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Re: [RC] The Great Vitamin Debate - Susan E. Garlinghouse, DVMAlso, if you're feeding extra beetpulp and nothing else then you're imbalancing your calcium/phosphorus ration. Rice bran is a good supplement to balance out the beetpulp.I'm just going by what Susan G says about beet pulp, but in my understanding, it isn't unbalanced with regard to Ca and P so much as it just doesn't HAVE a whole lot of it. No, I'm going by what Dr. Kellon says (and shows with her balancing charts). No offense to Dr. Kellon, but beware of charts that show lots of cool ratios and don't take into account basic digestive physiology. Sigh...so, here we go again. Calcium-phosphorus ratios have to be balanced so that there is sufficient phosphorus, sufficient calcium, but also more calcium than phosphorus. As long as there is *sufficient* phosphorus, you do NOT need to "balance" a ca-p ratio by adding yet more phosphorus. The reason (and this is not opinion, this is physiology) for this is because calcium is primarily absorbed in the small intestine (the front part of the GI tract), while phosphorus is absorbed throughout the length of the small and large intestine. Thus, calcium has a limited opportunity to be absorbed while at the same time potentially being bound to, and thus rendered biologically unavailable by excess phosphorus. Phosphorus, on the other hand, can still be absorbed along the length of the GI tract long after all the bioavailable calcium has either been absorbed further up the line, or rendered unavailable and thus becomes a 'spectator' as it travels through the small and large colon. As a result, excess phosphorus interferes with the bioavailability of calcium, but the opposite is **NOT** true---excess calcium does not interfere with phosphorus metabolism to any significant amount, therefore falsely "balancing" ca-p ratios by feeding phosphorus in excess of requirements does not serve any earthly good whatsoever. This doesn't mean that rations wildly in excess of calcium requirements are a good thing---primarily because excess calcium lends to a more alkaline pH in the hindgut (not optimal for a variety of reasons that I would be happy to cover at another time), and also because excess calcium creates endocrine (hormonal) imbalances that then potentiate thumps during endurance exercise. So, excess calcium isn't a good thing either, but is NOT improved in any way by just adding in more phosphorus to falsely "balance" the ratios. Now, let's talk about what excess phosphorus in the ration does do. One, the biggie in my practice area in So Cal, is that when high phosphorus feeds like bran are fed along with high proportions of high protein-and-magnesium alfalfa (extremely common in So Cal), a common sequelae is enterolith formation. Almost invariably (95% according to UC Davis), the horses with a history of chronic and repeated bouts of colic that ultimately go to surgery for removal of enteroliths are on high alfalfa and high bran or grain rations. I'd guess we're referring for surgery or euthanizing two to three horses a month to enteroliths, and it's a trend that I'm getting tired of in a hurry. Would those horses have developed enteroliths anyway if they weren't getting excess phosphorus in their ration? Maybe. Would fewer horses be developing enteroliths, developing colic and dying were they NOT fed excess phosphorus feeds? YES. Two, let's talk about what other minerals excess phosphorus *does* interfere with----namely, zinc, magnesium (again, that enterolith relationship), manganese and a few others of little significance. Of any real importance, probably not---but if it isn't doing any good, either, then what's your point? I don't mean to insult Dr. Kellon's opinions (I've never met her), but this theory in particular is clearly contraindicated by clinical literature. There are plenty of nutrition theories that, while inaccurate, at least don't actually increase the risk of GI disease and death. For God's sake, let's not perpetuate the theories that can cause actual harm and useless suffering. Dramatic, yes, and more than a little snippy because it's been a very long day and I'm tired of looking at colics that didn't have to happen. Come ride with me the next time I have to euthanize a horse with enteroliths in its guts. Then we'll talk about mathematical charts that the horses didn't read and aren't based on real world physiology. SUSAN E. GARLINGHOUSE, DVM, MS Michael S. Peralez, DVM & Associates 1005 North Santa Anita Drive Arcadia, California 91006 (626) 446-8911 http://www.shady-acres.com/susan ============================================================ Black care rarely sits behind a rider whose pace is fast enough ~ Theodore Roosevelt ridecamp.net information: http://www.endurance.net/ridecamp/ ============================================================
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