Evaluation of in-field efficacy of dietary ferric tyrosine on performance, intestinal health and meat quality of broiler chickens exposed to natural Campylobacter jejuni challenge

Campylobacter is an important pathogen commonly found in chickens that can cause severe acute gastroenteritis in humans. Despite intensive efforts to inhibit food-borne transmission of Campylobacter no effective strategy exists to reduce Campylobacter loads in farmed broilers. This study examined the capacity of a novel feed additive to lower Campylobacter jejuni populations and to improve growth efficiency of broiler chickens. A total of 384 male one-day-old broiler chicks were used in a 42-day trial. Birds were randomly allocated into four treatments with six replicates of sixteen chicks per pen. Three groups were fed the basal diets further supplemented with TYPLEX™ chelate (ferric tyrosine) at various concentrations (0.02, 0.05 and 0.20 g/kg, groups T2–T4, respectively). Control group (T1) was fed basal diets in mash form that did not contain added ferric tyrosine. Feed and water were provided ad libitum. At 20 days of age, broilers were exposed to natural C. jejuni challenge by introducing contaminated litter from a commercial farm. At day 25, pen litter samples analysed positive for C. jejuni, and the infection intensity was homogeneous among pens. At the end of the study C. jejuni counts in bird caeca were significantly reduced, by 2 log10 in the T4 group, compared to the T1 Control and T3 groups (p = 0.004). During this study, a natural infection with Eimeria tenella occurred at days 26–29. For animal welfare reasons all birds were treated with an anti-coccidial drug as recommended, for two consecutive days. At day 42, diarrhoea was observed on the litter in only 1 of 6 pens in the T4 group, but in 5 of 6 pens in the T1 Control group. In addition, autopsies showed that the T4 group had the highest percentage of birds with normal intestinal tracts. The T1 group had the lowest percentage of birds with infection-free tracts, and higher incidence of coccidiosis and bloody diarrhoea. At 42 days of age all birds were slaughtered and samples collected for further analysis. Birds in the T4 group tended to exhibit improved weight gain and feed efficiency, a result that warrants further investigation. Collectively, our data suggest that addition of ferric tyrosine at 0.20 g/kg exerts a protective effect against C. jejuni and coccidiosis.