E. coli Related Condemnations in Ontario Turkey Flocks

Dr. Bruce Hunter's lab recently reported on a study to investigate the importance of E.coli related condemnations in Ontario turkey flocks. The initial part of the study was a scanning of the condemnation records for 4 large turkey processing plants from 1991 to 1997. The findings of this survey indicated that cellulitis and airsacculitis, in both hens and toms, and hepatitis in broiler turkeys, were the most important reason for condemning carcasses.

A second part of the study involved the following of turkeys from 8 large turkey facilites from poult placement to processing. Since the results of the initial survey indicated that condemnation loses were due mainly to E.coli triggered conditions and were more severe with heavy toms, only toms were monitored in this part of the study. The data collected was targeted to answer questions such as, serogroups and source of E.coli, litter bacterial build-up, air quality and the interaction of all these on flock performance and health.

The data generated indicated that three particular E. coli serogroups were important in causing acute outbreaks of collibacillosis in young poults. While other serogroups were isolated, their appearance was much less frequent. The presence of E. coli at any time during the growing period resulted in decreased flock performance. It was possible to isolate pathogenic E.coli serogroups in cleaned and disinfected barns, thus demonstrating that the organism can readily survive in barns between crops. Isolation of the organism from day old poults suggests that hatcheries could be a potential source of the problem. While over 55 other E.coli serogroups were identified, from cellulitis lesions at processing, these are not recognized as major disease causing strains. It is assumed that airsacculitis and cellulitis are the result of similar and potentiating, but not highly pathogenic strains of E.coli,gaining access to birds that are going through some type of stressed condition. This assumption is strengthened by the fact that high levels of E.coli alone were not necessarily associated with increased condemnations. High ammonia levels appear to result in damage to the respiratory tract allowing E.coli access even when bacterial levels in the litter are low.

Cellulitis condemnations were more common in heavy turkeys, versus broilers, and with good performing flocks, in pens with low humidity and high litter bacterial counts. It is suggested that fast growing birds would spend more time off their legs and thus have their breasts in contact with dry, abrasive litter, which could result in skin damage leading to bacterial entry and thus infection.

The authors point out that there was a trend for coliform bacteria levels to increase in the litter during the grow-out period, while E.coli levels were not increased, from that noted at the end of the brooding period. Since litter contains a complex mass of living organisms the possibility of manipulating the composition of these organisms to help to reduce specific bacterial loads, is an interesting concept.

E.coli health problems are a major source of concern for all segments of the poultry industry. In spite of all the advances made in improving pen environment, biosecurity, and animal health, the economic losses in Ontario attributed to E.coli are still very high. There is no question but this is an area that needs increased funding, as well as personnel, if Ontario is to continue to excel in the production of quality poultry products.