17.4.1: Introduction to farm animal reproduction Flashcards
True/false: you can tell about the cow’s cyclicity from her cervix.
False
Cervix tone is discussed in horses but not in cows
Dominant follicle
* Contains oocyte
* Fluid filled (anechoic on ultrasound)
* Secretes oestradiol -> this drived oestrus
Corpus luteum
* Highly vascularised transient endocrine gland
* Solid (homogenous, medium echogenicity)
* Produces progesterone
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High levels of which hormone lead to an LH surge? What is the effect of the LH surge?
Oestradiol
Effect of LH surge = ovulation
How long is the oestrus cycle in the cow?
How long is the luteal phase?
How long does standing oestrus last?
You see a cow showing signs of oestrus. When should you AI?
Oestrus lasts ~ 1 day so ASAP!
In an ideal world, would AI 6hrs after the onset of oestrus; in practice, just AI as soon as you see oestrus.
What will the ovaries feel like when a cow is on Day 1 of her cycle?
Day 1 = ovulation has just occurred
The ovaries will be small and it might be hard to palpate the tiny CL
If you see a large CL and a large follicle present at the same time, which one is dominant?
The CL
Which structures can you see on this ovary?
There is a small follicle (anechoic structure)
Which structures can you see on this ovary? Which is likely to be dominant?
What phase of her cycle is this cow in?
Follicular phase
These two ovaries are from the same cow. What phase of her cycle is she in? Which structure will be dominant?
- She is mid-luteal phase
- She has a large follicle but the CL will dominate
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