9 January 1998

Racks root out tail biting

Allowing pigs to root can

help stop tail biting

outbreaks and ensure better

feed conversion.

Emma Penny reports

MAKING pens more luxurious and allowing pigs to root can help improve behaviour and feed conversion efficiency.

Thats according to results of a trial carried out at the Agri-cultural Research Institute of Northern Ireland, Hillsborough, Co Down.

According to ARINI pig specialist Violet Beattie, pigs have a behavioural need to root, but this is often not allowed in intensive systems.

"From initial trials, we found that enriching the pigs environment had a much greater effect on behaviour than increasing space allowance.

"In intensive pens we noted a lot of aggression – pigs spent 9-10% of their time chewing walls, doors and feeders and 23% of their time indulging in harmful social behaviour, whereas pigs in an enriched environment spent a third of their time rooting which is more natural behaviour," explains Dr Beattie.

From that, she concludes that pigs have a natural need to root. "We then looked at what the best rooting substrate was in communal pens."

Peat, straw, spent mushroom compost, sawdust and sand were compared against concrete. Surprisingly, straw came out worst – it was least liked by pigs after concrete, she says.

"The pigs liked peat best, but we are no longer allowed to use it, so the spent mushroom compost, which came second from top was the option chosen for further trials at Hillsborough."

Spent mushroom compost, which is in abundant supply in Northern Ireland, was obviously unsuitable for use on the floor. "We decided to scatter it on mesh racks suspended about 1.5ft from the floor. This meant pigs could root at it from below."

Putting racks of compost in with tail docked pigs reduced harmful social behaviour, with no tail biting recorded. "We then decided to compare behaviour in pens with and without racks where tails had not been docked. Where there was no potential to root, tail biting ran at 12-14%, but this was reduced to zero where the rack was included," says Dr Beattie.

Where pigs had access to the rack, and were allowed to root, feed conversion improved by 5%, she says.

"The inclusion of the rack means that pigs havent been wasting feed by rooting in troughs; one teaspoonful of feed spilled/pig/ hour reduces feed conversion by 5% – and you wouldnt even notice that level of feed loss although it adds significantly to costs."

To date, about 20 producers in Northern Ireland are using the rack system, choosing to put racks in to stop tail biting outbreaks. "This stops outbreaks within a day, but the rack cannot be taken out until slaughter or tail biting will recommence."

Despite its success, Dr Beattie acknowledges that there are concerns with the system. "Spent mushroom compost isnt widely available to everyone, so we are about to embark on another project looking at alternative rooting materials such as shredded paper.

"We also need some way of automatically dumping rooting material onto racks as a pen of 20 pigs require about a bag of spent mushroom compost a day. However, producers reckon the time taken to do this is nothing compared with treating a tail biting case."

According to Dr Beattie, tail biting costs over £2 a finished pig sold – excluding medical treatment and labour costs. Mushroom compost racks cost less than 25p a finished pig sold – including cost of collecting the compost and labour for filling the racks.

Violet Beattie… enriching pigs environment had a greater effect on behaviour than increasing space allowances in their pens.

ROOTING RACKS

&#8226 33% of time spent rooting.

&#8226 Reduces tail biting.

&#8226 Better feed conversion.

Allowing growing pigs to root in spent mushroom compost on suspended mesh racks eliminates tail biting and improves feed conversion by 5%.