Often referred to as a ‘twist’, a displaced abomasum (DA) is an expensive event on the farm.  Associated costs include:

1. Loss of milk production – 700-1200lb less milk produced in the lactation
2. Veterinary costs – surgery, medicine
3. Replacement costs – due to increased risk of culling or death

What causes a DA?

DAs is a multifactorial disorder, at times with a complex web of contributing factors – some of which I have listed below. I find it helps to think about risk factors and associated management practices within the following formula:

↑Space in Abdomen + ↓ Motility & ↑ Gas in Abomasum = ↑ Risk of DA

Risk factors associated with an increase in abdominal space 

• Deeper barrel conformation of modern cows

• Calving (i.e. loss of calf weight, placenta, and fluids)
• Reduced dry matter intake and rumen fill
  • Calving time (i.e. natural drop in dry matter intake)
  • Concurrent disease-causing inappetence, e.g. metritis, mastitis, pneumonia…
  • Ration issue, e.g. wet silage, palatability, high energy/low fibre, mixing errors
  • Bunk issue, e.g. competition, infrequent push-ups, limit feeding
  • Cow comfort, e.g. stall design, ventilation, heat abatement
  • Social stress, e.g. pen movements in the transition period

Risk factors associated with low abomasum motility and excessive gas accumulation

• Hypocalcemia (i.e. calcium required for contraction of all muscle types), e.g. dry cow nutrition, parity (lactation #), genetic predisposition
• High rumen volatile fatty acids (VFAs), e.g. high energy/low fiber ration, sorting
• Ketosis (low glucose and insulin lead to reduced abomasum motility), e.g. over-conditioned cows at freshening (body condition score >4), dry cow nutrition

How do I reduce the risk of a DA in my herd? 

It is not realistic to expect the elimination of DAs, but rather a target of <4% annually is achievable. Review your farm protocols and engage your vet and nutritionist farm advisors on the following subjects:

• Monitoring, preventing and treating fresh cow illnesses

• Nutrition management

• • • Ration formulation for optimal dry matter intake and suitable fibre/energy levels
    • Critical control points for delivery of a consistent and appropriately processed ration

• Regular dry matter testing

• • Ensuring feed changes are gradual and are preceded by forage testing and ration formulation

Facility and cow comfort strengths and opportunities – e.g. stall design, social groupings, bunk competition

– Dr. Shannon Walsh

If you have any questions on these or other topics, please do not hesitate to contact one of our Veterinarians.