27 October 1995

Wet feed move saves pig unit a handy £96/t

In the second of this series, Jonathan Riley visits one Shropshire unit where wet feeding has cut feed costs

WET FEEDING of by-products has reduced feed costs to £96/t or 30p/kg liveweight gained on one Shropshire farm.

Roger Pinches began wet feeding at his 200 ha (490 acre) Castle Farm, Shawbury, because pumping food from the mixing unit to the troughs was the easiest way to move feed around the farm.

The farm supports 180ha (440 acres) of arable and 240 Newsham N32 sows, farrowing mainly outdoors and producing about 100 bacon pigs a week. These are marketed at an average of 97kg liveweight through Meadow Valley Livestock, Stratford-upon-Avon. A further 360 sows are kept outdoors on rented land with the progeny sold as weaners.

"Feeding by-products carries risks because you dont know how well a new feed, that might look attractive on paper, will affect performance," says Mr Pinches.

To assess performance, therefore, pigs are weighed as they are moved into weaner, grower and finisher accommodation.

Wet feeding is not possible in the grower accommodation because it is sited away from the main site. Once in the wet fed, finisher accommodation, the main ingredients of the feed are by-products of the wheat processing industry, Abracarb and Abrapro.

Abracarb is about 30% dry matter and supplies energy in the form of starches at a meal equivalent DM cost of about £87/t. Abrapro is about 14% DM but can be as low as 8% DM and costs about £95.70/t on a meal equivalent basis.

Advice on ration formulation is supplied by Banbury Agricultures Caroline Bevan. "Concentrated whey is normally included in the finisher ration but recently this has been substituted with a new product that has a nutritional breakdown similar to cooked cereal of 15MJ/DE/kg DM and priced competitively.

"The new product has a variable salt level that can be quite high and could be damaging to pigs if the diet was not altered to compensate. To cope with the variation in nutritional breakdown, as diets are formulated they are printed out and kept on a card system," says Mrs Bevan.

A mix of cake (cooked cereals and cakes) and rapemeal is also fed to provide energy and protein at a cost of about £118/t.

A tonne of feed comprises 200kg oatfeed, 130kg cake/rapemeal 310kg soya and 340kg of the new product plus minerals. Overall the diet costs about £96/t.

The feed is mixed in a dry mixer and put into a holding bin above the liquid mixer with load cells.

"This accounts for about 55% of the ration and is added to Abracarb and Abrapro. Then, because of the variability in dry matters, water is added to fine tune the ration," says Mrs Bevan.

Because by-products are paid for on a £/% DM basis information on DM% is provided with each load of a particular product. Further analysis is provided by Banbury Agriculture.

This means that when a product arrives on farm with a certain DM% previous rations can be referred to and diets formulated rapidly.

The finishing pigs are fed ad lib and kept in either fully or partially slatted accommodation with automatically controlled natural ventilation (ACNV). One feeder to a pen of 20 pigs is positioned in the middle of one side of each pen.

Feed is pumped to the pens automatically. As chambers in individual feeders empty of feed, pressure switches first activate the wet feed mixer, to ensure feed has not settled out, and then trigger the pump to deliver more feed through the pipelines.

Mr Pinches says: "This system has cut electricity use. Previously the mixer was activated every 10 minutes to stop feed settling out.

"Liquid feeds increase intakes by up to 10% and help to reduce respiratory problems because there is less dust. "Ad lib feeding also reduces competition for feed so reducing stress. Because the pigs dont all get up at once there is almost no leg damage," he says.

"The major drawback is the variability in feed breakdowns which makes conversion ratios difficult to calculate.

"But the important measure is the cost a kg of liveweight gained which is about 30p a kg liveweight," he says.