Bovine Reproduction Flashcards
(134 cards)
1
Q
How many follicular waves does the average cow have in a follicular cycle?
A
2-3
2
Q
What is luteolysis determined by?
A
Prostaglandin receptors
3
Q
What does AI success depend on?
A
Reliable oestrus detection
Use of fertile/proven sires
4
Q
Is it better to inseminate too early or too late?
A
Too early
5
Q
How many sperm are there in a straw?
A
12 million
6
Q
When does endometritis tend to occur?
A
21 days + post-calving
7
Q
When does metritis tend to occur?
A
Up to 21 days post-calving
8
Q
Give some differentials for vulval discharge in a cow
A
Pyelonephritis RFM Endometritis Metritis Cystitis Vaginitis
9
Q
How would you diagnose pyelonephritis in a cow with vulval discharge?
A
Catheterisation of bladder
Palpate kidneys per rectum (will be painful if inflamed)
10
Q
Which antibiotics tend to concentrate in the urine?
Give a condition this could be used for
A
Penicillin (hence useful for pyelonephritis)
11
Q
Why is it worth cleaning a cows tail when investigating vulval discharge?
A
So you can identify any further discharge
If not, can’t tell whether discharge is new or old
12
Q
How can you administer tetracyclines?
A
Liquid suspension (injection) Tablets to be inserted into the uterus (pessaries) (milk withhold of 4 days)
13
Q
Do 1st gen cephalosporins have a milk withhold?
A
No
14
Q
Why may iodine be used in cases of vulvular discharge?
A
Releases prostaglandin from uterus
15
Q
What are the 4 stages in the follicular cycle?
A
Emergence -> selection -> dominance -> atresia
16
Q
What do the umbilical arteries become in calves?
A
Lateral ligaments of bladder
17
Q
What does the umbilical vein become in calves?
A
Round ligament of liver
18
Q
What does the urachus become in calves?
A
Median umbilical ligament
19
Q
Where does the umbilical vein lead to in calves?
A
Liver
20
Q
What should you check when diagnosing umbilical swelling in calves?
A
Suck reflex Joint ill Spread/source of infection Lungs CNS
21
Q
If an umbilical swelling in a calf is reducible into the abdomen what kind of hernia is it?
A
Simple hernia
22
Q
If an umbilical swelling in a calf is partially reducible into the abdomen, what kind of hernia is it?
A
Hernia and abscess
23
Q
If an umbilical swelling in a calf is irreducible into the abdomen what kind of hernia is it?
A
Abscess
Hernia complicated by incarceration/strangulation/adhesions
24
Q
What would a pitting oedema signify in a calf with an umbilical hernia?
A
Urolithiasis (bladder stones) and urethral rupture
25
How can you identify discharging tracts in a calf with umbilical hernia?
Pass a blunt probe (eg bitch urinary catheter) to see which direction it goes/how far etc
Inject radio-opaque contrast medium and take radiographs with US
26
What is fibrinogen an indicator of?
Chronic inflammation
27
What is the usual cause of simple hernias in calves?
Genetic
28
How big must a simple umbilical hernia be for you to perform surgery?
Larger than one finger diameter
29
How should a calf be treated after umbilical hernia surgery?
Must have minimum 1 month box rest and not be turned out for 3 months after surgery to avoid wound breakdown
Add calf to a group of smaller animals to prevent bullying
30
What sedative should you use when performing surgery on a calf with a simple umbilical hernia?
Xylazine
31
What local anaesthetic should you use when performing surgery on a calf with a simple umbilical hernia?
Procaine
32
Which incision should you make when performing surgery on a calf with a simple umbilical hernia?
Elliptical incision
33
Describe the surgical approach to surgery on a calf with a simple umbilical hernia
Dissect down the edges of the hernia ring using Metzenbaum dissection scissors to free the peritoneum
Hernial sac will fall back into the abdomen, allowing the edges to be drawn together
(Do not open sac unless incarcerated/adhesions)
34
What is the cause of an infected umbilicus/abscess outside the body wall in a calf with umbilical hernia?
A.Pyogenes or E.Coli
35
How would you treat an infected umbilicus/abscess outside the body wall in a calf with umbilical hernia?
Antibiotics eg amoxicillin +/- open abscess cavity and flush with saline/disinfectants twice daily
Need several weeks treatment to prevent recurrence
36
How would you treat a patent/infected urachus in a calf with an umbilical hernia?
Flush and give antibiotics
| May require surgery to remove urachus and infected umbilical arteries 1 or 2 stage process
37
How would you treat an infected umbilical vein in a calf with an umbilical hernia?
If doesn't extend to liver, treat as for urachus (flush/antibiotics/surgery)
If tracks to liver, can try surgery if no systemic signs-partial hepatectomy
Maruspialisation of vein out of body wall to drain abscess
Poor prognosis
38
Give some complications of umbilical hernia surgery in calves
Seroma
Re-herniation
Infection
39
Why might a cow not have come into oestrus?
- Cysts
- Persistent CL
- Nutritional anoestrus (NEB)
- Cycling but oestrus not observed/no behavioural changes
40
What would it mean if you found the following when doing a vaginal exam:
- Pus
- Clear mucous
- Blood
- Pus: endometritis
- Clear mucous: oestrus
- Blood: metoestrus
41
How big is a follicular cyst?
25mm+ diameter
42
Give the 2 types of commercial prostaglandin
- Estrumate (GnRH analogue; Cloprostomol)
| - Dinoprost (synthetic)
43
Where are prostaglandin drugs metabolised?
| Give a possible side effect
- Lungs
| - Asthma, Blackleg
44
How soon after calving does the first follicular wave occur?
5-10 days
45
How would you describe the nature of the first ovulation after calving?
Silent
46
How long does oestrus last (ie how long will a cow stand to be mounted)?
12 hours
47
Give some signs of a cow in oestrus
- Standing to be mounted (best indicator)
- Chin resting
- Licking
- Bunting
- Mounting head to head
- Sniffing vulva
48
What could you recommend to a farmer to be able to tell whether or not a cow is in heat?
- Pain/chalk/ Kamar (changes colour when mounted by another cow)
- Pedometers
- Record keeping
- Teaser bull
- Monitor progesterone
49
How long does the oestrus cycle last?
18-24 days
50
How long does it take for involution of the uterus to occur after calving?
3-4 weeks
51
What stimulates the first follicular wave post-calving?
Increase in FSH
52
How long after calving does the first oestrus occur?
2-3 weeks (unless ill/NEB)
53
Give some negative factors for using natural service over AI
- Lack of genetic variation
| - Potential for injury to both cow and bull
54
Define metritis
- Inflammation of all layers of uterus (abnormally enlarged uterus and purulent uterine discharge detectable in the vagina)
- Occurs within 21 days after calving
55
What are the 3 grades of metritis
1) Enlarged uterus, purulent uterine discharge, no pyrexia/illness
2) 'Puerperal metritis': overt systemic illness (decreased milk yield, fever >39.5oC, reduced appetite)
3) 'Toxaemic metritis': signs of toxaemia (cold extremities, dullness)
56
Define pyometra
Accumulation of purulent material within the uterine lumen, in the presence of a CL and a closed cervix
57
Define endometritis
Inflammation of functional wall of uterus (purulent uterine discharge detectable in the vagina)
Occurs after 21 days post-partum
58
Give some risk factors for uterine bacterial infection
-RFM
-Abortion
-Dystocia
-Twins
(also induction, multiparous, milk fever)
59
Which pathogens are most likely to cause uterine disease?
- E coli
- Trueperella pyogenes
- BHV-4 (endometritis)
- Dichelobacter nodosus
- Fusobacterium necrophorum
60
Give some symptoms of cystic ovarian disease
- Anoestrus
- Nymphomania (due to a pathological expression of oestrus)
- Extending calving interval
- More common <60 days post-calving
61
Describe follicular cysts
- Thin walls (<3mm)
- Fluid-filled
- Internal diameter >25mm
- Last for 10 days
62
Describe luteal cysts
- Luteinised follicular cyst
- Thick walls (>3mm; indicates progesterone production)
- External diameter >25mm
- Fluid-filled lacuna
- Last for 10 days
63
How can you diagnose uterine cysts?
- Palpation
- US
- Milk progesterone?
64
Which drug is most successful in treating endometritis?
Oxytetracycline
65
Which abortion-causing microbes have vaccines?
- Brucella
- Lepto
- BHV-1
- BVDV
66
What is the difference between a primary and secondary abortion pathogen?
- Primary: cause damage to and cross the fetomaternal barrier (eg Brucella)
- Secondary: need another agent to create damage so it can cross the fetomaternal barrier (eg salmonella)
67
When in gestation do most pathogens cause abortion?
4 months +
68
Give some primary infectious agents that cause abortion
- Brucella abortus
- BVDV
- BHV-1
- Leptospira borgpetersenii (commensal in repro tract)
- Neospora
- Parainfluenza 3
69
Give some secondary infectious agents that cause abortion
Gram +ve: streps and staphs, Staph aureus, Trueperella pyogenes, Listeria monocytogenes
Gram -ve: E coli, Fusobacterium necrophorum, Histophilus somni, Leptospira borgpetersenii, Salmonella
70
Give the 3 routes of infection for abortion
- Resident flora of repro tract during pregnancy
- Transplacenral
- Haematogenous (ie viruses)
71
What is the most common cause of abortion in cattle?
Neospora (12.5% of UK abortion)
72
What is the most likely outcome of pregnancy in a cow infected with Neospora?
Birth of clinically normal, PI calf
73
What kind of virus is BVDV?
Pestivirus
74
In which organ can Leptospirosis reside?
Kidney
75
How do you treat Leptospirosis?
- Antibiotics: prolonged course of dihydrostreptomycin or oxytetracycline
- Can control with vaccination
76
Which Salmonella serovar is most associated with bovine abortion?
S. Dublin
77
What increases shedding of Salmonella?
Stress eg around calving
78
When do you vaccinate against Salmonella?
2 months pre-calving
| Should also vaccinate youngstock
79
How would you diagnose a calf persistently infected with BVDV?
Can detect in blood from 1 month old (if <30 days, MDAs interfere)
Ear notch tissue test when tagged
80
You can do bulk milk screens for which abortion-causing pathogens?
- BVDB
- Lepto
- Neospora
- BHV-1
81
How can you identify Campylobacter as a cause of abortion?
- Preputial washing of bulls (use warm phosphate-buffered saline)
- Vaginal mucus collection (minimum of 12 samples)
82
When during pregnancy does Neospora cause abortion?
Between months 4 and 6
83
How can you use radiography to see if an aborted calf died from BVD?
Radio-opaque lines will be present on bones
84
Give a developmental lesion associated with BVD in calves
Cerebellar hypoplasia
85
When does T cell recognition of the calf's own self occur during gestation?
90-120 days gestation
86
In which ways can Neospora cause abortion?
- Cattle ingest oocytsts -> transplacental transmission -> PI calf or abortion or uninfected weak calf
- PI cow recrudesces during pregnancy -> PI calf or abortion or uninfected weak calf
87
How can you diagnose neospora in an aborted calf?
Brain histopath
88
How can you control Neospora?
Keep dogs away from cattle feed and water and don’t allow to eat placentas
Cull seropositive animals and offspring? (often not practical as high prevalence)
Breed to beef and do not keep or sell as replacement heifers
Use sexed semen to get more heifers from uninfected animals
89
What is the incubation period for BVD?
5-7 days
90
Give the likely outcomes of infection with BVD at the following gestations:
0-95 days
95-120 days
120-285 days
0-95 days: abortion or resorption
95-120 days: PI calf
120-285 days: sero-positive foetus +/- congenital lesions. Abortions may occur due to placentitis
91
Give some effects of BVD on cows
Lowered pregnancy rates (affects the epithelia lining the repro tract)
Abortion
PI calves
Congenital abnormalities (of calves affected after day 120 of gestation)
Mucosal disease
92
Give some clinical signs of mucosal disease (caused by BVD)
Ulcerations of mucosa (particularly tongue, soft palate, ginigiva & oesophagus)
Ill thrift
Diarrhoea
+/- Concurrent respiratory disease (immune suppression)
93
How is leptospirosis excreted by cows?
In urine
94
Give some clinical signs of leptospirosis in cows
```
Cow often in latent state
Abortion, stillbirth, weak calves
Infertility
RFM
Milk drop (uncommon)
```
95
How do you diagnose leptospirosis in cows?
Bulk milk antibody testing gauges level of infection in herd
Serology
Identification of leptospires from aborted tissue, blood or urine by IF or PCR
96
How is Camplylobacter fetus venerealis spread?
Venereally
97
How does Camplylobacter fetus venerealis cause infertility?
Early embryonic loss within first 3 weeks of conception
98
What is the difference between Camplylobacter fetus venerealis and Campylobacter fetus fetus?
Camplylobacter fetus venerealis causes early embryonic loss within first 3 weeks of conception
Campylobacter fetus fetus causes abortion
99
Give the clinical signs of Trichomonas fetus
Occasionally causes abortion
More commonly causes poor pregnancy rates
Pyometra and endometritis
100
How is Trichomonas fetus spread?
Natural service
101
How can you estimate gestational age of aborted foetuses?
Crown-rump length
102
Which sample would you need from an aborted calf when investigating BVD?
Spleen (PCR)
103
How do you treat Campylobacter in bulls?
Systemic: Streptomycin 10mg/kg
| Sheath lavage: 100ml pen/strep
104
How long does oestrus last in the cow?
24 hours
105
When does a cow ovulate?
12 hours after the end of oestrus
106
Which hormone is essential for embryo growth?
Progesterone
107
How do you calculate submission rate?
No of cows served / no of cows eligible
108
How do you calculate pregnancy rate?
No of cow pregnant / no of cows served
109
When can you detect a calf's heartbeat in a pregnant cow?
Day 28
110
Which endocrine changes are associated with ovarian cyst formation?
Reduced LH surge
| Persistently increased oestrogen levels
111
Give some effects of milk fever
RFM
Endometritis
Difficulty calving
112
When is a cow's peak milk yield after calving?
8 weeks after calving
113
How do follicles and CLs feel when doing a rectal examination?
Follicles: blister-like
CL: firm sponge
114
What are the 3 accessory sex glands of a bull?
```
Seminal vesicles (cranial to prostate)
Prostate
Bulbourethral gland (caudal to prostate)
```
115
How do you score endometritis based on vaginal mucus appearance?
```
0= clear/translucent mucus
1= mucus containing flecks of white or off-white pus
2= <50ml exudate containing <50% white/off-white mucopurulent material
3= >50ml exudate containing purulent material, usually white or yellow, occasionally serosanguinous (containing blood), very unpleasant odour
```
116
What does the calf embryo secrete to signal its presence? How is this different from a foal?
Calf embryo secretes interferon tau
| Foal embryo moves around the uterus
117
How do you diagnose pyoderma?
Enlarged uterus
CL
Check ultrasound for pus
118
How do you treat pyoderma?
Prostaglandin
119
Give some predisposing factors of cystic ovarian disease
```
High milk production
NEB and ketosis; raised NEFAs
Twinning and periparturient problems
Genetic predisposition
Higher parity
Excess BCS at drying off
```
120
What effects do follicular cysts have on the oestrus cycle?
Secrete oestradiol for the first half of their lifespan -> other follicles can't develop, and prolonged oestradiol inhibits the LH surge
121
What % of cows should a fertile bull get pregnant?
Should get 90% of 50 normal, cycling, disease free, females pregnant within 9 weeks
60% should become pregnant within the first 3 weeks of the breeding period
122
What BCS should a bull be at the start of the breeding period?
3 or 3.5
123
What are the treatment options for penile haematoma in a bull?
Cull
Medical: sexual rest for 2 months. Cold hosing for 4 days followed by warm hosing and massage for 3 weeks. ABs to stop abscess formation & NSAIDs
Surgical: removal of blood clot and suturing of tunica albuginea where possible. Followed by medical treatment.
124
What causes penile fibropapilloma in bulls?
Bovine papilloma virus
| Most common in young bulls
125
How do you treat penile fibropapillomas in bulls?
Removal can be done standing under a pudendal nerve block
126
What are the main venereal diseases that can be transmitted by bulls?
Campylobacter fetus venerealis
Trichomonas foetus
BHV 1
127
Give some clinical signs of Campylobacter fetus venerealis in cows
Endometritis after service
Failure to conceive
Late embryonic death (irregular return to service)
Abortion (usually 4-5 months)
128
Do cows and bulls develop immunity to Campylobacter fetus venerealis?
Cows develop immunity after a few months and can get pregnant again but may shed for up to 1 year
Bulls do not develop immunity
129
How do you diagnose Campylobacter fetus venerealis in cows and bulls?
Cows: vaginal mucus culture
Bulls: sheath washing and culture
130
What is the voluntary waiting period?
| How long should it be?
Time between calving and first service
| 50 days
131
Give some differentials for a cow that calved last night and is dull, unwilling to stand, off her food, tachycardic, with no rumen turnover
```
Hypocalcaemia (usually occurs within 72 hours of parturition)
Toxic mastitis (E.coli, Klebsiella)
Trauma at calving
Hypomagnasaemia
Ketosis (would usually happen 21 days post-calving)
Metritis
Fracture
Poisoning
Haemorrhage
Nerve/muscle damage
Hyperphosphataemia
DA (would usually happen 21 days post-calving)
```
132
Give some differentials for a cow that is 80 days post-calving and has not been seen in oestrus
```
Cystic ovary (follicular or luteal cyst)
Missed heats (poor heat detection)
Endometritis (unlikely if no vulval discharge)
Mastitis
DA
Hypocalcaemia
Persistent CL
Nutritional anoestrus (eg in NEB)
```
133
How do you treat a follicular or luteal cyst?
GnRH followed by prostaglandin 7 days later
Can use an ovulation synchronisation programme (eg GnRH, then prostaglandin 7 days later, then a second administration of GnRH 48hr later, and finally TAI 0–24 hr later)
134
Give a differential for a cow that calved 28 days ago with white muco-purulent vulval discharge
Endometritis
