Just curious! My mare who was very “silent” when not preggers now seems to have a crush on one of the other mares (not pregnant). Quite a display! Made me nervous enough to ultrasound just to be sure she was still in foal! Wondering if any breeders have noticed a correlation between a mare’s behavior while pregnant and sex of foal?
My mare right now is twice as loud and more studish then the actual stallion on the property. She has a “crush” on one mare in particular and you would swear she was a stallion when she sees her!! She in the past has been this way when she was carrying a filly (3 so far). When she had her only colt (to date 
) she litterally had urine spraying out of her if any horse so much as looked at her and/or when she was running in the field…so I guess we will have to wait and see 
She is 92 days today Good luck with your mare!!
A few years ago my mare was acting very bitchy & not her normal self while she was pregnant. The barn owner, manager & I all were discussing the thoughts on the pregnancy. We all came to the same thought at about the same time… the sex had to be a filly. Sure enough two months later my mare delivered a filly. Of course I was hoping for a colt that year but I’m super glad she was a filly now.
[QUOTE=Roisin;6445135]
Just curious! My mare who was very “silent” when not preggers now seems to have a crush on one of the other mares (not pregnant). Quite a display! Made me nervous enough to ultrasound just to be sure she was still in foal! Wondering if any breeders have noticed a correlation between a mare’s behavior while pregnant and sex of foal?[/QUOTE]
Research shows that mares that display estrus behavior while pregnant have a SLIGHTLY higher incidence of producing a filly. However, mares’ that display stallion like behavior are not more likely to produce a colt. Hope that helps!
Last year my mare was so “studdy” I had to take the yearlings out of the field as she was too rough with them, she produced a filly. This year first pregnancy was exactly same behavior, studdy and aggressive, but she lost the pregnancy. Now, she is back in foal and has not displayed any signs of studdishness or aggression- I was sure she was not in foal, but she is! I will let you know if we get a colt next year
most of my mares: if they show estrus when in foal they have a filly. If not showing…who knows. Except for one mare. That one is one that won’t “show” under any circumstances. She has silent heats. To boot EVERY SINGLE BLOOMIN’ PREGNANCY this mare has had the vet declared her not in foal on the first US…could not find it til later when she did not come back in. Three different vets over the years too. All repro experts. She hides the buggers somewhere at first. THAT one is more consistent with her behavior…she gets sweet with fillies and bitchy with colts.
This is really an interesting thought… I hadn’t thought much of it, but thinking back, my mares that have show estrus in foal have always had a filly. I haven’t really had one by studdish.
I have one this year who is about 55-60 days in foal, and a she is RIDICULOUS. Normally I keep my pregnant mares next to one of my stallions, and it’s not even remotely an issue. This mare will go tease, pee, etc… I SWORE she was open, but we just checked her last week and all is well…
Interesting theory. I would REALLY love for the mare mentioned above to have a filly.
Both of our mares who had colts this year showed very marked studly behaviour.
So interesting! Thanks for sharing your observations! My heart wants a filly, but my head wants a colt (future gelding!). Of course, I will be thrilled either way and priority is healthy foal.
Very entertaining to see the behavior changes in my mare. Takes me back to when I was “in foal”! I guess I can relate to the hormonal impact.
there is a period of time during early pregnancy i think around 90 days where there is the most production of testocerone, regardless of foal gender. from what i have read this is when mares can act like a stallion, but then the hormone and thus the behavior tapers off after roughly 120 days. My mare acted like a stallion well beyond her 5th month, and she usually very even keeled and easy going. we all swore it was a colt. sure enough, we have a big beautiful 3 month old colt now.
My mare acted very studdish when in foal. She even tried to mount ME twice! No joke. What a surprise to see her try to gently climb on my back (she was very lady-like about it!) The second time, I was ready with a crop in hand and she got the point and never tried it again. I thought it was the most peculiar thing ever. She did have a colt.
The mare this year didn’t show signs of estrus but she nickered quietly to the other horses sometimes. She had a filly. Very interesting topic.
Well, my only colt was back in 2005, the rest have been fillies! I’ve not had a mare act studdish until this year. Older maiden retired performance mare, has been a challenge to get in foal. She was very showy to my gelding prior to breeding (plastered at his face peeing). Lately she has been VERY studdish, surprisingly so. I had to seperate the two because they were fighting and not appreciative of eachothers company. She squeals and postures and then deep nickers to the mares.
I have a mare who has produced two foals for me - one colt and one filly. Both pregnancies she completely acted like a stallion to all mares in the paddock who were in heat. She mounted them and even did the thrust movements! Great ‘teaser’ pony when she is in foal haha.
In the words of Takei…oh, myyyyyyyy! We have such a G-rated little barn.
She is at 100 days and I observed the “I’m in heat” but also the stallion-like nickering. Hmmm.
The other main behavior difference is that she haaaates being brushed now. Very Princess and the Pea about it.
My mare Annie had her first foal for me this year, a filly. Although it was a big change from career gal to stay at home mom for her she was pretty easy going. This year (now about 70 days in foal) she screams like a stallion…has to be a colt, LOL!!!
[QUOTE=Equine Reproduction;6445385]
Research shows that mares that display estrus behavior while pregnant have a SLIGHTLY higher incidence of producing a filly. However, mares’ that display stallion like behavior are not more likely to produce a colt. Hope that helps![/QUOTE]
Interesting–I have definitely seen a slight correlation between behavior while pregnant and the gender of the offspring.
My limited experience with one mare (hardly statistically significant!) –
She had three colts in a row for me, and acted the same in each pregnancy… dreamy, lovey-dovey, on her own little happy cloud. I bought her bred with the first colt so I didn’t see early pregnancy behavior; with the other two I knew she was pregnant at about 2 days post-insemination because she went to that happy place. And I wasn’t the only one to notice.
In 2010 she had her first filly for me, and she wasn’t studdish but she was MISERABLE. Like the foal was causing her pain or discomfort the whole time. Lots of standing around with ears pinned. No happy place! The other thing that was odd was that she was an over-protective mom to the three boys, but let the filly interact with people or stray away from her almost from birth. It was like she was saying “you caused me 11 months of grief, you are on your own now!”
The experiment went awry in 2011… another filly, and while she was not quite as dreamy she didn’t seem anywhere near as miserable. I thought I’d get another colt.
Early days yet with the 2012 breeding/2013 foal (no 2012 foal) – she hasn’t even been checked in foal yet. She is acting a bit “happy and sappy” though, so fingers crossed!
I just looked out the window, to see my mare repeatedly mounting a pasturemate…
That’s definitely new.
My usually docile mare was bitchy for her entire pregnancy when she had a colt and her usual sweet, affectionate self when she was carrying a filly.
