More resistant

19 March 1999

Fat-burning ration may boost heifer carcasses

The latest beef research

was on show at last weeks

SAC Bush Estate open day.

Allan Wright reports

HEIFERS will continue to be barred from beef special premium payments despite new flexibility in the system announced in Brussels as part of CAP reforms.

It means that finishers will continue to use more intensive systems for heifers to reduce feed costs. SAC has developed a new ration to stop intensively fed heifers producing lightweight, overfat carcasses.

"The trend to intensive heifer finishing has resulted in a big increase in the number of animals finishing below 250kg carcass weight and at 4H or fatter. These animals are difficult to market and are discounted by as much as 25p/kg," said SAC beef expert Basil Lowman during an open day at SACs Easter Howgate farm, Edinburgh.

Researchers have countered the problem with a fat-burning diet based on beet pulp, similar in nutritive content to spring grass. In a trial, one group was fed silage plus 4.7kg/day of urea treated wheat, while the others were on the fat burning diet fed ad lib.

The special diet resulted in heavier carcasses and lower cost/kg. That group also finished earlier and with better killing out percentages and much improved grades. He said that the result was an extra income of £33/head.

"It is still difficult to know how much of the benefit was due to the ration and how much was simply a response to higher growth rates. We are now comparing the ration against a control group on a standard barley beef diet. That should give us similar growth rates and we can then have a better idea of whether or not the fat-burning ration is giving improved carcass returns," said Dr Lowman.

Grainbeet diet shows promise

BEEF cattle feeding trials at SACs Bush Estate have shown up interesting initial results, but are yet to be completed.

Cattle fed on grainbeet – draff ensiled with sugar beet pulp – are performing well. The animals not only had the best weight gain -1.48kg/day – but were clearly thriving.

"Where draff is locally available from distilleries at around £10/t, grainbeet is a wonderful feed with 35% protein in the dry matter," said SACs Mitch Lewis.

In another trial allowing animals to choose the level of protein in their diet with free access to draff or urea licks, Dr Lewis has found that in both cases their protein intake level, at around 13% of dry matter in the diet, is lower than the 15% recommended by SAC.

"It may change as the animals mature but we have been a little surprised by the early results," he said.

Mid-stage results from a trial comparing ammonia treated whole wheat with a conventional barley mix ration show animals on the wheat feed lagging behind during the early stages. Liveweight gains in the first 11 weeks of the trial were 0.9kg/day and 1.47kg/day, respectively.

"Intakes and performance for the treated wheat group are improving but they will never catch up," said Dr Lewis.

Belly clipping made easier

BELLY clipping cattle before slaughter may be no more than a cosmetic exercise but it is perceived as giving the public control against E coli infection and, as such, should continue, according to SACs Basil Lowman.

He has developed a device to prevent animals forward kicking when held for clipping in a conventional cattle crush.

"It is a simple bar which goes in front of the back legs after the animal has been properly held forward with the rump bar," he explained during last Thursdays open day.

"I think a farmer with a welder could knock this up for about £50 and Im hoping that individual crate manufacturers will be able to make the modification for about £100," said Dr Lowman.

The device is not a guarantee of safety during a dangerous job and he advised being aware of apparently docile animals. "The wild one is easily recognised and great care is taken. It is the docile one which suddenly lashes out that can cause problems during clipping," he said.

But there is no excuse for presenting dirty cattle at an abattoir or market. "This should be penalised and every effort must be made to demonstrate to the public that farmers and the meat trade are doing all that is possible to make sure meat is delivered in a safe and hygienic way," said Dr Lowman.

Taste for chips

OPEN air corrals deep bedded with large wood chips are being advocated as a cheap and environmentally friendly way of overwintering beef cattle.

The chips are currently being tested against conventional straw bedding in sheds, but SACs Basil Lowman says the real potential is for outdoor corrals.

"Environmentalists want cattle to be kept outdoors but they do not like the sea of mud round ring feeders. These chips could provide the answer because rain will wash muck away and animals will be free from housing problems such as pneumonia," he said.

He thought the chips, at least 30cm (1ft) deep and topped up each year, would last for three years. Even as a bedding in houses, wood chips would work out cheaper than straw. Dr Lowman said the same system could be used for sheep to prevent poaching of fields during winter.

More resistant

A CHALLENGE from bovine viral diarrhoea dramatically lowers resistance of cattle to a whole range of diseases, SAC researchers have found.

"We had a pneumonia problem in one of our houses and despite improving the ventilation still had mortalities," Basil Lowman told visitors at the open day.

However, when post-mortem examinations were done, it was found that the cause was not viral pneumonia but one triggered by the pasteurella bacteria.

"We also tested for BVD and found infection which had come from a carrier calf. We are now convinced that BVD is not only causing its own problems but is lowering the resistance of cattle to all diseases.

"We would advise farmers to rid their herds of this problem – it will remove a lot of the niggles you get in cattle year after year," said Dr Lowman. &#42

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