Why Do Cows Need Salt? How Much and How Often?

Dietary needs of cows (1)

Whether you have a single dairy cow, a small herd of beef cows, or a large operation, it’s important to understand the mineral needs of cows. In the wild, cows will find natural sources of salt, but in modern farming, they are usually confined by fences. 

Why do cows need salt? Cows need salt to perform basic metabolism and other bodily functions. Dairy cows need salt to create milk and beef cows need salt to put on their proper weight. Calves with a salt deficiency have a much lower weaning weight than calves with access to salt. 

Like other animals, cows use salt for the maintenance of their bones, muscles and nervous systems. 

But, they can’t store it. So cows need daily access to salt to maintain proper health. 

This article will cover how much salt cows need, based on the type and age of the cattle. We’ll also cover signs of salt deficiencies in cattle and types of salt supplements. 

Benefits Of Salt To Cows

Salt helps cows with many body functions. 

Salt is really the common name for sodium chloride. Sodium helps to regulate the blood’s PH levels in cows. Chloride helps digestion. (That’s part of why cows lose weight when they are low on salt)

Calves need salt to help their body’s to build strong bones. It also helps them to have regular heartbeats. 

Salt helps with blood clotting. 

It also helps with muscle movement. 

Signs That Cows Don’t Have Enough Salt In Their Diets 

There are many clues that your cows may need access to more salt. One of the first signs of salt deficiency is weight loss. 

Another sign is when cows develop pica. 

Pica happens when cows start eating odd things such as dirt, rocks, wood, or the carcasses of other animals. None of these things are natural food for cows so if you see your cows eating odd food, it’s a sign of salt deficiency. 

Plus, there are a number of diseases that occur when cows are low on salt. I’ll cover those in the next section. 

Rough coats will also signal a salt deficiency in cattle. Other symptoms may include decreased appetite, excessive water consumption, and increased urine. 

  • Weight loss in cows
  • Pica: Eating unnatural things to get salt 
  • Development of diseases caused by insufficient salt intake 
  • Rough coats
  • Increase water consumption and increased urine output

Cow Diseases Caused By Salt-Deficiency

Cows can have many health issues caused by too little salt. 

Milk fever occurs when lactating cows don’t get enough salt. They can have a hard time standing. Contrary to the name, cows with milk fever have too low body temperature. 

Milk fever is caused by the cow producing more calcium than she intakes. 

Many dairy farmers will use calcium salt gel to prevent milk fever. 

Rickets is a bone disease. It causes soft bones and as the disease progresses, it impairs movement. Abnormal bone growth can occur in calves with a salt deficiency. 

Tetany is caused by magnesium deficiency. Since magnesium is usually obtained through the salt, it can be prevented with a salt and mineral supplement.
Tetany is scary because it can cause sudden death in dairy cows with no warning symptoms of any kind. It causes abortions of mid-term fetuses. Near-term fetuses often are born prematurely, which also increases fatalities. 

It happens most often when dairy cows graze in young pastures. New grass has a different nutritional composition than older pastures. 

It’s also preventable by providing those same cows with a salt supplement that has a trace of magnesium. 

Cows on pasture have different salt needs depending on the time of the year (1)

Sudden climate changes can also affect grazing areas by creating grass with high potassium. Spikes of potassium is known to increase tetany. This happens during repeated freeze-and-thaw springs. It can also happen when an area of drought suddenly gets tons of rain. 

Magnesium, sodium, and calcium in the grass decreases and the potassium increases. 

Cattle feeding in these types of pastures rarely get tetany when they have free access to a salt and mineral mix. Cattle with only magnesium supplements and no salt supplements still tend to get tetany.  

White Muscle Disease causes calves to die shortly after birth. Symptoms include lameness or an inability to stand. Other symptoms include heart failure. 

An autopsy will show that the calf’s muscles look white instead of red. 

Downer Cow Syndrome is the name given to cows that look depressed or down. Cows will be more lethargic. They go down and won’t rise when they should. Recumbency occurs when cows won’t get up. 

After 24 hours down or recumbent, cows can develop other health issues that cause them to stay down. 

Not all cases of downer cow syndrome are caused by a lack of salt, but many of them are. 

  • Milk Fever
  • Rickets
  • Tetany
  • White Muscle Disease
  • Downer Cow Syndrome


What Kind Of Salt Is Best For Cows? 

Salt supplements come with different trace minerals and in block or lose form. In the spring, summer, and fall, salt blocks are an easy way to provide salt to your cattle. But, when temperatures get below zero, salt blocks become uncomfortable for cattle to lick. 

It’s a lot like licking a cold flagpole. 

In freezing temperatures, loose salt often works best for cattle. 

When cattle are in dire need of salt, salt blocks usually don’t provide enough salt. Additional supplements of loose salt is needed to keep cattle safe and healthy. 

The tongues of cattle don’t do a great job of getting all the salt they need from just salt blocks. Instead, cattle will eat about twice as much salt if they have access to loose salt instead of just salt blocks. 

Salt generally comes with various trace minerals. 

Blue salt contains iodine and cobalt. Blue salt supplements are commonly used in the prairies. Brown salt contains traces of copper, magnesium, zinc, and selenium.

It’s helpful to provide a salt and mineral supplement because cows will generally seek out enough salt, but rarely seek out independent minerals that they need. 

Plus, some of those minerals taste bitter so they aren’t as desirable to cows. Still, it’s important for you to provide the right balance of other nutrients to your cows. 

A salt and mineral supplement makes it easier for your cows to get all the minerals they need. 

Salt supplements should be relatively close to water. Salt intake will increase the amount of water that your cows need and it’s important they have easy access to it. 

  • Salt with trace minerals help cattle to get the additional minerals they need
  • Loose salt is easier for cattle to eat than salt blocks

How Much Salt Do Cows Need? 

As a general rule cattle need about 0.1% of their daily intake to be salt. But, this can vary depending on the size and activities of the cows. 

That means that a 1400 lb cow usually needs between 35-45 grams of salt a day. If you have about 100 cattle, they will go through 55 lbs of salt each week. 

Another way to estimate the needed salt for your cattle is to calculate it against your cattle’s body weight. A cow will eat about 0.005-0.010% of their body weight in salt a day. 

Again, this is a general rule. 

Beef cows will consume more salt during periods of greater activity. In addition, when your herd is calving or lactating, they will also need more salt in their diets. 

Dairy cows will often need more salt as well. 

Can cows eat too much salt? Cows naturally eat the amount of salt they need in their diets. Even with constant access to salt, cattle will not overeat salt. It is far more common for cows to not have access to salt that they need for optimal health. 

What Other Minerals Do Cattle Need? 

Cows need a combination of micro and macronutrients to stay healthy. As already mentioned, many of those minerals can be found in salt blocks with trace minerals included. 

Macromineral requirements for cattle: Cattle need calcium, magnesium, phosphorus,  and sulfur. 

Mineral Lactating Cows Dry Cows Growing Calves Maximum Levels
Calcium 0.31% 0.18% 0.58%
Magnesium 0.10% 0.12% 0.20% 0.40%
Phosphorus 0.21% 0.16% 0.26%
Sulfur 0.15% 0.15% 0.15% 0.40%

Micromineral requirements for cattle: Cattle need an additional 10 microminerals for a healthy diet. These minerals include cobalt, copper, iodine, iron, manganese, zinc, molybdenum, nickel, and chromium. 

Molybdenum, nickel, and chromium don’t have recommended nutritional values at this point. 


Mineral Lactating Cows Dry Cows Growing Calves Maximum Levels
Chromium 50 ppm
Cobalt 0.1 ppm 0.1 ppm 0.1 ppm 10.0 ppm
Copper 10.0 ppm 10.0 ppm 10.0 ppm 100.0 ppm
Iodine 0.50 ppm 0.50 ppm 0.50 ppm 50.0 ppm
Iron 50.0 ppm 50.0 ppm 50.0 ppm 1,000 ppm
Manganese 20.0 ppm 40.0 ppm 40.0 ppm 1,000 ppm
Molybdenum 5.0 ppm
Nickel 50.0 ppm
Selenium 0.10 ppm 0.10 ppm 0.10 ppm 2.0 ppm
Zinc 30.0 ppm 30.0 ppm 30.0 ppm 500.0 ppm


Additional Resources

For more information on the risks of downer cow syndrome see the Merck Vet Manual

To learn more about mineral requirements of cattle see the University Of Georgia Extension publication.

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Annemaria Duran

Hi, I’m Annemaria Duran. I moved out to the country 6 years ago, mainly so I could have more land. I love all aspects of country living. First, we got chickens, then ducks. Now we have sheep, goats, and rabbits. I'm always learning and love sharing it!

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