Efficacy of a Chestnut-based additive to protect against fowl typhoid in laying hens

REDONDO E.; REDONDO L.; SALVAT A.; FERNANDEZ MIYAKAWA, M.; CHACANA P.

Paris

Simposio; 2nd International Symposium on Alternatives to Antibiotics; 2016

OIE (Organización Mundial para la Salud Animal)

Fowl typhoid is caused by Salmonella Gallinarum biotype gallinarum (S. gallinarum) and may lead to important economic loses in the global poultry industry, mainly due to mortality (from 10% to 100%) and drop of egg production in laying hens. The disease has been officially eradicated from commercial poultry in many developed countries, but still subsists as an endemic infection in most developing countries and non-commercial farms. Antimicrobial treatments are commonly used to reduce mortality but it is unlikely that treatment will completely eliminate fowl typhoid from an infected flock. Furthermore, in the last years augmented resistance of S. gallinarum strains for some antibiotics commonly administered has been observed. In this work, the use of chestnut extracts as an alternative to prevent or treat fowl typhoid was assessed. Sixteen-week-old laying hens were divided in 3 groups of 14 birds each. Hens from control group received commercial feed and hens from treated groups received normal feed plus 5 ppm of chestnut extract from 24 h before infection onwards (Group 1) or from 24 h after infection onwards (Group 2). All hens were orally challenged with 106 CFU of S. gallinarum and mortality was recorded for 10 days. Seventy-one percent (10/14) of the hens died from fowl typhoid in the control group. In the treated groups, mortality was of 36% (5/14) in Group 1 and of 50% (7/14) in Group 2. Reduction of the mortality was significant in the Group 1 (P= 0.0465) but not in Group 2 (P= 0.1886). Thus chestnut extracts may be useful to prevent fowl typhoid in the flocks, although once the animals are infected, the additive may not be completely efficient to reduce mortality. Combined strategies such as preventive feed additives, vaccination and biosecurity measures seems to be the most likely approach to improve the control of fowl typhoid and may help to eradicate the disease from countries where it is endemic.