Therio- Mare Breeding management

wilsbach's version from 2015-11-15 02:33


Question Answer
what are the two types of natural breeding?(1) Pasture breeding (not common) (2) Assisted breeding ("Live cover")
three types/ways to handle semen for AI?fresh, cooled and shipped, frozen.
what is pasture breeding?where you just let them naturally breed out in the pasture
explain how live cover breeding is doneMare is teased daily or every other day--> When she is in good heat, she is covered. She is teased again 2 days later and re-covered if she is still standing. Cont. until mare rejects the stallion
what is the only kind of breeding allowed in TBs?live cover
why is ovulation timing critical for live cover breeding?One cover per estrous cycle ("covering fee") therefore ovulation timing critical!! (induction of ovulation...)
do you bring the mares to the stallions, or the stallions to the mares for live cover?Mares will visit stallion at stud
what are some ways to insure the safety of the stud during live cover?mare is hobbled, twitched, has non-kick boots on
*what is the insemination dose for fresh or chilled semen?500 million progressively motile, morphologically normal spermatozoa
how long is semen good for once it is extended?+/-24hr
what is the special container in which the semen is placed and shipped after it is extended for AI?"Equitainer" or "Clipper"
when inseminating the mare during AI, what are some ways to maintain hygiene?tail bandage/wrap, clean perineum with water & mild soap (not betadine) & rinse well. sterile rectal glove (inside out or autoclaved)
once you are thoroughly cleaned and you have the sterile rectal glove on, how do you AI her?arm passed to the cervix and insemination pipette passed intrauterine & semen deposited-- massage cervix - oxytocin release. hand withdrawn slowly to avoid getting air in vagina
since you want to ensure that ovulation occurs ASAP after insemination ie. within 24-48h... you can induce ovulation with what two agents?(1) hCG - Chorulon (2) GnRH analogues
what does hCG do, and when do you want to use this? how long till intended effect?use to INDUCE OVULATION! Bc has LH like effect. You want to use this when follicle is >or equal to 35mm--> ovulation within 36hrs!!
what do GnRH analogues do, how long till intended effect?used to INDUCE OVULATION (can be ovuplant implant, or Sucromate/Fertagyl injection) get ovulation within 42h
*for how long is frozen and then thawed semen good for?Frozen thawed semen is fertile in the mare for a maximum of 12 hrs
*how long is the ovum good for after ovulation?After ovulation, the oocyte viable for a 6-12 h period
**since frozen semen is only good for max 12hr, and oocyte is only good for 6-12h after ovulation...what are the goals for when you wanna inseminate the mare with frozen semen?Therefore the goal is to inseminate the mare in the window 12h BEFORE ovulation and 12 h AFTER ovulation
explain how to go about insemination once you have given the hCG injection?start examining the mare every 6-12h starting 12h after hCG injection until ovulation has occurred. Inseminate immediately AFTER diagnosis of ovulation by deep intrauterine insemination (on the side with the follicle).
why do you wanna do foal heat breeding?In order to get mare pregnant again ASAP so that she can foal down as close to 1st January as possible
after foaling, when is the first ovulation? when does uterine involution happen?First ovulation between 4 and 14 days postpartum (average 10 days). Uterine involution takes >12d
how long does uterine involution take?greater than 12d
what are the downsides of foal heat breeding?Fertility (% pregnant) is lower (-10%), Risk for early embryonic loss is higher (+10%)
what will happen if you skip the first ovulation of the foal heat breeding? (how long till you can breed?)will then only be breeding +/- 20 days after foaling and may push back next year's foaling date
why might you not want to inseminate during the foal heat?Uterus not involuted properly, high risk of EED
how can you postpone the first ovulation of the foal heat?Using progesterone (Regumate) from foaling until +/- 12 days post foaling and then inseminate when mare shows heat
If you decide to skip the first foal heat ovulation, how can you still shorten your wait period? (when would you breed then?)Skip first ovulation and give PGF to shorten the luteal phase-- Mare is then bred +/-D14 after foaling
Examine the teasing record of the following TB mare. What treatment was given on 27th February? PGF2α
what treatment is given on the 6th March? hCG
You examine a mare due to be bred by live cover. You find the following structure on the ovary. At what stage of the cycle is this mare? This is a US of a CL, so she is in diestrus
Examine the following two images of the uterus of a mare obtained on rectal ultrasound scan on two successive examinations with an interval of 8 days. Which ultrasonogram is typically associated with low uterine tone? A
Examine the following two images of the uterus of a mare obtained on rectal ultrasound scan on two successive examinations with an interval of 8 days. Artificial insemination with fresh semen is more likely to be indicated on the day you observe which ultrasonogram? A

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