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Mole Valley Farmers warns of lower rumen function this winter

26 November 2020

Low fibre grass silage, high starch maize and greater use of co-products in rations have pushed vets and nutritionists to issue a warning surrounding rumen function this winter.

Mole Valley Farmers’ Richard Keel says "fizzy," low fibre diets are creating the perfect recipe for rumen upsets. As such, he is urging farmers to assess diets and put preventative measures in place to "recharge the rumen."

He explains: “We have noticed that there are some nutritional shortfalls in this season’s dairy cow diets - especially in relation to fibre nutrition. Fibre is essential for the rumen to work efficiently. Left unaddressed, this could result in the rumen pH dropping below the target pH of 6-6.3, leading to
Sub Acute Ruminal Acidosis (SARA).”


SARA can cause the fibre digesting bacteria in the rumen to die and lactic acid producing bacteria to thrive, resulting in a viscous cycle of acid production. This will lead to a number of issues, says vet, Andy Adler of Molecare Vets who advises farmers to carefully assess cow behaviour for signs of problems.

“One of the most common clinical signs of SARA are cud balls,” he says. “Other than that, you get very variable and often subtle signs. The common ones are cows going off their milk for a short period, a drop in butterfats, swishing of tails and dirty cows. If the faeces is very loose or there’s grains in there, that’s a sign SARA could be an issue and we may need to think about how we manage that.”

Richard says the first step should be to assess the diet and address any issues with ration balance. In high starch, low fibre rations, this could mean adding chopped straw.


“Straw may be expensive this season, but it will have a big impact on rumen function,” he says. “You may also want to introduce a live yeast to support rumen function and digest the additional fibre.”

A quality yeast, such as X1-LIVETM Yeast, helps create an anaerobic rumen environment in which fibre digesting bacteria can thrive. This assists rumen turnover, increases intakes, helps get more milk from the same diet and can boost milk butterfat production.

“If long strands of fibre are being seen in the dung, this could be a sign that feeding a yeast could be beneficial,” Richard adds.

In diets with high levels of fast fermenting products such as co-products and cereals — and where it’s difficult to balance with more fibre - adding a rumen conditioner, such as Combi-BUFTM may be beneficial. Rumen conditioners work by creating a sustained, consistent rumen pH. Speak to a nutritionist for advice on which product to use on your farm.

Richard adds: “This is ultimately about producing a stable rumen. If you limit fluctuations in rumen pH, you will get better fibre digestion, microbial growth, feed conversion efficiency and milk output.”


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