Feeding Stored Colostrum
Hopefully, everyone that breeds horses knows the importance of colostrum. Unlike human babies, foals don't get antibodies from their dam before they're born. They need to drink colostrum, the antibody-laden first-milk, to get these antibodies which help fight off early infections. Failure to get adequate antibodies from the mare, known as failure of passive transfer (FPT) of maternal antibodies, is a life-threatening problem that needs to be treated quickly. Like most things, prevention is better than treatment, so efforts aimed at reducing failure of passive transfer are critical.
In the vast majority of foalings, things go well: the foal comes out on its own, gets up in a normal period of time, starts nursing and ingests an adequate volume of good quality colostrum.
Sometimes, an adequate volume of good quality colostrum is not available. This can be because the mare leaked colostrum before foaling, the mare didn't produce colostrum, the mare rejected the foal or the mare died during foaling. Whatever the reason, lack of colostrum is an emergency and needs to be addressed promptly to reduce the risk of serious infections. There are a few possible ways to do this:
- Get colostrum from another mare that has just foaled: Great idea, but difficult in practice unless you have a large farm or a network of other local breeders that might have a mare who just foaled and has colostrum to spare.
- Commercial colostrum replacers: Not a great option. They're very convenient, and likely better than nothing if all other options are exhausted, but they just don't do the job like the real thing.
- Plasma: Plasma can be given orally in the first 18-24 hours of life or intravenously after that, to provide antibodies. It doesn't replace all the goodies found in colostrum, and it's expensive, but it's often the best option available to most people.
- Stored colostrum: Banking colostrum by collecting and freezing extra colostrum from mares (or all the colostrum from mares whose foals died during birth) is a cheap and relatively easy approach. It's easiest for large farms with lots of mares, but anyone can do it. (Remember, however, not to deprive a live foal of any of the colostrum it needs so you can build up a store. Some mares may only produce enough colostrum for their own foals.) For stored colostrum to be useful, however, it must retain its beneficial properties during storage.
A recent paper in the Journal of the American Veterinary Medical Association (Nath et al 2010) looked at this aspect. They checked colostrum quality in mares at the time of foaling, and if poor quality colostrum was identified, foals were supplemented with stored, frozen colostrum within six hours of birth. Blood antibody levels were checked 24 hours after treatment. Overall, 5.8% of foals had suboptimal antibody levels, but only one foal (0.4%) had true failure of passive transfer of maternal antibodies, with antibody levels <400 mg/dL. The rest of the "low" group had partial failure of passive transfer, meaning they had lower than ideal (400-800 mg/dl) antibody levels, but these levels are not necessarily a problem, particularly in an otherwise healthy foal on a well-managed farm.
It's not exactly an earth-shattering study, and only limited conclusions can be made because of some aspects of study design (e.g. not proving that supplementation was the reason that foals had adequate antibody levels, no statistical comparison of the incidence of failure of passive transfer between foals that were or were not supplemented, treating some foals that didn't fit the study criteria and not treated a couple that did), however this study showed that this type of approach - checking colostrum of mares at birth and supplementing foals whose mares produce poor colostrum - is a practical approach and resulted in a very low percentage of foals with inadequate antibody levels.
The take home message, perhaps, is that you need to pay attention to colostrum quality. If you check colostrum quality of mares that have just foaled and intervene in situations when poor quality colostrum is present, or when the foal can't/won't ingest an adequate amount of colostrum, you can make sure that failure of passive transfer of maternal antibiotics is a rare event.
More information about colostrum management is available on the equIDblog Resources page and in our archives.
