brookcove
Posted : 1/14/2009 10:00:03 AM
I'm not picking on you Dyan or your friend, but I wanted to address this:
while they might not have gotten enough of one nutrient today.... he will get it tomorrow.
Something always nagged at the back of my mind about this concept, and not being a math oriented sort, I could never put my finger on it. Finally I read somewhere what it was. I'm a concrete person so it's easiest to use an example to illustrate:
Let's say your dog needs 118 mgs of zinc in a week (based on x mg per day per kg of weight to the power of 0.75). You feed about three pounds of chicken, which provides about 3 mg of zinc TOTAL. You throw in some beef heart for variety. A pound of beef heart supplies less than 8 mg of zinc, which is pretty darn good. You'd have to feed 14 pounds of beef heart in a week. But beef heart supplies copper at a level of 2 mg a pound. You'll go over the recommended level for copper by about double. Extra copper binds zinc. Now you are back where you started.
Not to mention the fact that I suspect there are only few people who have 35 pound dogs who COULD eat 17 pounds of meat in a week, not to mention any other ingredients.
So instead of meat you use more dense forms of energy. Enter grains and starchy veggies. But now this reduces the mineral content even more. As we've seen, it's hard to supply certain key minerals from JUST a diet of meat - reducing the meat makes this even more difficult.
If X nutrient makes up 50% of the diet and provides less than 50% of any nutrient, then there's NO WAY to make up for that other than actual substitution, or supplementation.
It doesn't seem right, but remember that dogs DO have the genetics to do fine on opportunistic eating plans - it's just that my comfort level doesn't include living with the thought that I'm playing Russian roulette with my dogs when I could do it otherwise. Knowing that it could be years or any day that one of my dogs turns out to be one in a thousand that doesn't have the ability to "get by" - I couldn't, can't, won't. Every time they had eye goop, coughed, or stumbled in their work I'd worry it was diet related. Heck, I do anyway and I'm pretty confident in my method.