>>> I've done research on older mares and found there is only 30% chance she is prego if covered only once, I'm sure she was covered more just not sure how successful he was. Does anyone know the likelyhood of the little guy getting it right more than a couple times?
I think I found the article you read-- It refers to older mares needing to be bred "twice as often" to achieve a pregnancy-- - IMO that means an older mare on average needs to be bred twice as many cycles as compared to a younger mare to get pregnant-- NOT that during each cycle, the mare needs twice as many covers.
In most cases, It only takes ONE cover at the right time to impregnate a mare, no matter the mare's age.
Sperm only live so long, so if one breeding took place at the optimum time in relation to the mare's ovulation, so that the sperm were alive and active when they reached a fertile ovulating egg, then pregnancy would be achieved from that one cover. Any covers made too early before ovulation would mean less chance of conceiving, because the sperm would be weaker or dead--they would have swum up the reproductive tract of the mare, but would have to "wait around" for ovulation.... any covers made after the mare ovulated would mean the egg was already on its way out or already gone and the sperm could have completely missed it.
Said another way-- just because a mare is older does not mean that "banking" sperm in her reproductive tract by multiple covers would be of any benefit as far as rate of conception... because if the sperm are viable, timing is much more important than volume or frequency.
Also, being covered more often than necessary can have adverse affects-- pathogens, germs, debri, etc are potentially introduced in the reproductive tract more often, and some mares actually have sort of an allergic reaction to semen, which can cause inflammation of the uterine lining, failure to expell excess fluid from the uterus, etc..... meaning, in some older mares, for optimum chances of a pregnancy, the less covers the better-- as long as the cover or covers that ARE made are well timed.
Last edited by Eastowest; 04-09-2010 at 07:12 PM.