In the US, as of 1 January, the federal Food and Drug Administration eliminated the use of medically important antibiotics for growth promotion and expanded the list of feed-grade antibiotics that are classified under Veterinary Feed Directive drugs. This means the antibiotics used in animal feed, which had been available over the counter, now require a veterinarian to sign off on their use. Drug companies have also removed statements on their labels under the VFD regulations concerning growth promotion and feed efficiency - that basically keeps veterinarians from writing prescriptions for these uses.

Charles Hofacre, a professor and director of clinical services at the University of Georgia’s college of veterinary medicine in Athens, called the new regulations “one of the most significant changes” he has seen in his 30-plus year career in the industry during a speech on 31 January at the International Production & Processing Expo in Atlanta.

Scientists in the industry have been looking elsewhere besides antibiotics for ways to promote poultry health and growth and one area of intense interest is in probiotics, the same kind of good bacteria that you get when you eat yoghurt.

One of the newest efforts that is showing promise is the use of probiotics administered to chicks before they hatch. Researchers from Chr. Hansen, the global bioscience company based in Denmark, and Mississippi State University have found that administering GalliPro® Hatch - a new probiotic formulation for poultry that contains a strain of Enterococcus faecium - to chicks before they hatch has shown improved chick health without impeding hatchability.

According to Aaron Kiess, a poultry science professor at MSU, the study involved nearly 4,000 fertile eggs from a broiler breeder flock. One group of eggs was injected with a vaccination for Marek’s disease, a highly contagious Herpes virus infection in chickens, and a second group received the Marek’s disease vaccination and GalliPro® Hatch. The probiotic was injected into the egg’s amniotic fluid that bathes the chick. The injections were administered on the 18th day, the time when a bulk of the fluid is ingested by the bird and taken up into its intestine, allowing the E. faecium to reach the intended target.

The researchers hatched the eggs followed by a seven day grow out since, says Kiess, “mortality in the first seven days of life are a big indicator of how production will go for the rest of the flock.” He said compared with the control group they were able to reduce mortality without negatively impacting the number of eggs that hatched, which is important since “the more chicks we hatch the better the production for the company will be.”

Compared to the vaccine group, the vaccine plus GalliPro® Hatch group had fewer late-dead mortalities before hatch and lower mortality zero to seven days post-hatch. They also had numerically higher average weights at hatch than those that received the vaccine alone, according to Kiess’ research. Kiess said that getting the probiotic to the chick before it is exposed to any harmful bacteria in the hatchery gives that chick a better opportunity to be free of disease but also helps in nutrient absorption and stimulating the immune system.

Herb Kling, a poultry consultant for Chr. Hansen, said the period just before the chick hatches is a critical time since it is “gearing up to begin breathing oxygen, eating solid food, drinking water, and will have to deal with environmental stresses” so the sooner the birds can establish beneficial microflora in their guts, the healthier they will be.

“Bacteria such as Clostridium, Salmonella, and E. coli are all intestinal pathogens and you have to obviously keep them in check or you're going to have an unhealthy animal, not only as a chick but all the way through life,” said Kling in a phone interview. “If you damage the intestinal tract or don't have an optimum intestinal tract early in life it's going to impact the performance of that animal all the way through life. This probiotic in ovo application is one tool that's going to provide an additional benefit for the most healthy and cost effective broiler.”

Both men believe probiotics will be playing an essential role for the industry as it moves away from antibiotics, but because of the outsized role antibiotics have played - and the fact that they work very differently than probiotics - it will take other things such prebiotics, essential oils, specific enzymes in the diet to help boost nutrient absorption for optimum growth, and, most importantly, good management to replace them.

“Probiotics are going to be absolutely important going forward for the industry. They are one tool to help when we can no longer use everyday antibiotic therapy applications, but good management is also going to play a role in the ultimate successful antibiotic-free production,” says Kling.