image In my continued musing over mineral supplementation for sheep and how Pat Coleby’s book and advice fit into that, I decided to do the rest of the “label” calculations for her mix, to compare to the Purina Goat Chow mix that’s working so well for me. I desired to be able to do an apples-to-applies comparison of Pat’s mix to what I can buy pre-mixed.

A Theoretical Pat Coleby Label

So, below I’ve made a table, and have hopefully correctly done the math to compare Pat’s mix to my Purina mix. The math is all variation on a theme for what I did with the copper calculations in this post. This first table is a “label” table, meaning that I just calculated what the concentrations are in the mix itself. The second table below accounts for my sheep’s consumption of the supplements and their hay intake, with notes on what our forage already has.

I’ve given kelp its own column, to see how it contributes to the PC mix, and what it’s offering if it’s fed standalone, as many people, and I, do. Kelp is harvested from nature, so its nutrient values are going to vary and cannot be guaranteed. The values I used came from Thorvin’s website and off the label of Thorvin kelp bag I have now. The calcium and magnesium numbers I’m using for the PC mix calcs are based on the brand of dolomite I’m purchasing; different brands have different ratios.

Purina Goat Chow Supp

Thorvin Kelp

Pat Coleby Sheep Mix

Comments

Salt

45%

9%

0.99%

Sheep need salt, but some mixes are mostly salt, which is a waste of $$.

Zinc

7,500 ppm

12 ppm

1.2 ppm

Zinc is important for foot health. It binds with copper and iron, however.
Iron

622 ppm

68 ppm It binds with copper.
Manganese

60 ppm

6.6 ppm
Magnesium

1%

0.85%

7.53%

PC mix gets more from the dolomite.
Iodine

0.05%

0.01%

Cobalt

4 ppm

0.44 ppm

Selenium

25-30 ppm

0.3 ppm

0.033 ppm I had concerns about excess here, will discuss more later.
Calcium

9-11%

2%

14%

Too much binds with Phos, can cause bone/urinary probs. PC mix gets more from the dolomite.
Phosphorus

8%

0.1%

0.01%

Bind with Calcium.

Potassium

0.1%

2%

0.22%

Hi levels block Magnesium & risk grass tetany. But also binds w/ iron.
Copper

1,750 – 1,800 ppm

4 ppm

27,027 ppm

Sheep are very sensitive to copper toxicity, so caution is needed.
Molybdenum

2 ppm

0.22 ppm Binds w/ copper.
Chlorine

6.5%

0.72%

Sulfur

2.8%

12.2%

Important for foot health. Binds with copper, Se and thiamine (vit B).
Aluminum

289 ppm

31.8 ppm

Boron

98 ppm

11 ppm

Vitamin A

140,000 IU/lb

Vitamin D

IU/lb

Should get enough from the sun?
Vitamin E

750 IU/lb

Bound up by iron, good for feet, so more is better for us. Green grass has plenty, but dry hay is low.
Feed rate

.25-.33 oz

0.5 oz

5 mg

Recommended feed rate for sheep.

As-Fed Values for My Sheep

Next, I calculated the as-fed values for my sheep. My sheep are currently eating about four pounds of hay per day each; and am calculating mineral concentration based on a) Pat’s recommended 5g of her mix per day, b) what my sheep are actually choosing to eat of the Purina mix: 1.6oz per sheep per day, which is more than what Purina recommends on the label for goats and c) what my sheep are choosing to eat of the kelp, which is about the same as the mineral, and more than what Thorvin recommends for sheep.

Our forage profile is perhaps a little unusual, so my choices of which minerals I want and don’t want are probably not typical. But here is where the rubber meets the road in determining how these supplements line up with my grass profile.

Purina As-Fed Thorvin Kelp As-Fed Pat Coleby Mix As-Fed Comments
Salt

10,995 ppm

2,199 ppm

27.35 ppm

I’m not sure what adequate amounts are?
Zinc

183 ppm

0.29 ppm

0.004 ppm

10+ in diet is adequate, we are already high (37 ppm), and zinc depresses copper. So I’d prefer to avoid.
Iron

15.2 ppm

0.19 ppm

50 ppm is recommended, our forage is 597. Levels above 400 tie up copper, so I want to avoid more of this.
Manganese

1.47 ppm

0.02 ppm

40 adequate, our forage is at 78, so this is a don’t-care for us.
Magnesium

0.02%

0.02%

0.02%

0.1 % recommended, 0.4% is max. Our forage has 0.24% so we’re already OK. But would be concerning if one’s forage was low…
Iodine

12 ppm

0.15 ppm

Cobalt

0.1 ppm

0.001 ppm

Selenium

0.73 ppm

0.01 ppm

0.0001 ppm

0.1 is deficient, 2ppm is too high- a very narrow range! Our NW soils are known to be deficient, so we have to add this.
Calcium

0.27%

0.05%

0.04%

PC mix is getting more from the dolomite. 0.4% is adequate, our forage has 0.53%. Too much causes bone/urinary probs, so want to avoid adding too much of this.
Phosphorus

0.2%

0.002%

0.3% is recommended, our forage has 0.32%. Binds w/ calcium. Our Ca:Phos ratio, in forage + supps, is 1.5, which is in the ideal range.
Potassium

0.002%

0.05%

0.65% recommended, 3% max; too high can bind with Potassium, causes grass tetany. Our forage is 3.19%, so I want to avoid more of this.
Copper

44 ppm

0.1 ppm

61.7 ppm

7-10ppm normally recommended for sheep, 14-20 if soil is high in Molybdenum. Since we have other copper-binders, our need is probably greater. Great caution must be exercised here, due to risk of toxicity.
Molybdenum

0.05 ppm 0.001 ppm Ideal is below 1ppm, above 4 causes copper tie-up. Our forage is at 4, so I want to avoid more.
Chlorine 1,588 ppm 20 ppm
Sulfur

0.07%

0.03%

0.1% recommended, 0.4% is max. Our forage is at 0.36%, so this is another don’t-care for us.
Aluminum

7 ppm

0.09 ppm

Boron

2 ppm

0.03 ppm

My Personal Conclusions

The interesting thing about Pat Coleby’s mix is that it doesn’t have as many added minerals as many commercial mixes do. I assume that she’s relying on the fact that kelp contains a plethora of trace minerals, and she’s only choosing to add a few key minerals that she feels are needed in higher concentration. The kelp makes up about 11% of the mix, so its nutrients translate by that ratio. But I find that to be quite small—the kelp’s nutrients fed in this quantity end up being almost negligible!

So, I think I’m going to continue to always present kelp standalone and free-choice, so the sheep have the most opportunity to get what they need out of all that kelp offers. There seems to be little risk of the sheep getting too much of something from the kelp, so I think it’s best to let them have as much as they crave (despite, perhaps, the cost!).

Since we already have adequate sulfur in our grass, if I did use the Pat Coleby mix, I’d probably omit that ingredient. The calcium and magnesium delivered via dolomite in the Pat Coleby mix are also things we don’t need, they only offer negligible amounts on top of our already-adequate amounts.

That leaves the copper in Pat’s mix, which in my opinion, is dangerously high for sheep, even despite her assertions that the calcium/magnesium quantities in the dolomite somehow buffer it. I could alter the ratio of copper to dolomite in Pat’s mix to dilute the copper concentration, but I see two problems with this. One, I’m not sure if the sheep would eat an almost pure dolomite solution, I suspect it doesn’t taste good. And two, I don’t want to get carried away with how much extra calcium and magnesium my sheep are getting, since that could cause other problems. So, in the end, I’m much more comfortable with the amount of copper offered by the Purina mix, for now.

But, when I compare the Purina mix to the kelp, all that it’s really offering me that I don’t already have is copper, selenium, salt, and vitamins A, D and E. Salt is easy to offer standalone, and I’m not sure if we really need the extra vitamins. So, now I’m starting to see, that my supplementation needs really come down to these two ingredients: copper and selenium. So I’m going to focus some more research on this. I’m considering whether purchasing a selenium/vitamin E mix for horses, and offering copper sulfate diluted in water, might be the best road for me.

In the end, I’ve decided the Pat Coleby mix isn’t right for my pasture. I still think her book is excellent, it’s what got me started in digging into this subject so deeply. And I think it may have led me to the solution for my hoof rot problems, which is huge. The book is well worth owning as a reference manual, to look up what all the minerals do, and to remind us of the notion of animals naturally craving what their bodies need. And I can’t discount Pat’s experience, that she’s worked with thousands of sheep over many decades with good success. So I think she’s definitely onto something.

But, I think it’s really just the case that mineral supplementation is complicated, and if you really want to do it right, you can’t just follow one person’s, or one company’s advice on what is a good supplement for everybody. There is no single label that’s perfect for every animal species, every sheep breed, every pasture, or every case.

Note: edited 2/20/13 to correct for some math errors accounted for in my other post about copper calcs

Advertisements