June 29, 2009

Displaced abomasums (DA) are still causing issues on many dairy farms in UK and was up 23 percent from January to April this year, figures from the National Animal Disease information show.

 

Abomasum is the fourth and final stomach compartment in ruminants which secrets rennetes, an ingredient used in manufacturing cheese.

 

Veterinarian John Burnside, Torbridge vet hospital, Bideford, Devon said the number of DA's should ease off this time of year. Das are usually associated with early turnout on spring grass or as a result of poor quality and consistency of forage fed in winter.

 

However, an increase in June and a 46 percent hike of treated cows from January to May this year compared with 2008 may be due to the fact that farmers are still relying on old forage for buffer feeding.

 

Older, poorer quality forages will have a negative impact on feed intakes, reducing rumen fill and predisposing animals to displaced abomasums, he said.

 

Fresh calvers are particularly vulnerable to DAs, says senior technical specialist Rob Mintern.

 

If a cow has not maintained sufficient dry matter intakes before calving, and thus the rumen is not large enough after calving, there is a chance for the abomasum to become displaced.

 

It ultimately comes down to transition cow management, he says, and dry cows will maximise dry matter intakes, so the rumen will naturally fill the space where the calf has been after calving.

 

Mintern also advised that two weeks prior to calving, give cows access to the same forage they'll get post calving. If they're going on to corn, he said, include the grain in the ration and ensure this is balanced with enough fibre.

 

Ideally, dry cows should be split into a far-off calving and close-to calving group to allow close management.

 

Kingshay trials have shown it is possible for cows in the close-to calving group to consume 14kg DM a day. Aim for cows to eat more than 13kg DM a day of a fibrous, palatable ration; mixing straw into a good quality ration can maximise intakes.

 

Body condition should also be closely monitored. Fat cows will have reduced intakes post-calving. Condition score at 200 days so you can manage individual cow condition accordingly.

 

Just after calving, the chance of DAs can be reduced by guaranteeing good access to water and feed.

 

Even when the rumen is small, problems can be reduced by getting a cow to drink and eat as soon as possible after calving, experts said.

 

A cow loses about 50 litres of fluid at calving, which she must replace before she eats.

 

If a cow has to walk more than 3 metres away from her calf, experts believe she won't do it, so it is essential water is close by. And this becomes even more of an issue in hot weather.

 

Ideally, keep a fresh cow group for a week after calving. This will allow you to closely monitor feed and water intakes.

 

Grazed grass can also pose a problem post-calving, says Keenan nutritionist, Mark Vos. Leafy, low-fibre grass will inherently reduce cudding, potentially leading to DAs, he said.

 

It is essential to supply the correct amount and consistency of feed to maximise chewing and rumen function alongside grazed grass.

 

Grass cover must also be assessed to monitor dry matter intakes. "Dry matter will vary from field to field, so assess grass supply regularly and adjust rations accordingly."