Origin of abomasum gas in the cows with displaced abomasum.

Abstract

The gas composition of the rumen and the abomasum were investigated in 71 cows including 25 cows with displaced abomasum. The ratio of methane (CH4) to CO2 in the abomasum gas was higher than that in the rumen. In the incubated mixtures of fresh rumen fluid, CH4 was detected at a high concentration, while a small amount of CO2 and CH4 was found in incubated mixtures of fresh abomasum fluids. Hence, it was suggested that the gas in the abomasum originated not from the abomasum itself but from the rumen. In cows fed with mixed roughages and concentrates, the rumen CO2:CH4 ratio was higher compared with cows fed with roughages alone. Marked changes in rumen gas composition were presumed to be associated with changes in abomasum gas composition. Consequently, it is possible that feeding a large quantity of concentrates may increase the flow rate of the ingesta through the forestomach, so that the return rate of gas separated from the ingesta in the abomasum to the forestomach may also increase. Therefore, the frequent accumulation of a large amount of gas with concomitant changes in the total volatile fatty acid (VFA) concentration in the abomasum caused abomasal atony and subsequently displaced abomasum.

Hematological, biochemical and ruminant parameters for diagnosis of left displacement of the abomasum in dairy cows from Southern Brazil

“…Gas produced by abnormal microbial fermentation distends the abomasum and causes the displacement. Feeding with high levels of concentrate results in reduction of ruminant motility, and increases the accumulation of abomasal gas (Sarashina et al, 1991).…”

Metabolic indicators and risk factors of left displaced abomasum in dairy cattle

“…The prerequisite for DA is abomasal atony due to the accumulation of gas and fluid in the abomasum Michel et al 2003, Wittek et al 2008, Buehler et al 2008, Doll et al 2009. Displaced abomasa usually contain more methane (up to 70%) which is comparable to the rumen (Sarashina et al 1990, Doll et al 2009.…”

Epidemiological and Diagnostic Studies on Subacute Ruminal Acidosis in Dairy Cows

“…Clinical signs of SARA include decreased dry matter intake (DMI), laminitis, rumenitis, liver abscesses, and pulmonary bacterial emboli (Nordlund and Garret, 1994;Nordlund et al 1995;Kleen et al, 2003). Abomasal displacement (Sarashina et al, 1990), mastitis, metritis (Enemark et al, 2002) and low fertility (Britt, 1995) were also recorded. In clinical practice, definite diagnosis of SARA is only established by determining the pH of rumen fluid either at a specific time-point after feeding (collected by stomach tubing or more credibly by rumenocentesis) or continuously (using electronic rumen boluses) (Duffield et al, 2004).…”