Sulfur salt blocks have generated a love/hate relationship among cattlemen. There are ones who love them and swear by them, then there are others who feel they are a waste of money.
The ones that love them say that it helps with external parasite control. While putting sulfur powder has been shown to help in that area there is no, as far as I’m aware, no evidence that the block does that.
As with everything there are pros and cons to using them. While there is some benefit to feeding sulfur one must also be careful. You need to weigh the options yourself and decide if it could be something that will work for you.
A cow’s need for sulfur
Sulfur is a necessary mineral that is needed in order to maintain life. It can be found in every cell of the body and helps to regulate body functions.
One of the tasks that it does is it is part of the essential amino acids that make up protein. This is needed for body growth and not just in the muscle area. It can also be found in large concentrations in hair, skin, and hooves.
Now you may be thinking that with the importance that sulfur plays in a living organism that must mean that you will need to supplement with a block but that is not always true. Compared to the other minerals typically sulfur does not need to be supplemented.
A sulfur deficiency is not very common but an excess of sulfur, known as sulfur toxicity, is a more common occurrence in cattle. When there is an excess of sulfur it can cause different types of problems. It has recently come to light that it can cause different types of neurological ailments and can even cause polio in cattle. It has also been shown to interfere with the metabolism of copper, which brings it’s own problems.
Now you may be asking “just how much sulfur does my cow need?”. According to a paper from the University of Georgia the sulfur requirement is only 0.15% of intake. They also say that the maximum tolerable level is .40%. This makes the range between requirement and toxicity is very small.
When is a sulfur block needed?
As mentioned earlier sulfur is a necessary mineral for the well being of your animal. Despite this mineral’s importance it is very rare that you will need to supplement for it.
Under normal circumstances the animal can get all the sulfur their body requires just from their normal diet. They can get it from the forages they consume and depending on where you are located they can even get it from the water they drink. Because they can get it naturally it can be very easy to overprovide it.
The only time really that you will need a sulfur block is when you are feeding a non-nitrogen protein source such as an urea. This is only so that they animal can properly digest and absorb the protein.
The microorganisms will need the inorganic sulfur to create the right amino acids from the NPN. Sulfur has been shown to improve the digestion of cellulose such as methionine and cysteine.
A general recommendation is to feed a nitrogen-to-sulfur ratio of 10:1. This will allow the proper absorption of the amino acids without causing an over excess of it in the body.
Dangers of using a sulfur block
Since the margin between desirable and maximum level is so small the possibility of sulfur toxicity is very strong. The National Research Council recommends between 1500 to 2000 ppm of sulfur. Now this might not seem like much you should consider that dormant Bermuda grass can contain over 3000ppm, so you can see how easy it is to cause sulfur toxicity.
A couple of symptoms of toxicity can be reduced growth rate and appetite. Neither one of these are desirable if you are trying to grow beef.
As I mentioned earlier sulfur can also interact with the other minerals that are in the diet, such as copper. A deficiency in this can lead to things like diarrhea, light hair coats, broken bones, and infertility.
If that isn’t enough just providing the block itself won’t help you out much anyways. It will not provide the other nutrients needed because it is just salt and sulfur.
Preventing sulfur toxicity in cattle
The best way to prevent this from occurring is to have the feedstuffs you will be providing tested. This will tell you what nutrients it will provide and what it will be lacking in. If there is an excessively high amount of sulfur, such as dried distillers grains, then it would probably be in your best interest to not feed it if you already have a high amount of sulfur in your forages and water.
Unless you will be feeding a non-nitrogen protein then putting out a sulfur block probably wouldn’t be necessary. It would provide any help and in most cases the risks outweigh any potential, if any, benefits.
If there is a high amount of sulfur, like say in your water, then increasing the forage intake of your cattle to an extent can help with that. The saliva that they produce while chewing their cud can help negate the high amount of sulfur that they could be consuming. If you are interested in learning more about the role forages play in the cattle digestion then check out one of my previous articles “Roughages more important that you think”.
Since it can have a negative effect if their is a high amount of sulfur in your cow’s diet then you may need to provide some extra copper supplementation. This will prevent any deficiency in that area.
When all else fails you should follow the feeding instructions that is provided on the tag of the sulfur block. This will ensure that your cattle will not be over consuming it.
