Cows spend up to 10 hours every day grazing, so any small change in the grass they eat can have a large impact on their overall health.
In most places, pastures are not just grass, but contain a number of other plants and weeds including dandelions, daisies, and clover. Of these common weeds, clover is the one farmers need to be most wary of.
Cows can consume clover in moderation, however too much of it can cause some serious health problems. In addition, when grass with a high clover content is turned into hay, the clover takes longer to dry out and can cause dangerous mold to form in the hay.
In this article, we’ll find out about why farmers need to be careful of clover, what happens when cows eat clover, and how to prepare hay safely to ensure clover doesn’t cause any issues.
Can Cows Eat Clover?
Cows can eat clover in moderation, but only if it is fresh and mold-free. Eating a large quantity of clover can cause digestive problems for cows, and hay which is formed from clover-rich pasture has a higher chance to become moldy.
Cows should not eat hay which contains clover, unless the farmer has prepared the hay in such a way as to ensure the clover has not had a chance to rot, otherwise the clover may create mold within the hay.
Is Clover Dangerous for Cows?
There are various types of clover which grow across the world, some of which can cause digestion problems for cows if eaten in large quantities. In particular, sweet clover, yellow clover, and white clover varieties can cause bloat in cattle, which is a potentially fatal condition.
According to specialist cattle veterinarians Evolution Farm Vets, bloat can cause problems with the cow’s breathing, prevent them from eating, prevent them from belching/burping (which is essential for cows), and may eventually lead to their death.
Clover can be dangerous for cows if it’s consumed in large quantities, or if it’s improperly treated before being included with hay or silage.
Without adequate time to dry, clover is prone to causing rot and mold which can spread throughout an entire hay bale or silo of silage without the farmer noticing.
This type of mold acts as a catalyst for the production of the harmful toxin dicoumarol, which can be fatal for cows.
Read More: What Do Cows Eat?
Can you Safely Feed Clover to Cows?
Ensure you follow laws in your local jurisdiction and ask the advice of your local vet.
Clover is usually naturally occurring in pasture lands, but may also sometimes be planted intentionally as a cover crop to improve the soil quality after grazing. (Cows can eat many different types of flora, so a more cow-friendly cover crop is another option)
To ensure your cattle don’t succumb to the dangers of clover, it’s important to take care when creating hay or silage from clover-rich pasture, and to avoid letting cows graze where clover has taken over the grass, especially where it has been intentionally planted.
Read More: Treats for Cows
Here are some ways people have used clover as a cattle feed:
1. Make Sure Clover is Dry Before Packing Hay Bales
Before creating bales of hay, it’s important to make sure any clover has had the chance to completely dry. If clover is included in the bales before it’s had a chance to dry out fully, rot and mold will take hold at the centre of tightly packed bales, where the moisture has nowhere to escape to.
This type of mold can cause serious health problems for cattle.
2. Avoid Adding Clover to Bales
Maybe easier said than done, but one possible option to avoid clover contaminating hay bales is to avoid creating bales from clover-dense areas.
Cut around clover patches and avoid creating bales from fields which have been intentionally sown with clover as a cover crop.
3. Alternate Clover with Other Feeds
If you’re feeding your cattle clover or sweet clover as a feed supplement, consider rotating their feed with a more traditional feed like corn or oats to prevent overeating.
Similarly, any cattle grazing in clover rich fields should be rotated periodically to fresh pasture to ensure they eat a wide balance of grasses and other foliage and don’t end up overindulging on clover.
This kind of intermittent feeding and pasture rotation helps reduce the risk of clover while still allowing full land use with a little planning.
Cattle may adjust slowly to feeding on clover, so it’s better to switch them around every couple of weeks to prevent them from getting used to overeating.
Dangers of Clover for Cattle
Clover is dangerous for cows in two ways:
1. Rotting Clover Contains Dicoumarol, Which Inhibits Vitamin K Production
The main danger from clover doesn’t come from the clover itself, but from the mold which occurs when wet clover is included in hay bales and allowed to rot.
Rotting clover creates a toxin called dicoumarol, which inhibits the production of vitamin K within cattle.
Vitamin K deficiency can cause fatal internal bleeding and is a problem for all mammals, including humans.
2. Clover May Cause Bloat, A Potentially Fatal Health Problem For Cattle
Some varieties of clover can induce bloating when consumed in large quantities.
Bloat is caused when an excess volume of protein is included in a cow’s forage, which leads to a buildup of gases in their rumen (stomach).
When cows eat a large volume of clover, the protein from the clover creates froth in the cow’s stomach, which prevents them from being able to belch. This creates a buildup of gas and pressure in their stomachs which can eventually lead to breathing problems and death.
To sum up, cows can eat fresh clover, but only in small quantities. Excess amounts of clover can cause bloat, which is a fata buildup of gasses in a cow’s rumen.
Aside from bloat, clover also presents a threat to cattle through the mold it creates when included with hay.
Clover which has not fully dried is often included with hay bales, and the damp clover festers in the centre of the bales where no moisture can escape.
When rotting clover creates mold in cows’ feed, it creates a chemical called dicoumarol, which is highly toxic to both cows and humans.
To ensure cattle can eat clover safely, farmers can avoid adding it to hay bales, or ensure that it’s completely dry before packing the bales. In fields which are dense with clover, farmers can rotate their cattle periodically to prevent them from overeating.
Stuart is the editor of Fauna Facts. He edits our writers’ work as well as contributing his own content. Stuart is passionate about sustainable farming and animal welfare and has written extensively on cows and geese for the site.