The average consumer in the US ate 17.6 pounds of turkey meat in 2008, making turkey the fourth most popular form of animal protein as measured by per capita consumption, behind chicken, beef and pork. According to the Poultry Science Association (PSA), some researchers are now helping producers meet the demands of the thin slice of this market seeking 'natural fed' birds – turkeys whose diets are organic, contain no animal protein products and are antibiotic-free.

Dr Michael Hulet, associate professor in Penn State University's Department of Poultry Science, estimates that antibiotic-free (ABF), organic turkey represents approximately 2.3 per cent of the total number of turkeys produced each year in the US. That translates into about six million ABF turkeys out of roughly 270 million turkeys produced in the US annually. Much of the ABF turkey meat is sold, according to Dr Hulet, to up-scale speciality retail stores in the North-east, though shelf space is also now being provided for ABF turkey meat in many other retail outlets as well.

The relatively recent demand from a small segment of consumers for ABF turkey is one offshoot, says Dr Hulet, of the diversification of turkey products in the marketplace.

"Turkey consumption in the US has increased nearly 300 per cent since 1970, largely due to the growing variety – and increasing quality – of turkey products being made available by producers, ranging from cuts and parts to further processed products. The demand that producers are seeing from some consumers for antibiotic-free turkeys is a great illustration of just how flexible turkey producers have to be today to meet the demands of all segments of the market. Poultry scientists are working to help them meet that demand," said Dr Hulet.

Antibiotic use in turkey production

Producers typically add antimicrobials to commercial turkey diets to improve livability, feed efficiency, meat quality and growth. While this use of antimicrobials is established practice and has long been known to be safe to humans, the advent of work on developing ABF turkeys, according to Dr Hulet, was driven by the concern among some consumers about the development of antibiotic-resistant bacteria as a result of the normal use of antimicrobials in turkey feed.

"In response to demands from a relatively small group of consumers, turkey producers have looked to poultry scientists to help them explore alternative feed ingredients to the use of antimicrobials. Researchers have responded by helping to develop and test alternative forms of additives that have effects similar to antimicrobials. For example, some additives formed as fermentation products – yeast by-products, such as mannan-oligosaccharides – partially mimic antimicrobials by changing the microbiological florae in the digestive tract while also eliminating potential pathogens that would otherwise diminish growth productivity," said Dr Hulet.

While yeast by-products have to date, says Dr Hulet, met with varying success in terms of promoting growth and growth efficiency, other prebiotics, such as oregano, fructo-oligosaccharides, chicory and probiotics have been proposed to help replace the use of antibiotics and growth promoters with some nutritional supplements that have shown promise in sustaining turkey growth and performance. ABF turkeys have mortality rates that are one to two per cent higher than non-ABF turkeys. This fact, along with lower placement densities, increases the production costs of this segment of the industry. Hence, other nutritional and management research is needed to help this segment of the industry.

Researchers have also shown other non-nutritional strategies to mitigate bacterial levels in turkey houses, such as sterilisation of litter by in-house composting, use of nipple drinkers and improved ventilation systems to enhance environmental conditions in the house and decrease the bacterial challenges to the growing ABF turkeys.