Does breeding a two year old filly, affect their growth?

Question

Does breeding a two year old filly, affect their growth?

Answer 1

Depends on the filly, and how she herself was bred. In the wild, most fillies are bred as yearlings and have their first foals at age 2, and the sire is usually their own sire, because fillies will stay with their natal, or birth herd, for life, unless something happens to their dad and he dies for some reason.

Domesticated horses are different, though, and the prevailing belief in most circles (the Amish are different here) is that most fillies should not have foals until they are at least 3 or 4 years old and have had time to mature themselves. Having a foal too young can indeed stunt a filly's growth, and it can harm her in other ways, because she herself is immature. Fillies bred too young are like teenage girls who get pregnant- they carry a higher risk of delivery and pregnancy problems then older, more mature mares do. Young fillies are also more likely to abort or miscarry because their bodies just simply aren't able to handle being pregnant.  

Hope this helps.

Answer 2

It is not ideal. but would probably not do a great deal of harm as she would be mated in the wild as soon as she was sexually mature.

Ideally you should wait until she is at least 3 or 4 years of age.  Most thoroughbred fillies start to be bred from aged 4 or 5 - once they've had a few seasons to race, but those that are unraced through injury will go straight to the breeding sheds at 3 years old.

Answer 3

Yes.  Just because they are able to be bred, doesn't mean that they 'should' be bred.

Waiting for the filly to complete her growth cycle ensures that she, as a mare, will be better able to carry to full term a healthy foal.....and that it will not compromise her health to do so.

Answer 4

It could but not generally to a great degree, they may not reach the heigt they would have otherwise or may simply be delayed.

I would think that the bigger concern would be that her growing body may not produce the most optimum foal.  Like teenagers run higher risks of lower birth weights and premature births a younger filly would not be capable as an older one or even as well as she could herself if given another two years.

Answer 5

Yes.  They shouldn't have a foal until they are at least 4 or 5.

Answer 6

Fillies become sexually mature at around 18 months old, and can foal as two-year olds. However, they are still growing at this age, and pregnancy may hinder their growth. Ideally, mares should not begin breeding until four years of age (to foal at five years), although some are put in foal when they are three.