Hormone Manipulation: Case 1

You are correct, that was not a good idea. You did not want to order semen today and breed tomorrow.

You decide to continue checking heat on this mare. There is no change in her behavior to a stallion until February 28. On this date the mare is winking, urinating and exhibiting lordosis upon exposure to a stallion. You have the veterinarian look at the mare on March 1 and a 36 mm follicle with other small follicles (<15 mm) is found on the right with a 34mm follicle along with other small follicles (<15 mm) on the left. In addition a uterine edema score of 3.0 was given (scale is 0 = none to 3=extensive).

Answer the questions below before proceding. Consider today as March 1.

At what size does the "average" follicle ovulate?

< 20 mm
20-30 mm
40-55 mm
>60 mm

How fast does the "average" follicle grow?

1 cm/day
2-3 cm/day
5 cm/day
2-4 mm/day

Based on the growth rate of a follicle, when will this mare ovulate if she is not given any other hormones.

today.
tommorrow.
2 days.
5 days.

You now decide that you want to give your mare HCG today, and breed her tommorrow. Since you live within a 3 hour drive of the stallion, you will just go down and pick up the semen. The semen you are requesting is what is considered "fresh semen". When you call to enquire about getting the semen, you are told that will be fine but you can only get one breeding dose and it will be at room temperature when you pick it up. This means that you must breed tommorrow as you will not be able to hold the semen over for another day. To cool semen would require more sperm and a different extender, neither of which the semen provider can give you tomorrow. Is this going to work?