Abomasal Displacement

Abomasal displacement is one of the simplest examples of the disruption of the ruminal buffer system or CO2 holdup.

I reviewed the pathogenesis of this disease in Laporte-Uribe (2016), but thanks to our latest experiment, I can update this concept (Laporte-Uribe, 2023).

It is still not clear what leads to CO2 holdup: whether the diets cause the disruption of the buffering system directly (Fay et al., 1980), or this is a response of ruminal bacteria to a rich carbohydrate diet which produces a high dCO2 environment. for instance, High dCO2 promotes the production of LPS, which is know to increase the viscosity of the rumen fluid (Cheng et al., 1976; Cheng et al, 1979).

Maybe it is a combination of both, during SARA, CO2 holdup was independent of feed intake, see Laporte-Uribe 2013. I observed CO2 holdup and SARA when cattle’ feed intake was already depressed. i.e., those spikes in dCO2 concentrations for extended postprandial periods with the RDS diet.

What is certain is that when CO2 Holdup is established, dCO2 and HCO3- accumulates, the solution becomes non-ideal, and CO2 gas cannot be easily fizzled out of the rumen fluid (Laporte-Uribe, 2013).

As the ruminal liquor overcharged with dCO2 makes its way into the abomasum. The enzymatic digestion of the matrix that retained liquid dCO2 is broken and the CO2 gas is released. The fast release of CO2 gas produces stable foam and displacement, typical signs of this disease.

Stable foam and CO2 holdup are part of the same phenomena: CO2 holdup occurs within the liquids, whereas stable foam occurs on the top of the fluid.

By monitoring dCO2 concentrations, we can observe CO2 holdup being formed, thus proactively change feeding conditions and “prevent” clinical cases of abomasal displacement and many other nutritional diseases.