While visiting an area farm at feeding time I watched the owner give her mare an extra portion of feed since she was eating for two. I know she meant well, but the mare is not due until May. I explained to her that the “extra portion” really isn’t needed – she can continue to feed her mare on a quality maintenance program, including quality forage, until her last trimester.
During this time, the foundation of the foal’s body is being built, so quality nutrition is needed, but it doesn’t put a big strain on the mare just yet. When she reaches the last part of pregnancy, the foal’s body begins to actually grow by around 1 lb per day, and that is when the demands on the mares’ reserves begin. At that point, the owner would be wise to switch to a feed specially designed for broodmares and foals, as these feeds take into account the increased needs of the mare during that last part of pregnancy, and are formulated so a regular portion can be fed instead of having to provide “extra”.
Explaining further, I told her to gradually switch the mare to a broodmare or mare and foal ration, over a period of 5-7 days. Total dietary protein – not just from the grain, but from the grain and hay both – should be 12-14% (depending on amino acid balance) and balanced for all nutrients. It is important that the concentrate portion of the diet provide adequate protein, energy, calcium and phosphorus, as well as other vitamins and minerals. The foal is pulling significantly from the mare’s supply during the end of the pregnancy, and building up stores of nutrients for the first weeks of life on the ground. For example, the foal will not receive any copper from mare’s milk, so it has to store up sufficient levels while still in the womb to last it until it begins eating solids alongside its dam.
Finally, most mare & foal feeds are designed such that the mare should continue on the ration until she is through the heaviest part of lactation, and the foal can begin eating alongside her to adjust to solid feed, then can continue on the same feed through weaning – thereby reducing at least one stressful switch at that difficult time!