Cases: Putting it together

Estrus behavior is influenced by the physiology of the mare (hormones) and the environment (teasing situation, individual temperament of the mare, stress, etc.). Below is a list of different circumstances and how the teasing behavior may change.

Maiden – Mares that have never foaled will often will show estrus at a distance but reject the stallion out of fear of contact.

Mares with foals – Mares with young foals will often aggressively reject the stallion as he approaches. All foals should be standing before the stallion enters the barn to prevent injury caused by mares inadvertently stepping on a foal as they charge at the stallion.

Stress- Mares will often fail to tease if under stress. Sources of stress include long trailer rides, recent introduction into a group, any other source of excitement.

Pregnancy- Pregnant mares will often show estrus-like behavior when teased, especially at around the second month. This behavior is usually less evident than that which was exhibited during estrus.

Read the cases below and answer the questions.

Case 1 It is March. Your mares do not have supplemental lighting (there are no lights in your barn). One of your mares is very aggressive towards the stallion (biting, kicking, ears back) when you tease but often winks after you have taken the stallion away from the stall.	Which of the following are likely explanations for the mare's behavior? Select all that apply. She has many small follicles growing on her ovary. She is transitional at the present time. She is under the influence of progesterone. She has low levels of melatonin. Can a transitional mare have high levels of progesterone? True False
Case 2 It is June. You have bought a mare at auction. You have no records on her reproductive history but she has a fantastic pedigree and great conformation. You want to breed her to your young, inexperienced stallion but you have been teasing her every day for a month and she has not been in estrus. You haven't had time to have a breeding soundness exam.	Which of the following statements might be correct? Select all that apply. The mare is pregnant. The mare does not like your stallion. The mare had her ovaries removed (spayed) to enhance her performance. The mare may have a genetic abnormality such as being an XY female. You should have the Veterinarian examine the mare immediately. True False
Case 3 The veterinarian has told you that your mare was in foal when he palpated 45 days ago. You notice today that your mare is interested in the stallion and is hanging around the stallion's pen. She displays very weak signs of estrus. You know that estrus behavior requires high estrogen levels.	Can pregnant mares have high estrogen levels in a normal pregnancy? True False What should you do? Select all that apply. Rebreed the mare. Wait to see if the estrus behavior gets stronger. Have the veterinarian recheck the mare;s pregnancy status. Ignore your observation.
Congratulations, You have finished the laboratory!