The Cows had a Breakout on Fodder Beet – What do I do??

In early June, we see many cases of acidosis on fodder beet, because of either breakouts or overallocation.

Often the first clinical signs of acidosis are not seen until 10-12 hours after the breakout and new cases may continue to appear for up to 24 hours. This is because rumen fermentation and the systemic effects of the rumen acid load on the cow are progressive.

Early clinical signs may start with a cow looking wobbly, grinding her teeth, a distended gut and a lack of interest in food (sometimes you will also see long strings of mucous from the vagina). Being proactive before they get to this stage serves a far better outcome.

The most important thing to do when there is a suspected overallocation or breakout is to act quickly. Get the whole herd off the crop immediately, provide them with as much long fibre as possible – e.g. hay, straw or bailage and/or long rank grass. This will encourage cudding and the circulation of pH buffering saliva in the rumen. This will slow down the rate of fermentation and help prevent the rumen moving into a pH free-fall.

Fine-chop silage, will not be as effective as the particle lengths are too short and the pH is lower (we want to lift rumen pH). Dust the baleage and/or pasture heavily with limeflour – work on 300-400g/cow. This will provide calcium to prevent secondary milk fever and will also help buffer the rumen.

If cows are found already down (e.g. the breakout occurred the night before), triage them by giving IV calcium (use Calpro375).

Providing additional phosphate in these cases is of zero value. Less severely affected cows, if they just have a secondary hypocalcaemia, will get up immediately, move off and eat.

Cows which are unresponsive to calcium treatment, are depressed, have a distended abdomen, sunken eyes and grinding teeth have a poor prognosis. Cows which are still modestly bright but cannot stand after IV calcium (or those that are standing but look sickly), should get stomach tubed with Selekt Antacid mix (just mix with 5L of water), be given a 3-day course of high penicillin (to treat rumen ulcers) and a dose of Metacam (to reduce toxaemic effects).

Moderate to severely affected animals are best to spend the remainder of winter on grass, while the rest of the herd can be returned to the crop the next day at 2/3rds of the previous allocation before rebuilding them.