Reproduction Flashcards
In a case of uterine prolapse, what is the most important thing to tell the farmer while they wait for you to arrive?
Restrict movement.
Do you remove the placenta when repairing a uterine prolapse?
If it comes out easily, then yes. But if you have any difficulty just leave it.
Is replacement of the uterus easier if the cow is standing or recumbent?
Standing, but don’t force them to if they are already down.
Do you give oxytocin before or after replacement of the uterus?
Give after replacement. DO NOT give before or it will go hard and be even more difficult to replace.
What can you do to prevent the uterus from reprolapse in the first few days after treatment?
Use a Bruhner’s stitch.
What can predispose to uterine prolapse?
Hypocalcaemia and dystocia.
When would you consider uterine amputation?
Only if extensive trauma has occurred or if there is uncontrollable haemorrhage.
What must you differentiate when assessing a bladder prolapse?
Whether it is a prolapse or an eversion.
What is important to consider when giving systemic antibiotics for uterine infection?
Whether the minimum inhibitory concentration will be reached within the uterus Is it effective against the known pathogens Residues
What is important to consider when using an intrauterine antibiotic treatment?
Will it be inactivated by debris / anaerobic environment Will it interfere with the uterine defence mechanisms Is it effective against the known pathogens Residues
What is PGF2a useful for in cases of uterine infection?
In cases of pyometra, PGF2a is useful to facilitate uterine drainage by relaxation of the cervix
What is the biggest risk factor for metritis?
Retained foetal membranes
What is the milk withholding period for metricure?
No milk withhold
After how long is a placenta classified as retained?
>12hrs
How long might retained foetal membranes delay uterine involution?
Up to 50 days
Describe the process of normal uterine involution:
Cotyledon proteolysis (by day 3) Caruncle necrosis (by day 7) By day 26-30 the surface of the endometrium covered by epithelium
How long should it take a normal placenta to come away after calving?
3-6hrs
What hormonal therapy would you use for treatment of retained foetal membrane?
None - it is not effective.
What is the risk of reoccurrence for vaginal prolapse v uterine prolapse?
Vaginal prolapse: high risk of reoccurrence. Uterine prolapse: low risk of reoccurrence.
Which cow is most likely in heat?
The cow standing to be mounted.
What is a definitive behavioural sign of oestrus in a cow?
Standing still while being mounted by another cow
What are secondary signs of oestrus in the cow?
- Attempting to mount other cows
- Mounting without standing
- Vulval mucus discharge (clear, thin mucus)
- Vulval swelling (not always apparent)
- Restlessness, (heads held high in dairy yard prior to milking)
- Sexually active groups: groups of cows engaging in mounting activity
- Sniffing
- Licking
- Rubbing
- Aggressive behaviour, Butting, Lip curling (Flehmen reaction), Bellowing
- Chin resting
- Increased ambulatory activity (detected with pedometers)
- Poor milk let down
- Rubbed pin bones or base of tail
During oestrus, what will the concentrations of progesterone, oestradiol, LH and FSH be?
Progesterone: Low (<1 ng/mL)
Oestradiol: High
LH: Increase in frequency and amplitude to LH surge
FSH: increase with LH surge
What factors may decrease oestrus behaviour?
Environment (barn housing, slippery flooring, weather extremes), stress, lameness, poor health, negative energy balance, old age, breed (bos indicus), synchronisation method (GnRH especially)
What is a ‘silent heat’ and when is it especially common?
When a cow is in oestrus but does not stand to mount. Common with the first ovulation post-partum.
How can you improve the efficiency and positive predictive value of heat detection?
Improve cow identification and record keeping, spend time observing cow behaviour, place suspicious cows in with a group of oestrus cows, use heat detection aids, optimise nutrition and health, staff training, consider oestrus synchronisation where there is a significant problem.
What type of aids can be used to help detect oestrus?
Tail paint/crayons, rump mounted devices, pedometers, detector animals, vaginal mucous electrical resistance measurement
What is the expected submission rate over a 3 week period?
High (>85%)
How would you assess submission rates in a year-round calving herd?
At least every 2 months you should calculate the herd’s 80 day submission rate (target 73%)
Ideally, what do we need to do to achieve a precise pattern of onset of oestrus and ovulation and achieve normal fertility?
Synchronise ovarian follicular development.
Synchronise a decline in circulating concentrations of progesterone.
Synchronise a preovulatory LH surge/ovulatory stimulus.
Ovulate follicles at an optimum stage of maturity.
CL following ovulation secretes adequate concentrations of progesterone.
What are the advantages and disadvantages of using a PG program to synchronise oestrus?
Advantages: Easy to administer, variety of programs, normal fertility & economical.
Disadvantages: only animals with CL >5d will respond, ineffective in anoestrus, can cause abortion in pregnant cows, wide pattern of onset of oestrus, dangers to humans.
Describe the physiological reasons for each of the pharmacological treatments that are shown:
GnRH: synchronisation of new wave emergence (will induce ovulation or leutenisation)
Intravaginal progesterone releasing insert: stops ovulation until removal (acts as artificial CL)
Cloprostenol: luteolysis (if a real CL is present)
2nd GnRH: induce ovulation
When would you recommend using EcG to attempt to improve fertility?
In an animal with poor body condition.
What is the general name given to this synchronisation treatment?
Ov-Synch
What is the general name given to this synchronisation treatment?
Co-Synch
What is the general name given to this synchronisation treatment?
Select-synch
What are the advantages of using artificial insemination?
Genetic progress and increased production, disease control, wider choice of sires, safety, improved record keeping
What are the disadvantages of using artificial insemination?
Cost, requires good management, requires skill, inappropriate selection can increase the frequency of undesirable traits, can reduce reproductive performance
List 5 diseases that could potentially be transmitted in bovine semen:
- Tuberculosis
- Brucellosis
- Johne’s Disease
- Trichomoniasis
- Bovine Virus Diarrhoea
List some factors affecting pregnancy rates to AI:
- Dose of semen
- Sire
- Timing of AI in relation to onset of oestrus
- Semen storage
- Semen handling
- Insemination technique
- Poor records
- Fertility of cows
What do the arrows indicate in this image of a cow’s vagina?
Cysts / Garter’s ducts: remnants of the mesonephric ducts in the ovary
In which cows should you not use oestradiol benzoate?
Lactating dairy cows
List some bacterial causes of bovine abortion:
- Brucella abortus
- Leptospira interrogans
- Listeria monocytogenes
- Campylobacter fetus subsp venerealis/Trichomonas foetus
- Escherichia coli
- Mycoplasma
List some viral causes of bovine abortion:
• Bovine viral diarrhoea virus
• Bovine herpresvirus-1 (infectious bovine
rhinotracheitis virus)
• Bluetounge virus
• Akabane virus
List some mycotic causes of bovine abortion:
- Aspergillus
- Mortierella
- Mucor
- Rhizopus
- Candida
- Absidia
List some protozoal causes of bovine abortion:
- Neospora caninum
- Sarcocystis
- Toxoplasmosis
- Theileria sp
What are some of the potential risks for using custom collected semen compared to semen processed within a licensed breeding centre?
No guarantee of quality or disease status
Outline the general steps that are undertaken when processing and freezing bovine semen:
Semen collection -> semen evaluation -> extended (glycerol free) -> cool slowly to 4 degrees -> Add glycerol extender and leave for 4h -> package into straws -> freeze
What is the optimum time for insemination of cows following the onset of oestrus?
4 - 14hrs after the onset of oestrus
Outline the recommended thawing technique for bovine semen:
A sheltered, clean, dry, warm environment away from direct sunlight.
Water bath at 32-38 degrees for 30-60s.
The interval between removing the straw from the nitrogen and AI should be less than 15 minutes.
