10 May 2002

Is early grass cause of rise in digestive ills?

By Jonathan Long

UNUSUALLY high energy grass, together with changes to dairy cow management and feeding, could be behind a rise in the number of cases of a digestive problem.

Independent vet consultant Tony Andrews says the occurrence of displaced abomasums, commonly seen in the winter months, is more frequent this spring.

The condition, which is seen in the first few days or weeks after calving, results in the abomasum becoming trapped under the rumen and reticulum. Symptoms include a variable appetite, swelling of the left abdomen and reduced dung production.

"Significant increases in the volume of feed and its protein content will lead to mild acidosis. This reduces activity in the rumen and causes the walls of the abomasum to become flabby.

"This lack of structure in the abomasum can lead to it being free to move more easily," says Mr Andrews.

A further factor in the lowering of rigidity in the abomasum could well be a shortage of long fibre in the diet of cows precalving.

"Spring calving cows may be more susceptible this year, as fine weather has allowed cows to be turned out onto early grass which is often high in energy and easily digestible, but lacking in fibre."

He suggests counteracting this by buffer feeding straw in the collecting yard before and after milking.

"Long fibre stimulates the rumen wall causing it to have good movements and activity. This in turn increases saliva production helping to reduce the chances of acidosis."

To lower the chances of displaced abomasums he advises adding 0.5-1kg of hay or straw to diets, so long as the fibre is longer than 4-5cm (1.5-2in). &#42

Early grass can lack fibre, increasing risks of displaced abomasums in fresh calvers.

&#8226 More common this spring.

&#8226 Add fibre to diet.