Antimicrobial Use – Case Study in Poultry

Bruce Stewart-Brown, DVM, Diplomate ACPV

Perdue Farms, Inc

Salisbury, MD

The management factors associated with optimizing today’s broilers continue to change and evolve. In the past five years we have spent considerable time identifying those factors that are most successful in achieving healthy, efficiently grown broilers (that result in high quality, safe chicken) with an antibiotic use philosophy that does not embrace “growth promotion”.

There are multiple challenges. Our approach has involved incorporating our knowledge of the bird to devise strategically designed immunization programs and emphasizing management programs aimed at providing the optimal environment for young birds to thrive. The management stressors have come in the form of less than optimal temperature, air, light, feeding patterns, and distribution of birds within the house.

Infectious stressors can occur following management stressors. They come in the form of respiratory viruses (results in excessive sneezing, snicking), particularly in houses with poor air quality. Excessive cycling of coccidiosis and bacterial enteritis (gut infection) may be evident in houses that are cold, wet, crowded, or when birds are not eating regularly (out of feed, control pan management, poor migration from brood chambers).

Increased focus is on the whole time the birds are in the house but the first 3 weeks are crucial. A bird – using human terms – goes from being an infant to a teenager in the first 4 weeks of its life. It is building immunity to coccidiosis, respiratory viruses, Marek’s disease, as well as many other diseases. All the chicks help from the hen has been diminished by the time it reaches 4 weeks old. Support through this time is crucial. Once immunity to these diseases is established, this chicken is efficient and healthy through the maximum growth phase of the flock.

We have relied on immunity and will continue to try and optimize this through genetic selection in the primary breeding program, good vaccination programs, and nutritional support and supplementation. Optimal environmental support makes a big difference in the success of these approaches.