Treating Bloat during Grazing Season in 2021

Treating Bloat during Grazing Season in 2021

Rumen Bloat in Dairy Cows

At Terra NutriTECH, our team know the importance of keeping your Dairy Herd healthy. Year on year, we talk to farmers about the animal health issues that are affecting their farms. At this time of year, a key concern for farmers is ‘Bloat’. As the grass starts to grow there is one challenge along with grass tetany farmers now need to be on the watch for. That is ruminal bloat during the grazing season. At Terra NutriTECH, we aim to manage farming systems ensuring that farmers promote prevention where possible.

What exactly is Rumen Bloat in Dairy Cows?

The rumen is a magnificent organ. This large fermentation bath is what drives production. Taking inedible cellulose and converting it to digestible fatty acids. It is extraordinary what our cows and sheep do by turning the largest biomass in the world (cellulose) into protein for human consumption.

We must remember the key to successful ruminant farming systems is good rumen health. It is the billions of microbes in this large stomach that are making the magic happen. When rumen health becomes unbalanced we can also slow down this efficiency and even have severe disruptions like bloat.

Bloat is where the excess gas (methane and CO2) produced in the rumen can affect normal function. It can occur quite rapidly meaning that death can ensue also quickly. It causes huge pressure in the chest of ruminants and often leads to cardiogenic shock.

So we must be mindful of the risks and then aim to limit them.

There are two types of Bloat – Primary & Secondary

  • Primary which is where excess gas is produced in the rumen. This is by far the most common type of bloat. We typically see this at the moment in the form of Frothy bloat at pasture.
  • The other type of secondary bloat we see is where something obstructs the expulsion of gas in a normal functioning rumen. These cases will respond well when spotted to relieving the gas by stomach tubing. They may swell up quickly again meaning that the cause of the obstruction is still there. These cases will often need a permanent trocar or fistula if bloating continues. Examples of these can be foreign body obstructions or abscesses in the esophagus.

Understanding Primary Tympany

Frothy bloat (primary tympany) results when fermentation gases are trapped in a stable, persistent foam which is not readily eructated. This creates a foam in the gas layer which is not easily eructated (belched). These animals will start to swell up quickly often on the left-hand side (where the rumen sits). They can often go down and bloat up quite quickly.

These cases, unfortunately, are often found dead.

dairy cows, bloat oil

Treating cows with symptoms of Bloat

These are emergencies and require urgent attention. Normal tubing may not expel this foam very well. These cases may require trocars or ruminal fistulas placed by your vet.

Time is against us here, so we need something that will reduce the formation of this foam. We can use detergents or anti-foaming agents. When spotted first they should be walked back to the yard slowly.

Walking can take the pressure off for a short period until treatment is administered. Animals down may need emergency intervention rapidly to relieve the gas.

Oral treatments with oils or detergents will have success along with methods to relieve the gas.

Any animals found dead at pasture consider bloat, tetany and clostridial diseases as differentials.

A very good mineral system. No dusting silage

with minerals or bolus to cows.

Farmer response to using Terra NutriTECH

Why does Bloat occur in Spring?

Lush pastures being low in fibre and high in soluble protein may increase the risk. Clovers, in particular, create extra risk. Also, spring grass can be high in sugars and water content all meaning these bugs are working harder and producing a lot of gas.

bloat oil minerals

This may also mean less saliva production which can act as a buffer in the rumen,

These soluble proteins can rise to the top of the rumen becoming insoluble and causing this froth to develop.

Indoors we see bloat in finishing cattle where we see a big increase in concentrates and low fiber in the diet. This can occur particularly where grains are finely ground.

Our Veterinary Consultant Tommy the Vet spoke to two farmers last week who both suffered unusual and bad cases of bloat. The only thing that both had in common was that they turned out cattle to pasture that had just recently been fertilized. Now nitrogen poisoning is also a differential but the cases presented with bloat.

Possibly the recent fertilizer application could have increased the NPN in the rumen leading to more gas and insoluble proteins being formed.

So it is time to be vigilant and great care should be taken when putting stock into new lush pastures with clover. The use of strip wires to slowly introduce them might be the wise choice during the risk period.

If you get a suspect case of bloat recheck grazing strategies and reduce the risks.

Gives assurance that cows are getting the
correct minerals every day.

Farmer Response to using Terra NutriTECH

Prevention – Bloat Oil in the Water

Some people will feed bloat oil in water during risk periods, particularly with at-risk swards like clover. The automated mineral dosing system offered by Terra NutriTECH ensures that Bloat Oil is administered to your herd efficiently.



  • Aids in the prevention of bloat in stock, who feed on lush grass or high clover content.
  • Helps with herd health and milk yield.


  • Blend of ethoxylated Castor Oil.

Sizes & Dosing Rate

  • Available in 20kg and 200kg.
  • Dosing ratio 40mls per head per day.
Bloat oil

Our experience suggests that prevention beats cure all day long. When we manage farming systems, we can manage the risks by planning ahead.

Severe cases of bloat can lead to death, so – therefore – prevention is important. Bloat can be prevented. The addition of our Terra Nutritech bloat oil into the drinking water and/or on top of the feed is an effective and easy way to prevent bloat in the herd, as it acts as an anti-bloating agent. When administering bloat oil, it is important that it is given accurately and uniformly across the herd in all weather conditions

Talk with our Team

Please call Ronan on 087 7086714  to find out about using an automated mineral dosing system. There are many health benefits for your cattle. Continue planning for the year ahead.

We also recommend the services of our sister company Terra Services who specialise in farming-related services and products such as water troughs and piping accessories.