Sulfur salt blocks have generated a love/hate relationship among many cattlemen. Some love them and swear by them, then others feel they are a waste of money. It can be a bit of a headache to truly understand either side.
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, 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 this mineral
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 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. When compared to other minerals, sulfur does not typically require supplementation.
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. Moreover, it interferes with the metabolism of copper, which creates its 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 very small.
What is the purpose of a sulfur block?
As mentioned earlier sulfur is a necessary mineral for the well-being of your animal. Despite this mineral’s importance, you will rarely need to supplement it.
Under normal circumstances, the animal can get all the sulfur their body requires just from its 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 over-provide it.
The only time really that you will need a sulfur block is when you are feeding a non-nitrogen protein source such as urea. This is only so that the animal can properly digest and absorb the protein.
The microorganisms need inorganic sulfur to create the right amino acids from the NPN. The presence of sulfur improves the digestion of cellulose, namely 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 excess of them in the body.
Dangers of using a sulfur block
Since the margin between desirable and maximum levels 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.
The rumen microbes will produce too much hydrogen sulfide when sulfur consumption is too high. In the following step, the rumen wall absorbs the substance and it enters the bloodstream. An elevated level of sulfide in the blood will interfere with cellular energy production. Growth rate and appetite are two symptoms of toxicity. 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 toxicity in cattle
The best way to prevent this from occurring is to have the feedstuffs you will be providing testing. This will tell you what nutrients it will provide and what it will be lacking. If there is an excessively high amount of sulfur, such as dried distillers grains, then it would probably be in your best interest not to 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 supplement then putting out this type of block probably wouldn’t really 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 it that they could be consuming. If you are interested in learning more about the role forages play in cattle digestion then check out one of my previous articles “The Truth about what roughages do for Cattle“.
Since it can have a negative effect if there is a high amount of it 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 are provided on the tag of the block itself. This will ensure that your cattle will not be overconsuming it.
