Basics/intro Flashcards
How long is bovine gestation?
283d
What type of breeders are cows?
Non-seasonal
Polyoestrus
How long is the oestrus cycle in cows?
21 days +/- 3
18-24d
How long is oestrus in a cow?
18 hrs
When does ovulation occur in cows?
24 hrs after start of oestrus
12-18 hrs after end of oestrus
How many days gestation is classed as abortion?
<270d
Should abortions be reported?
YES - always
To DEFRA/APHA
How long should you thaw an AI straw?
40 seconds
At 37 degrees
Which has more sperm in it - a sexed straw or non-sexed straw?
Sexed (2-4 million)
Non-sexed (10-12k)
What happens if a cow has AI too early?
Shorter lactation
What happens if a cow has AI in dioestrus?
Pyometra
Progesterone immunosuppressive
A fertile bull should get how many cows pregnant within what time frame?
90% of 50 healthy, cycling, disease free cows in 9 wks (90-9)
60% should be within first 3 wks
What is the rule of thumb when testing bull libido?
Should serve within 20 minutes (or ideally 10)
What gross motility score of semen is deemed acceptable?
3+
Ranges from 1-5
If a bull has some seminal abnormalities, is it acceptable to be used?
Yes - only if low number
Low numbers acceptable
(70% should be normal morphology)
What linear progressive score of bull semen (%) is deemed to be acceptable?
60+
What minimum % of bull sperm should have normal morphology to be deemed acceptable?
70+
What is used to stain sperm?
Nigrosine-eosin
What is the circumference of a 2 year old bull scortum?
34cm
Uterine torsion is usually in what direction?
Anti-clockwise
Stood behind cow
How can you tell the difference between luteal and follicular cysts on ultrasound?
Follicular = thick walled >3mm Luteal = thin walls
What is the treatment for follicular cysts?
Burst, GnRH, aspirate or leave alone
If a cow comes into heat soon after treating a follicular cyst, should you serve it?
No
Cyst may have ovulated but is old and infertile - wait until next heat
What is the treatment for a luteal cyst?
Prostaglandin
