7 ways to lower the risk of ‘rumen drinking’

How quickly calves consume milk and at what height they drink could be contributing to calf mortality on dairy farms and calf-rearing enterprises, according to Scottish data.

Rumen drinking is where milk is directed to the rumen and reticulum instead of the abomasum.

This was identified as the second most common contributory factor to calf mortality during routine surveillance testing of 614 pre-weaned dairy and dairy beef calves.

It was found in 101 calves.

Of the 1,017 diagnoses made, 247 were nutritional, including conditions such as acidosis and bloat, as well as rumen drinking. (Pneumonia accounted for 216 diagnoses.)

See also: Calf monitoring and health plans key to future performance

In milk-fed calves, the oesophageal groove closes when the calf suckles. Rumen drinking occurs when this reflex fails (see “Rumen drinking facts”).

Chronically affected calves have a poor chance of recovery, so prevention is crucial.

Colin Mason, veterinary investigation officer for Scotland’s Rural College (SRUC) Veterinary Services, collected the data with colleague Katrina Henderson.

Although the sample set was from 2014-18, he suspects the pattern is unlikely to have changed.

In fact, he believes calf mortality linked to nutrition – and specifically rumen drinking – is on the rise.

Vet Ali Haggerty of Stewartry Vet Centre says she commonly sees this issue on farm. “It’s a routine diagnosis, or it’s on my radar whenever I deal with calves,” she explains.

“I would think of it as a sort of iceberg. You might see one or two with the classic clinical signs, but there might be others in the group that are subclinical.”

A group of affected calves will commonly present with a scale of clinical signs (see “Signs of rumen drinking” below).

Subclinically affected animals are likely to have changes in the gut.

Ali says rumen drinking can create a “downward spiral”, leading to issues like scours and bloat. Concurrent disease also raises the risk of rumen drinking, as does being immunocompromised.

Colin explains that acid build-up in the rumen from milk overflow leads to a “vicious cycle”, causing the oesophageal groove to fail more frequently.

This means more milk goes into the rumen, creating more acid.

“Every farm will be different, but in my view, it comes down to the speed calves are fed,” he says.

“If they drink really quickly, you’re more likely to get milk spilling into the rumen.”

To lower the risk, Ali, Colin, and Lorna MacPherson, dairy consultant for SAC Consulting, suggest the following:

1. Opt for teat feeding

Calves that died from rumen drinking were 4.3 times more likely to have been fed from an open bucket than a teat, compared with calves where there was no nutritional component to their death, according to SRUC.

“I wouldn’t use buckets at all. I think they drink too quickly through them,” says Colin, emphasising the benefits of teat feeding instead.

Teats should be checked daily, and any with cracks or wide holes replaced. Lorna advises against widening holes to get calves to drink faster.

2. Think about feeding height

Drinking height has been found to impact rumen drinking.

Ideally, the calf drinking position should be “as natural as possible”, as if suckling the dam.

This is also why bucket feeding is not advisable. Lorna suggests the teat should be at nose height.

3. Consider feeding volume

If calves are fed low quantities of milk, they are more likely to gorge themselves and drink quickly because they are hungry.

High volumes of about 8 litres a day can also increase risk and are more suited to feeding little and often, through a teat or automatically, to reduce rapid drinking.

When calves are being fed manually via a teat, Colin suggests slowing down consumption.

This could mean letting the calf drink 2 litres first and then topping up with another 2 litres after it has finished.

4. Avoid repeated tubing

Calves that are repeatedly tubed are at risk of rumen drinking.

Colin stresses this does not mean tubing is bad and can be a useful way of delivering colostrum immediately after birth.

However, repeated tubing to deliver milk on “time-poor” farms should be avoided.

5. Minimise competition at the feeder

Large group size or anything that creates stress or competition at the feeder will increase risk of rapid drinking.

Subordinate calves being bullied by dominant calves are more likely to guzzle their milk.

6. Consistency is everything

“Make sure your feeding management is consistent,” Lorna says.

This should apply to milk mixing, timing and temperature.

She adds: “One of the things that can affect oesophageal groove closure is taste, or just something out of the ordinary or not routine.”

7. Pay close attention to colostrum

Immunocompromised calves are at higher risk of rumen drinking, so delivering high-quality colostrum is one way to help protect them from disease.

Dirty colostrum will also increase the chance of calves entering the downward spiral associated with rumen drinking.

For example, if calves are stomach tubed, colostrum goes into the rumen and then flows out.

However, problems arise if the colostrum is full of bugs.

“You’re going to set up that fermentation-inflammation cycle,” Ali explains.

This means calves might not be feeling well when they start feeding on a teat, leading to reduced suckle reflex and increased chance of rumen drinking.

Treatment

Recovery is unlikely in chronic cases, which means prompt treatment is essential.

In acute cases, Ali advises:

• Tubing with electrolytes containing bicarbonate of soda
• Introducing milk feeding little and often, via a teat. This may mean starting with feeds of 0.5 litres, three to four times a day. Be “calf-led” as to how quickly rates are increased
• Offer the calf a finger to stimulate the sucking reflex before putting it on the teat
• Speak to a vet about using anti-inflammatories on a case-by-case basis, as stomach ulceration can be a side effect and may exacerbate the problem.