This is the sixth in a series on how I'm determining what to feed my two horses. For Part IV, visit here.
In the last installment, we calculated the NSCs of Saga's ration, along with the Selenium and Vitamin E content of Red's ration. We also discussed how important it is to read feed bag labels and feed according to the recommended quantities for your horse's weight and level of work.
On your own
At this point, the really important thing to know is how to determine how much of a particular nutrient your horse is getting, and how much of that nutrient he actually needs. Finding out what your horse actually needs is a little challenging, but there are two fairly good sources I've been using:
mature horses in light work.
(for an 1100 pound horse)
|Nutrition & Feeding recommendation|
|Crude Protein||820 g/day||1.08 g/kg BW/day|
|Lysine||29 g/day||0.054 g/kg BW/day|
|Crude Fat|| -||5%|
|Calcium||25 g/day||60 mg/kg BW/day|
|Phosphorus||17.8 g/day||36 mg/kg BW/day|
|Magnesium||9.4 g/day||19 mg/kg BW/day|
|Iron||335 mg/day||0.8 mg/kg BW/day|
|Potassium||31 g/day||57 mg/kg BW/day|
|Copper||84 mg/day||0.2 ppm/kg BW/day|
|Zinc||335 mg/day||0.8 ppm/kg BW/day|
|Manganese||335 mg/day||0.8 ppm/kg BW/day|
|Selenium||0.8 mg/day||0.002 mg/kg BW/day|
|Vitamin A||22500 IU/day||45 mg/kg BW/day|
|Vitamin D||2510 IU/day||6.6 mg/kg BW/day|
|Vitamin E||669 IU/day||1.6 mg/kg BW/day|
|Biotin||-||0.2 mg/kg BW/day|
|Iodine||-||0.007 mg/kg BW/day|
|Cobalt||-||0.001 mg/kg BW/day|
|Thiamine||-||0.06 mg/kg BW/day|
|Riboflavin||-||0.04 mg/kg BW/day|
And now, more math
I promised to calculate the quantity of protein, fat, calcium, and phosphorous that the boys were getting, since these are often the nutrients people look at most. For simplicity, I'll do all the calculations for Saga, and assume he weighs 500 kg.
Saga should get between 540 and 820 g/day of protein.
- Purina Ultium is 11.7% protein, and Saga gets 9 lbs of it daily. That's a total of 1.053 lbs of protein/day (9 lbs x .117)
- Bermuda hay is 10.6% protein, and Saga gets 15 lbs of it daily. That's a total of 1.59 lbs of protein/day (15 lbs x .106)
- Add these together and you get 2.643 lbs of protein/day. Converted to grams, that's 1198.844 g/protein/day. He's definitely not hurting for protein!
- Purina Ultium is 12.4% fat, and Saga gets 9 lbs of it daily. That's 1.116 lbs of fat/day (9 lbs x .124)
- Bermuda hay is 1.8% fat, and Saga gets 15 lbs of it daily. That's a total of 0.27 lbs of fat/day (15 lbs x .018)
- Add these together and you get 1.386 lbs of fat/day. Since he gets a total of 24 lbs of feed daily, that's 5.8% fat/day. So, he's right in line.
- Purina Ultium is 0.85 - 1.0% Calcium, and Saga gets 9 lbs of it daily. That's 0.07 - 0.09 lbs of Calcium/day.
- Bermuda hay averages 0.5% Calcium, and Saga gets 15 lbs of it daily. That's a total of 0.075 lbs of Calcium/day.
- Add these together and you get 0.145 - 0.165 lbs of Calcium/day. Convert to grams and you get between 65.7 - 74.8 g/day. That's more than double what he's supposed to get. But what's really important is that he is getting a Ca:P ratio of about 2:1. So let's calculate P.
- Purina Ultium is 0.5% Phosporous, and Saga gets 9 lbs of it daily. That's 0.045 lbs of Phosporous/day.
- Bermuda hay averages 0.19% Phosporous, and Saga gets 15 lbs of it daily. That's a total of 0.0285 lbs of Phosporous/day.
- Add these together and you get 0.0735 lbs of Phosporous/day. Convert to grams and you get between 33.3 g/day. That's more than a third more than what he's supposed to get. However, if he's getting ~66 g of Calcium/day, then the ratios of the two minerals are about right.