Immature crops kill stock

Press, 31 March 1989, Page 11

Immature crops kill stock

By

HEATHER CHALMERS

Farmers are being warned of the possible danger of feeding stock immature rape crops, after nitrate poisoning killed 250 ewes on a farm at Killinchy, near Leeston. The Darfield and Oxford areas have been particularly affected by the poisoning, with many farmers reporting the deaths of small numbers of stock.

A Killinchy farmer, Mr Howard Lemon, said he had been

feeding 1500 breeding ewes alternatively barley stubble and a mixture of rape and oats.

On the first day the stock were fed the rape crop they appeared healthy. However, on the second day they “dropped like flies,” Mr Lemon said. “The plants take up nitrate from the soil in preparation for growth and if stock graze it at that time it’s toxic to them,” a veterinarian at the Malvern Farmers’ Veterinarian Club in Darfield, Mr Alan Pearson, said.

The toxic level in the plants could rise and fall very quickly and the crop was only definitely safe for stock later in the season when it was mature. However, because of the shortage of feed, farmers were putting stock on to the rape crops early. Turnips and green feed oats could also be affected. “I don’t want farmers to avoid feeding crops when they have no other feed, but crops should be tested first and managed in a way that will put animals at less risk,” he said.

“They started dying about three to four hours after I put them on. Most of them were dead within five hours,” he said. In total, 250 ewes died in the flock, which was not insured.

Mr Pearson said nitrate poisoning occurred every year, but this year’s problem was earlier and more severe than normal because of the drought. The problem occurred in immature rape crops of which the growth pattern was variable because of the long dry spells.