A European research consortium tests commercial feed additives and combinations of products to reduce Campylobacter in broiler chickens prior to harvest. The mission of the Campybro project is to get the bug under control on farm. Results look promising.
It is not surprising anymore to find alarming news in European media about Campylobacter in broiler chicken meat. While there is a large variation in published data from surveys and specific cases, Campylobacter prevalence of more than 70% is frequently reported for the market in Europe.
As with other foodborne pathogen reduction strategies, the primary focus for controlling Campylobacter contamination is on sanitation in the processing and retailing sectors. Pre-harvest recommendations basically remain directed towards biosecurity. The reason is simple; the poultry industry does not yet have an effective and widely recognised solution to reduce Campylobacter in live birds. Even with such a solution, there is still the challenge of applying it successfully in different countries and production systems.
Experts seek solution for Campylobacter in poultry meat
Fortunately, a large, diverse group of experts are actively seeking a comprehensive solution to reduce the risk of Campylobacter in broiler meat by fighting this persistent pathogen in flocks from day one. This consortium, working under the umbrella of the Campybro Project, brings together the expertise of 10 research institutions, industry associations, and companies in four European countries. This independent, collaborative project is sponsored under a grant from the European Union for research, technological development, and demonstration.
During 2015, results from several initial trials within the Campybro Project were presented at various scientific forums in Europe (Czech Republic, United Kingdom, Italy, France, and Spain) and elsewhere (New Zealand, South Africa, and the United States). The first two full peer-reviewed articles about the use of available products to fight Campylobacter in live birds in Europe were published recently in the journal Poultry Science.
Also interesting: Combatting Campylobacter in Europe
With Campylobacter causing serious human health issues, supermarkets are pressuring producers to lower meat contamination. Management measures have obtained results but there remains much to do with regards to research in which additives and physical measures lead to the best reduction.
Variety of broiler feed products tested
Products for inclusion in broiler feed tested in this first phase of the project - a total of 24 along with a number of combinations - are identified by their commercial or trade names and generic characterisation. Most of the products are commercially available now, although some are still under development. The products include organic acids, fatty acids, monoglycerides, plant extracts, probiotics, essential oils, flavouring compounds, and a unique, proprietary, precision fermentation product characterised by the authors as ‘prebiotic-like’ and tested only as a stand-alone product.
It is important to note this fermentation product is listed in the European Union’s Catalogue of Feed Materials (category 12.1.5) and is not a ‘feed additive’ according to EU regulations.
A first battery of 12 products (Part A) was evaluated at the facilities of the French Agency for Food, Environmental and Occupational Health Safety (ANSES) in Ploufragan, France, in an experiment with 688 one-day-old Ross PM3 male and female broiler chicks. Each product was tested once and three trials were conducted to cover all 12 products, always against a positive control. The fermentation product was included at 1.25 kg/MT of feed. Chickens (45-40 per group) were randomly assigned to the treatments from day one and all birds were individually inoculated with Campylobacter jejuni (100 μL oral suspension) on day 11. Campylobacter caecal counts were performed in sub-samples of birds at 2, 5, and 6 weeks of age (3, 24, and 31 days post-challenge).
Although 10 of the 12 products showed reductions in Campylobacter counts at some point during the trials, half of the products showed effects only up to day 14. However, at the end of the study on day 42 (Figure 1), the fermentation product showed the highest mean reduction in Campylobacter counts - the only product with over 3 log reduction. Also, the fermentation product’s reduction of Campylobacter was the most significantly different from the averaged control groups of the 3 trials at 42 days (P < 0.001).
Figure 1 - Effect of dietary treatment on Campylobacter counts (log10 CFU/g) in the caeca of broilers at 42 days of age (31 d post-inoculation).
The research of the Campybro Project is ongoing. Combinations of products and other strategies, such as vaccination programmes and feeding management, are being evaluated in different modules.
There remains a number of challenges to conducting this type of research. Often there is high variation in levels of Campylobacter infection or contamination in the birds. Also, testing so many possible solutions together sometimes dilutes the power of the trials and the application of the results under commercial conditions.
Diamond V is committed to the goal of bringing safe food to consumers worldwide. The independent testing of a precision fermentation product in the Campybro Project confirms Diamond V research on food safety and poultry, which includes 24 trials completed in less than four years, including research in the USA summarised (see box). This growing body of research helps support the patent pending use of a fermentation product in pre-harvest reduction of foodborne pathogens in food animals, which was announced last year. For 2016, there are 12 Diamond V controlled research projects in place for poultry and half of the projects related to food safety are focused on Campylobacter in pre-harvest broilers in Europe.
Campylobacter research in the USA
In the USA, pathogenic bacteria such as Salmonella, Campylobacter, and Escherichia coli are frequently associated with consumption of animal protein products and are often cited among the top five pathogens causing foodborne illness. Despite significant progress by the poultry industry in reducing foodborne pathogens, the high rate of human illness persists. Poultry companies are seeking effective pre-harvest food safety programmes in order to lower the risk of human illness. While most pre-harvest food safety research continues to focus on Salmonella, there are also recent studies of Campylobacter in broiler chickens and turkeys.
Researchers (McIntyre et al., 2014) found that broiler chickens challenged with Campylobacter had lower prevalence and numbers when fed a unique, proprietary, precision fermentation product as compared to control broilers not fed the product. Birds were fed either the fermentation diet in the diet or a control diet, then inoculated with C. coli at 14 days of age. Caeca were collected and analysed at 42 days of age from 10 non-inoculated broilers (exposed to horizontal transmission) per pen. Caeca from birds fed the fermentation product had significantly lower prevalence than birds fed the control diet (1.3% vs. 17.5%, respectively, P = 0.02). Numbers of C. coli in the caeca of birds fed the fermentation product were lower than those fed a control diet (1 vs. 37 MPN/g, respectively, P = 0.09).
Other researchers (D. Smith et al., 2014) found that turkey hens inoculated with Campylobacter coli had significantly (P < 0.05) lower prevalence and numbers in the caeca at 84 days of age when fed a unique, proprietary, precision fermentation product as compared to hens not fed the fermentation product in the diet. At 70 days of age, five turkey hens in each pen were inoculated with C. coli; at 84 days, caeca from both inoculated and non-inoculated hens were collected and evaluated for C. coli. The pathogen prevalence was significantly (P < 0.05) reduced in non-inoculated birds (exposed to horizontal transmission), from 93% to 75%, and overall C. coli was reduced by one log (from 4.5 to 3.5 log10) for fermentation product-fed turkey hens when compared to control hens.