agalactia
Mastitis
Death
Autolyzed fetus
Diagnosis
Culture of urine, placenta, feces
FAT
Dark field microscopy
Paired serum samples of herd 1:800
Paired serum samples on cow 1:40
PCR on fetal kidney
Listeriosis; Clinical Signs in Cow, Clinical Signs in Fetus, Diagnosis
Clinical Signs in Cow
Abortion in last trimester
Rare fever
Anorexia
Encephalitis
Retained placenta
suppurative placentitis
Necrosis of cotyledon
Clinical Signs in Fetus
Autolysis
Fibrinous pericarditis
Focal liver necrosis
Suppurative hepatitis
Diagnosis
Culture & histo of placenta
IHC of abomasal contents, vaginal discharge, tissues
Mycotic Abortion; Agents, Time of Year, Clinical SIgns, Diagnosis
Agent
Aspergillus
Mucor
Rhizopus
Time
Sporadic abortions
After wet summer w/ moldy hay
Clinical Signs
Placentitis w/ thickened placenta
white erythematous or ringworm like lesions
Diagnosis
Hyphae from placenta or fetus on histo
Neosporosis; Pathogenesis, Clinical Signs, Diagnosis
Pathogenesis
Ingestion of oocysts and development of tachyzoites in placenta and amniotic fluid ->
Vertical transmission to heifers ->
Bradyzoites develop in central nervous system
Clinical Signs
Resorption and mummification of fetus possible
Abortion between 4 and 7 months of pregnancy
Placentitis
Autolyzed fetus w/ no gross lesions
Foci of cellular infiltrate in the brain, Non-suppurative epicarditis, myocarditis, myositis, Portal hepatitis on histo
Diagnosis
IFA of fetal fluid
Parasite ID w/ IHC or PCR
BVD; Different Symptoms at Different Times in Pregnancy
Days 0-42
Infertility or early embryonic death
Days 18-125
persistently infected calves
Abortion
Mummification
Defects after 100 days
Cerebellar hypoplasia
Retina dysplasia
Intrauterine growth retardation
Mandibular bradygnathism
Hydrancephaly
Hypomyelinogenesis
Partial alopecia
Days 125-170
Abortion possible
Fetal abnormalities
Calves born with congenital defects have precolostral serum virus-neutralizing titers to BVDV
Days 170+
No abortion
birth of normal appearing calves with pre-colostral antibodies
BVD; Diagnosis, Control
Diagnosis
Aborted fetus submitted for viral isolation
ID of PI calves w/ IHC, PCR, or ELISA
Control
Vx
Infectious Bovine Rhinotracheitis; Agents, Clinical Signs, Diagnosis, Control
Agents
Bovine Herpes
1.1 & 1.2a cause abortion & resp symptoms
1.2b causes genital lesions
Clinical Signs
Fever
Respiratory signs
Infertility
Infectious Pustular vulvoginitis (IPV)
Infectious balanoposthitis (IBP)
Abortion storms last half of gestation after respiratory problems
Abortion 20-52 days post infection
Focal hepatic necrosis of fetus
Placentitis
Diagnosis
Viral isolation from fetal tissue via FA or IHC
Control
Vx
Types of Fetal Membrane Hydrops
o Cow looks severely bloated
o Hydrallantois
o Hydramnios
Fetal Mummification; Clinical Signs, Treatment
Clinical Signs
Overdue fetus
Found as mass or bony structure on transrectal palpation
Treatment
PGF2-alpha?
Surgical removal
Fetal Maceration; What, Clinical Signs
Death of fetus contaminates uterus and cow fails to expell
Persistent abnormal vaginal discharge
Infertility
Beef Production Efficiency; Definition, Components
o number of pounds/kg of marketable beef produced per year per cow
Components
Pregnancy rates
Calving rates
Weaning rate (calf losses)
Weaning weight
Beef Heifers; Age at first calving, Age at conception, Distribution of calving for heifers, Breeding season Length
Age at first calving
24 months
Age at conception
13-15 months (65% of estimated mature weight)
Distribution of calving for heifers
90% of heifers should conceive in the first cycle
Breeding season
42 days
Beef Cows; Calving Interval, Distribution of calving , Breeding season Length
Caving interval
12 months
Must conceive by 100 days postpartum
Breeding season length
63 days
Distribution of calving for cows
65-70% should conceive in the first cycle
Pregnancy rate: >95%
Pregnancy loss rate <5%
Calving rate >85%
Calf loss <2%
Beef; Winter Vs Spring Vs Fall Calving
Winter
Calves are older at time of sale
Older, bigger breeding bulls for sale
No mud at calving time
risk of cold exposure to neonates
Increased cost of feeding
More problems with postpartum anestrus
Market prices for commercial calves may be low
Spring
Good weather conditions
* Low cost of nutrition
* Early resumption of cyclicity
* Calves sold before winter
* Calving area muddy
* Breeding occurs during the hottest period of the year
* Market prices for commercial calves low
Fall
* Good weather conditions
* Cows calve in excellent body condition
* Early resumption of cyclicity
* Breeding occurs before hot season
* Calves sold at high prices
* Increased feeding cost for cows and claves during winter
* Breeding occurs during the shorter days of the year
* Calf weights may low in early spring
Effects of Repro Tract Scoring on Repro Career in Beef Cows
o Heifers with RTS 1 or 2
o more likely to be in anestrus for first 24 days of breeding season
o Take longer to get pregnant
o Have lower overall pregnancy rate
o Have a shorter productive career
Reasons for Poor Pregnancy Rate & Long Calving Period in Beef Cows
Postpartum anestrus
Effect of suckling (lactation anestrus) -> Low frequency of LH secretion
Need at least 45 to 50 days to resume cyclicity (longer if first calf heifer)
Relationship between BCS at calving and resumption of cyclicity
Loss of BCS in the postpartum period increases length of anestrus
Partial/temporary weaning (48 hours) may help
Nutritional deficiencies
Copper, Selenium, Zinc, Vit.
increased risk for long anestrus and early pregnancy loss
Trichomoniasis; Agent, Pathophysiology, Clinical Signs, Diagnosis, Prevention
Agent
Tritrichomonas foetus
Pathophysiology
Protozoa colonizes the epithelium of the prepuce and penis (mucosal surface)
No symptoms in bulls
Clinical Signs
Cervicitis
Endometritis
Pyometra
Salpingitis
Early pregnancy loss (<3 months) 7 to 9 weeks after infection
Abortion usually < 5 months (less common)
Infection cleared in 6-18wks but transmitted to bulls in meantime
Diagnosis
Culture of preputial scraping, Pyometra fluid, or fetal Abomasal content to ID parasite by PCR or microscopic exam
IHC placenta and fetal tissue
Prevention
Purchase virgin bulls and test all bulls
Vx helps some but not as much as above
Campylobacteriosis; Agent, Pathophysiology, Prevention
Agent
Campylobacter fetus
Pathophysiology
Confined to the epithelial surface of the glans penis, prepuce and urethra
Asymptomatic in bulls (Chronic carrier)
Prevention
VX heifers 2x 3-4wks apart 30d before breeding
Vx bulls 2x (double dose) 4wks apart then booster before breeding
Campylobacteriosis; Clinical Signs in Cows & Fetus, Diagnosis
Clinical Signs in Cows
Endometritis
Salpingitis
Infertility, irregular estrus cycles**
Early embryonic death
Placentitis
Abortion (rarer)
Clinical Signs in Fetus
Bronchopneumonia
Pleuritis, peritonitis
Hepatitis
Diagnosis
Culture and PCR of Placenta, Cervical mucus, Preputial wash in bulls
Clark’s medium important for culture
Pine Needle Abortion; Toxin, Clinical Signs, Diagnosis, Treatment
Toxin
Isocupressic acid
1kg of needles per day for several wks
Clinical Signs
Early pregnancies are not affected
Vulvar edema and mucoid bloody vaginal discharge in mid to late term
Premature delivery, stillbirths, or abortion
Weak uterine contractions
Dystocia
Failure of cervical dilation
Birth of weak calves
Diagnosis
tetrahydroagathic acid in fetal thoracic fluid and stomach content
Treatment
activated charcoal,
Na thiosulfate
Foothill Abortion (Epizootic Bovine Abortion); Etiology, Clinical Signs, Fetal Lesions, Diagnosis, Prevention
Etiology
CA, NV, OR
Tick vector
Clinical Signs
Transplacental intracellular infection between 60 and 140 days
2 to 3 months progression
Fetal Lesions
Not autolyzed
Ascites
excessive fibrin
hepatomegaly & splenomegaly
petechial hemorrhages
skin lesions
enlarged lymph nodes
focal necrotizing lesions
depletion of cortical thymocytes and macrophage infiltration in the thymus
Diagnosis
Fetal lesions
PCR on fetal tissues
Prevention
Reduce exposure of naïve cattle during the breeding season
Expose naïve cattle prior to breeding season (natural immunity last 2 to 3 years)
Vaginal Prolapse; Factors, Treatment, Post-treatment
Factors
Genetics (Hereford or Charolais)
Age / multiple pregnancies
Intra-abdominal pressure in late pregnancy
Excess perivaginal fat
Prior perivaginal injury
Intake of large volumes of poorly digestible roughage
Poor vaginal conformation
Estrogenic influence on relaxation of the perineal area
Incompetence of the constrictor vestibule and vulvar muscles
Hypocalcemia
Treatment
Caudal epidural anesthesia
Disinfection of the tissue and perineal area
Evaluation of the tissue for lesions
Replacement
Buhner technique closure
Post-treatment Care
+/- antimicrobials
anti-inflammatories
Long term epidural
Monitor calving
Vaginal Prolapse; Grade
Grade I
* Intermittent prolapse of the vaginal mucosa when recumbent
Grade II
* Continuous prolapse of the vaginal mucosa with possible entrapment of the urinary bladder
Grade III:
* Protrusion of the entire vagina and cervix with entrapment of the bladder
* may lead to placentitis
Grade IV
* Chronic complete eversion with severe tissue necrosis of the vaginal mucosa
* can become complicated with peritonitis
Arthrogryposis multiplex (curly calf); What is it, Prevention
o Lethal autosomal recessive genetic defect
o Angus breed
o Permanent contracture of the forelimbs and hind limbs
o Abnormal curvature of the spine
o Very small and lack muscle development
o Cleft palate
o Calves are generally stillborn, or die shortly after birth
Prevention
Must test all bulls
Male carriers can’t be registered
Lupine toxicosis (Crooked calf syndrome); Toxin, Pathogenesis, Clinical Signs, Prevention
Toxin
Lupine
Pathogenesis
Ingestion between 40-100d gestation
Desensitation of skeletal muscle nicotinic acethylcholine receptors
Reduced fetal movement
Clinical Signs
Arthrogryposis
Scoliosis
Kyphosis
Cleft palate
Muscle atrophy
Prevention
Management of grazing during the susceptible period
Changing calving season
Breeding Soundness Exam of Bulls
Ranked as satisfactory, deferred, or unsatisfactory
Physical examination
Reproductive evaluation
Scrotal/testicular palpation
Minimum scrotal circumference
transrectal palpation
Semen collection and evaluation
Normal erection and ejaculation
Minimum sperm motility (need 70% normal sperm)
Sperm morphology
Testing for venereal diseases is NOT part of the regular BSE but should be encouraged.
Young bulls & Breeding Soundness
o Disqualified due to poor sperm morphology or small scrotal circumference
o If pass, allowed to breed 15-25 cows (younger breed less)
Persistent Frenulum; Basics & Treatment
o Persistence of the preputial-penile adhesions
o Suspected to be hereditary
o Bulls cannot achieve full erection and exteriorization of the penis
o Treated bulls should be used as terminal sires (should not use to produce males due to hereditary)
Treatment
Snip & suture
Fibropapilloma; Basics, Treatment, Prevention
o “Penile warts”
o Bovine fibropapilloma virus
o Usually, young bulls mounting each other
Treatment
Surgical excision
Easy if small and pediculated
Complicated if large, wide- based
Treated Bulls should be reexamined 30 days later prior to use for breeding for regrowth
Prevention
Autologous vaccine made from removed warts
Preputial Lacerations; How, Grade, Treatment
o Discrepancy in size between cow and bull
o Breeds w/ pendulous prepuce
o Polled breeds (absence of retractor preputial muscle)
Grade
I – preputial prolapse, slight/moderate edema
II – moderate/severe edema, slight necrosis
III – severe edema, deep laceration, moderate necrosis, fibrosis
IV – severe edema, deep lacerations, deep necrosis, fibrosis, and often abscess
Treatment
Medical management (I & maybe II)
Circumcision - Closure of preputial epithelium, preputial skin and placement of penrose tube over the free portion of the penis
Preputial amputation
Penile Hematoma (Broken Penis); Pathogenesis, Diagnosis, Complications
Pathogenesis
Breeding injury
Rupture of the tunica albuginea
Extravasation of blood from the corpus cavernosum penis
Dorsum of the penis on the distal bend of the sigmoid flexure
Diagnosis
site of lesion
ultrasonography
Complications
Preputial prolapse
Adhesions
Abscess
Penile Hematoma (Broken Penis); Treatment
Conservative
* Must be less than 20cm
* Broad spectrum antibiotics
* Hydrotherapy
* Sexual rest for 60d at least
* 60-70% of bulls return to breeding without surgery
Surgery
* Best 5 to 7 days after accident
* Removal of the blood clot and repair of the rent
* Sexual rest: 60-90 days
* 75% of bulls recover and return to breeding if surgery is performed w/in first week
Spiral Deviation of the Penis; When is it normal/abnormal
o Normal inside vagina at time of ejaculation
o Normal during electroejaculation
o ABNORMAL if seen during erection before entering vagina
Vesicular Adenitis (seminal vesiculitis); Basics, Agents, Risk Factors
o Most common accessory sex glands disorders in bulls
o Young > older
o Primarily hematogenous
Agents
Brucella abortus,
Trueperella pyogenes,
Histophilus somni,
IBR,
enterovirus
Risk factors:
Age
high energy ration, acidosis
other infections
Vesicular Adenitis (seminal vesiculitis); Clinical Signs
Acute
* Enlarged gland
* Painful on palpation
* Lameness +/-
* Abdominal pain
Chronic
* Adhesions,
* abscess,
* fistulation tract draining in rectum
Vesicular Adenitis (seminal vesiculitis); Effect on Ejaculate, Treatment
Effect on Ejaculate
Presence of pus or blood
Sedimentation
Presence of neutrophils in semen (1 per 3 high power x1000 fields)
Poor motility due to inflammatory cytokines
Increased detached heads
Treatment
Spontaneous recovery possible in young bulls < 2 years
Older bulls have poor prognosis for recovery
Tulathromycin
Tilmicosin
Cull if > 9year
Look at Bull slides for pictures of Testicular Asymmetry
o Testicular atrophy
o Seminoma
o Inguinal hernia
GnRH & Analogues; What is it, Function, Indications
o Neuropeptide produced in Hypothalamus
Function:
Stimulates FSH and LH release
Indications
Induction of ovulation
Induction of follicular growth
Progesterone; What is it, Function, Indications, Available Forms
o Steroid produced by Corpus luteum
Function
Inhibit LH surge
Maintenance of pregnancy
Indications
Synchronization of follicular waves
Available forms
Progesterone
Megestrol acetate
PGF2-alpha & Analogues; What is it, Indications, Available Forms
o derivative of arachidonic acid producd by Endometrium
Indication
Luteolysis
Available forms
Natural: Dinoprost tromethamine
Synthetic: Cloprostenol
Methods to Improve Heat/Estrus Detection
PGF2α and analogues
1 injection + heat detection and AI
2 injections 11 to 14 days apart: Heat detection and AI
Controlled Internal Drug Releasing Device (CIDR)
Insertion for 7 days ->
1 day prior to removal administer PGF2α ->
heat detection and AI
PGF2α or analogues for bypassing estrus (heat) detection; Method, Physiology
Method
2 injections of PGF2α 11-14 days apart ->
AI at 80 hours or 72 and 96 hours after the second injection
Physiology
Injection of PGF2alpha during luteal phase ->
regression of CL ->
estrus in 2-5d
Ovsynch for bypassing estrus (heat) detection; Methods
Basic Method
Day 0: GnRH – induce ovulation or induce luteinization
Day 7: PGF2α – lyses CL or luteinized follicle
Day 9: GnRH – induce ovulation of mature follicles
AI 8 to 16 hours after second GnRH
Presynch-Ovsynch Method
give PGF2alpha 14 & 10 days prior to day 0
Double Ovsynch Method
GnRH 17 days prior ->
PGF2 14 days prior ->
GnRH 7 days prior to day 0
CIDR + Ovsynch for bypassing estrus (heat) detection; Method
Day 0: CIDR placement + GnRH
Day 7: CIDR removal + PGF2α
Day 9: GnRH
12 hours later: AI
