3 August 2001

Restrictions cause digestive problems

DIGESTIVE problems in cattle, particularly caused by nitrate ingestion, are being reported in herds unable to move to fresh paddocks due to movement restrictions, vets warn.

Cumbria-based vet Matt Colston says cases of indigestion are increasing in cattle grazing either long/stemmy or short/soil contaminated grass. "These animals are just not taking in enough fresh grass and when other graz-ing is unavailable they must be buffer fed."

Cattle are also at risk from nitrate poisoning when they are kept in fields that are receiving fertiliser, adds Mr Colston.

Nitrates to nitrites

Nitrates turn into nitrites in the animals body which cause indigestion and scouring, but in larger quantities – handfuls of fertiliser – will stop blood taking up oxygen causing blood to turn a chocolate colour, explains independent vet Tony Andrews. Because of oxygen deprivation, an animal can die within half an hour of eating large quantities of fertiliser, he adds.

Although Mr Colston advises against spreading fertilisers while cattle are in the field, in extreme cases when there is no other grazing available, the smallest amount possible should be spread.

The field could also be divided into sections with electric fencing so fertilisers can be applied in stages away from animals. "However, this will put grazing under more pressure and animals may suffer from lack of food so buffer feeding should be provided until the fertiliser has been absorbed by the soil." &#42