Why does a mare make bag?

Answer by  doc325 (454)

A mare will form a bag when she is preapareing to foal. The bag contains the milk that will give life to the newborn foal. If the mare fails to "bag up" than the foal will be deprived of vital nutrients and may not survive.

Answer by  horseylady (49)

A mare 'makes bag' means the udders fill up with milk, they can 'make bag' upto a month before she is about to foal or at the last possible moment, every mare is different but if it is her first foal it is likely that she will 'make bag' earlier rather than later.

Answer by  MrsShannonHarrell (768)

Mares will bag with colostrum shortly before foaling. This ensures the arriving foal will have the proper nutrients. A mare with no bag will not be able to provide the colostrum, which needs to be addressed by a veterinarian.

Answer by  crash0708 (83)

Usually "bagging up" refers to a pregnant mare who is getting close to foaling. Her udder will bag up the closer that she is to the foaling. Right before the onset, she will have a very full udder with small amount of "waxing" or fluid coming out of the udder.