However, using alternative feeds can help keep costs down says the British Pig Executive (BPEX), but it is not a case of just switching feed.

Potatoes, carrots, sugar beet, silage and fodder beet are good alternatives, but nutritional balance and other factors must be taken into account. For example, to get the nutritional value of 1kg of concentrates, producers would need to feed 6kg of potatoes.

Root vegetables can be a cheaper feeding alternatives for cull sows.

The logistics of feeding bulky materials also have to be considered. It may also mean mixing both concentrates and potatoes/vegetables to maintain the correct nutritional intake.

BPEX Knowledge Transfer Manager Angela Cliff says it's a matter of quality and balance.

"The nutrients being fed must be properly calculated and other adjustments may be necessary to make sure the sows are receiving the correct vitamins and minerals. As long as all this is borne in mind, there is potential to ease the cost of feeding cull sows during this difficult time," she explains.

A handbook detailing the nutritional value of a range of alternative feedstuffs by Professor Sandra Edwards of Newcastle University is available from the BPEX KT Team. Go to www.bpex for more information.