“Normal intestinal villus development is entirely dependent upon colonization by pioneer colonizers,” said Dr. William Hargis, sustainable poultry health chair, Center of Excellence for Poultry Science, University of Arkansas. Providing broiler chicks with a large enough quantity of beneficial bacteria to colonize the birds' guts shortly after hatch also allows for normal intestinal acquired and innate immune function to develop as well.

Hargis discussed the benefits of using appropriate probiotics treatments for broilers during the WattAgnet.com webinar, “You never have to recover from a good start: The importance of early flock performance and recent innovations in hatchery probiotics,” which was sponsored by the Pacific Vet Group. He said that the immediate post-hatch period is a critical time for the development of the chick’s digestive tract. Chicks must undergo the transition from energy supplied by the endogenous nutrients of the yolk to exogenous carbohydrate-rich feed. During this time, dramatic changes occur in mucosal development, morphology and function. He said that the timing and occurrence of these changes is “entirely dependent upon appropriate microbial colonization.”

Exposing the chick to a sufficient quantity of the appropriate probiotics mixture before it is exposed to other microbes can improve the effectiveness of the probiotics. Application in the hatchery gives the probiotics bacteria a head start on colonizing the chick's digestive tract, before the chicks will be exposed to the bacteria and fungi in the broiler house.

Symbiotic relationship

The intestinal microbiota of the chicken can aid the health and growth of the bird by fermenting carbohydrates, producing short-chain fatty acids, metabolizing proteins, and enhancing mineral and lipid absorption. Early establishment of the intestinal microbiota promotes proliferation and differentiation of epithelial cell lineages, regulates angiogenesis, modifies the activity of the enteric nervous system, extracting and processing nutrients in the diet, assembly of the gut-associated lymphoid tissue, and education of the immune system.

Hargis said the most beneficial pioneer colonizers of the gastrointestinal tract must competitively establish within the neonatal intestinal tract, displace opportunistic pathogens to which chicks are commonly exposed as early as hatch, stimulate enteric development and integrity, and must create favorable niches for eventual colonization by complex beneficial microbiota. Selection for bacterial strains that can meet all of these criteria is an essential part of the development of a truly effective probiotics culture.

Field trials

Dr. Ross E. Wolfenden, vice president of research and development, Pacific Vet Group, and Dr. James Barton, technical service director, Pacific Vet Group, presented results of large field trials, one with 9 million broilers, of hatchery-applied probiotics, FloraStart, in the U.S. The probiotics-treated birds had higher weights, with greater uniformity, and lower mortality at seven days of age. In the 9 million broiler test, the livability and weight gain improvements carried through to market.