The latest Turkey Science and Production conference offered delegates a wide range of topics and papers on health management. Here’s a taster.
A respiratory disease has risen four places up in an American survey of health issues in turkeys that ranks their economic impact.
Ornithobacterium rhinotracheale (ORT) was ranked as the third most pressing health issue in turkey production by professionals and veterinarians, up from seventh place in 2015.
The top concern was once again a lack of efficacious drugs for the sector, but ORT rising up the rankings was of note, according to Helen Wojcinski, of Hybrid Turkeys. She gave the conference an update on emerging disease trends.
“What we have seen over the past year, especially in parts of the midwest, is an increase in mortality in commercial turkeys, and ORT was often a significant component,” she explained.”
Turkey Reovirus was often found in conjunction with ORT, but it is not clear whether the conditions were linked – though one suggestion was that the stress caused by leg disorders could lower immune responses, said Dr Wojcinski.
There are no commercially available live vaccines, but controlled exposure has shown some promising results, she explained, with some farmers moving litter from barns with older birds to brooding sheds to provide exposure to ORT.
It’s likely that several different factors acting in concert and may be responsible for this upsurge in ORT, Dr Wojcinski added. One is new strains emerging that have not yet been categorised.
Among the reasons, production systems changing to ‘brood and move’ – a measure that reduces the risk of some diseases spreading – could be preventing young birds from developing resistance to the bacteria.
Biosecurity is also considered a critical factor – and it is still lacking in some farms. “People that went through high-path AI are a little more careful than others about not allowing wild birds into barns, but there’s still a lot of facilities where there may be birds nesting in – or nearby – the barn,” said Dr Wojcinski.
Another issue rising up the ranks for turkey producers is the integrity of legs, with the problem now seventh on the list of concerns about turkey production. Further research has discovered the issue is usually found in heavy toms, with a wide range of disorders identified. But the two primary causes were considered to be reovirus and nutritional deficiencies.
The problem has not gone unnoticed in Europe, added Dr Wojcinski, with chondrodystrophy in young birds, angular leg deformities in older birds and some shaky legs in breeders all being recorded. Again, feed analysis revealed issues with the nutritional profile of diets – and the idea that if not all birds are affected it can’t be the feed was roundly rejected. “In some cases when bone samples are analysed of clinically normal birds within the affected flock, microscopic evidence shows that clinically normal birds are affected.
“In other cases, the comment is that only one strain of turkey is affected, and not the other, so it can’t be related to the feed. This may reflect only the difference in early feed intake, where strains or birds with the highest feed intake are the ones most likely to be clinically affected.
“We need to be diligent and look at all potential causes of leg issues when a structural defect occurs.”
*This article is based on a paper delivered at the 12th Turkey Science and Production Conference, held near Chester, UK, in late March.