Poultry research looks at cages and campylobacter

Each spring, the World Poultry Science Association hosts presentations from the leading lights of research. Jake Davies reports from the latest meeting in Nottingham

Considering cages for beak trim ban

Bird breed rather than extra enrichments has the greatest impact on feather pecking, according to a study into the effects of keeping non beak-trimmed flocks in enriched cages by Scotland’s Rural College (SRUC).

“Beak trimming itself addresses the symptoms of injurious pecking and not the actual cause,” post-graduate Krysta Morrisey told the WPSA Spring Meeting. “It reduces mortality and morbidity, but there are also negative implications for both bird welfare and public perception.”

Ms Morrissey said there was a lack of research concerning untrimmed hens in enriched cage systems, even though 50% of eggs in the UK are produced in them.

The experiment took place on a commercial cage unit, looking at the use of enrichments and the effect of beak trimming on both Hy-Line and Lohmann Brown birds. Some 5,120 hens were studied – 80 in each cage – with an equal amount of each breed. Half had trimmed beaks and half untrimmed.

The breeds were chosen for their popularity in the UK, and because Lohmann Browns are used in countries that have banned beak trimming, Ms Morrisey explained. Birds were kept from week 19 to depopulation at 70 weeks.

Further enrichments beyond the legal minimum were also introduced to a number of cages: propolythene rope, two pecking mats made of crushed woodfibre and two beak blunting boards comprising an abrasive paste on plastic.

The only significant factor that emerged over the course of the study was breed, said Ms Morrisey. The non-trimmed Lohmann Brown birds were found to have a higher propensity to peck and two cages containing the birds had to be culled out because of an outbreak of aggressive pecking.

The presence of the enhanced enrichments had no significant impact, her study found.

Helping hand for emergency killing

A new mechanical slaughter glove that guides the hand to a perfect cull in poultry is being developed by SRUC academic Jessica Hopkins, in an effort to standardise on-farm emergency killing.

An estimated 9.1 billion birds are killed on-farm each year, for reasons such as farmgate sales, sickness, injury and stock control, she explained. “How these birds are killed is incredibly important, not just for the individual, but to bird welfare on a large scale.”

Traditionally birds are “necked” if they need to be culled out. But new Welfare at Time of Killing legislation, introduced in January 2013 has “heavily restricted” this.

“One stockman can now only do 70 birds per day,” Ms Hopkins said. “Also, you can now only perform manual cervical dislocation on birds that weigh under 3kg, and mechanical cervical dislocation on birds that weigh under 5kg.”

Ms Hopkins’ project has looked at ways to both standardise emergency slaughter and to develop a mechanical slaughter method that’s simple to use.

Initially she set up a study comparing four devices, modified to become effective mechanical or enhanced manual slaughter devices. Subsequently, a novel glove, which protects a stockworker’s hand while guiding it via metal rods to the ideal position for neck dislocation, is now being taken through further on-farm trials.

Campylobacter in the spotlight

A study led by SRUC on biosecurity interventions suggests they may not significantly reduce campylobacter levels on farm.

The project involved 24 commercial broiler sheds – 12 controls and 12 where biosecurity interventions were adopted, including fly screens, water treatment and physical hygiene barriers at shed entry.

Preliminary results found 80% of farms tested positive at post thin, compared with 47% pre-thin. And it was found that no interventions “had any significant effect”, according to SRUC’s Nick Sparks.

Further number crunching found some farms had a predisposition to test positive for campylobacter. Of the 24 sheds, six were positive every time over the eight crop cycles tested.

Recent work looking at different biosecurity interventions suggested it could keep campylobacter levels down, but Prof Sparks questioned if constant adherence was feasible.

He said a rapid, on-farm test that was sensitive to the level of campylobacter would be the most effective way to maintain strict sstandards.

Litter management most effective against feather pecking

Dr Sarah Lambton, of Bristol University, presented findings into the effect of different flock management techniques on injurious feather pecking.

She told the meeting that much of the previous work in this area had been lab-based, which didn’t translate well to commercial sheds. Dr Lambton presented a recent trial that had been an attempt to overcome this lack of knowledge.

The study investigated the effect of 46 different strategies for farmers to undertake on 47 flocks, and 53 control flocks. Both treatment and the control flocks had a mixture of untrimmed and beak-trimmed birds.

The more management strategies employed, the lower feather pecking was as a whole, she said. But those which focused on litter quality and utilisation were found to be the most effective.