Winter feed crops are critical at Craigmore

GERALD PIDDOCK

Winter feed crops are critical for reaching spring production targets for Central Canterbury livestock farmers. Their establishment and management was the focus of a Beef + Lamb South Canterbury Monitor Farm field day at Craigmore Station. Gerald Piddock was there.

CRAIGMORE STATION, the 4000ha sheep, cattle and deer farm located in the foothills behind Cave, has been owned by the Elworthy family since 1864.

It is managed by Dan Chaffey and agricultural manager Andrew Fraser.

The station runs 6000 romney sheep. It breeds its own replacements and produces meat and wool.

It also runs breeding cows and rears the replacements and breeding hinds for venison production. Craigmore also receives 10 per cent of its income through pheasant shooting. The staff release about 2500 pheasants. About 60 per cent of them fall to the gun each year.

Craigmore's fodder beet, kale and italian ryegrass crops are fed to their livestock over winter to meet production targets.

The station's 10.4ha crop of brigadier fodder beet was sown on October 14 at a rate of 80,000 seeds per hectare and has an expected yield of 18 to 24 tonnes per hectare.

It is used to meet the 150 grams per day production targets for the station's elk-crossed mixed sex weaner deer for the spring market.

It was the third week the deer had been on the crop and the station's management team said favourable weather conditions and feeding out a high protein and fibre rich supplement were critical in hitting that growth rate target.

"The more we strike into that good spring market, the better. They are 72kg coming on here and we have to put 30kg on them," Andrew Fraser says.

The weaners are currently getting baleage fed out and will be fed silage and barley over winter, he says.

Deer were a good match for fodder beet because they were self-regulated eaters. Unlike cattle, they did not gorge themselves and this limited the risk of acidosis, an illness caused by an excessive intake of feeds rich in starch and carbohydrates. It causes abnormal acid fermentation in the animal's rumen and can kill livestock if untreated.

Allowing two weeks for the rumen to adjust to a new diet helped prevent this illness, retired Lincoln University plant scientist Warwick Scott told farmers at the field day.

"The young stock are on a bulb crop. They haven't been on this before and it's a real change."

He urged the importance of knowing accurately how much dry matter yield the crop had. Erratic plant spacing in fodder beet crops could skew crop yield estimates.

This was caused by the beet's seed, which was a cluster that had several seeds in it. This cluster could be chopped up but that ran the risk of double "runt" bulbs forming.

Similar feed principles should be used on brassica crops such as kale, he said.

"Start your animals on it slowly and feed that fibre. You have got to slow down that passage to the rumen."

Craigmore has 19.4ha of sovereign and gruner kale used for wintering bulls.

Their 26.7ha of rape and 22.7ha of italian ryegrass crops were fed to their 2000 inlamb hoggets. For sheep grazing on that crop 80-grams-a-day weight gain was targeted.

Although low yielding, the big advantage using italian ryegrass was its re-growth after grazing. That occurred as long as the crop was back-fenced. It was a high quality crop and also produced excellent silage for young stock, Warwick said.

He also suggested supplementing the hoggets diet with feeding out fibre with the rape.

Growing a feed crop was like running a marathon. Failing to achieve those liveweight gains once the livestock was on the crop meant not finishing the marathon, PGG Wrightson ruminant nutritionist Charlotte Westwood said.

The key driver for stock doing well on winter feed crops was knowing the total kilograms of dry matter feed available.

"Dry matter consumed is 99 per cent of the focus of nutrition."

Crop utilisation also impacted on that feed availably. No farmer would ever use 100 per cent of their crop and they needed to factor crop wastage into their feed budget, she said.

She urged getting crop samples tested for their dry matter percentage.

Winter feed crops should be a low proportion of animals' diet during their first few weeks on the crop.

Most of the nutritional and health challenges among livestock occurred during their first two to three weeks on a winter crop. To minimise that the crop should provide a low proportion of the animals' diet during that initial period, she said.

"The crop, even though it's green, is the most different type of feed that you can possibly think of compared to grass and it will take up to three weeks for the rumen to transition the types of microbes from grass onto a crop-predominant diet."

Putting the stock onto those crops with a full stomach also reduced the risk of acidosis and nitrate poisoning, she said.

As a general rule, fibre was required as a supplement for livestock on winter feed crops. Cattle and deer required at least 30 per cent of their diet to be fibre when eating high quality winter forage crops, while lambs needed 10 per cent, she said.