Beef farmers warned about straw impaction after cow deaths

What causes straw impaction?

  • If you feed high levels of straw you must supplement it with a source of protein or urea.
  • If you don’t, rumen bugs cannot digest the straw. The straw therefore passes into the abomasum undigested and forms a blockage.

Symptoms of straw impaction

  • Low appetites
  • Very solid dung

Farmers are being warned about the risks associated with feeding straw-based diets after post-mortem data revealed there’s been a spike in the number of suckler cows dying from straw impaction.

Straw impaction occurs when cows are fed rations containing mainly straw, without sufficient protein supplementation and straw then becomes blocked in the omasum/abomasum.

Vet Ben Strugnall, who operates the carcass-based diagnostic service Farm Post Mortems at J Warren in Hamsterley, County Durham, said four suckler cows had died from straw impaction in the past two weeks.

See also: Step-by-step guide to assessing rumen function in beef cattle

He said the animals were housed and being fed a high straw diet supplemented with molasses with urea, but in this case it wasn’t enough.

WARNING: GRAPHIC IMAGE BELOW

He said many farmers countrywide could now be being forced to incorporate high levels of straw into diets to make up for forage deficits.

With turnout still one month away for most, he suggested those farmers feeding straw should ensure they are supplementing it appropriately.

Abomasum and rumen

The Abomasum is on the right and should be one-third the size of the rumen, which is on the left. In this case it is bigger because of the accumulated straw. Poorly-digested straw pass out of the rumen if the rumen bugs are not provided with enough protein (RDP) to digest the straw, and can become impacted in the abomasum or omasum. Abomasal contents should normally be liquid.

Straw-based rations can be successful, but they rely on the ration being supplemented to provide sufficient protein and fermentable energy to feed the rumen bugs so they can break fibre down.  

Tips for successful straw-based diets

  • Ensure the overall diet contains at least 9% crude protein in the diet dry matter
  • Where feeding other forages, analyse these to ensure the complete diet meets overall protein requirements
  • Include a supplementary source of protein if required – for example, rapeseed meal, distillers grains, or peas/beans
  • Make sure straw is clean and palatable
  • A straw-based diet is very dry, so ensure a plentiful supply of clean water
  • Ensure all cows have good access to the supplement and the straw
  • Mineral supplementation is important and needs to be suitable for suckler cow straw diets with good levels of trace elements and vitamins
  • As calving approaches, consider adding silage with the straw to ensure cows have a smooth transition if they are on a silage-based diet post-calving

Source: Mary Vickers, senior beef scientist at AHDB

For more information please refer to the BRP manual: Feeding suckler cows and calves for Better Returns.