I. Van Overbeke

The purpose of the present cross-sectional study was to evaluate the health status of organic broiler chickens and the contamination rate with Salmonella and Campylobacter in organic broiler production in Belgium. The broilers were screened for antibodies against routinely monitored poultry diseases at 1 day old and at slaughter. Fecal examination for the presence of worm eggs was done at slaughter. Bacteriological examination for the detection of Salmonella and Campylobacter was performed at day 1, week 2, week 4, week 7, week 10, and slaughter. Conventional broilers of the same poultry integration and reared in the same geographic area were also screened and served as reference. Serologic data indicated lower antibody titers against infectious bronchitis and Newcastle disease in organic flocks. No significant differences could be found in prevalence of Salmonella between organic and conventional broilers at slaughter. In contrast, Campylobacter infections at slaughter were significantly higher in organic flocks. Organic flocks most probably become infected with Campylobacter between week 7 and week 10. Worm eggs were found in neither the organic flocks nor the conventional flocks. In conclusion, there are indications that the respiratory health status is better in organic broilers but that organic flocks are more often infected with Campylobacter than are conventional flocks.

Abstract The efficacy of two inactivated vaccines containing the Apx toxins of Actinobacillus pleuropneunwniae (Hemopig™, Biokema, Lausanne, Switzerland and Porcilis™ App, Intervet, Boxmeer, the Netherlands) was determined. Ten pigs were vaccinated twice with Hemopig™ and eight pigs with Porcilis™ App. Ten control animals were injected twice with a saline solution. Three weeks after the second vaccination, all pigs were endobronchially inoculated with 10’ colony‐forming units (CFU) of an A. pleuropneumoniae serotype 9 strain. Increased respiratory rate and/or fever were observed in all vaccinated and control pigs after challenge. One pig of the Hemopig™ group and of the Porcilis™ App group died, whereas all pigs of the control group survived the challenge. Surviving pigs were killed at 7 days after challenge. The mean percentage of affected lung tissue was 34% in the control group, 16% in the Hemopig™ group, and 17% in the Porcilis™ App group. A. pleuropneumoniae was isolated from the lungs of all 10 control animals, from 7 of the 10 animals vaccinated with Hemopig™ and from 5 of the 8 animals vaccinated with Porcilis™ App. The mean bacterial titres of the caudal lung lobes were 1.4×106 CFU/g in the control group, 1.7×103 CFU/g in the Hemopig™ group, and 4.8×103 CFU/g in the Porcilis™ App group. In both vaccinated groups the mean number of days with dyspnoea, the mean number of days with fever, the mean percentage of affected lung tissue, and the mean bacterial titre in the caudal lung lobes were significantly lower than in the control group. Significant differences between the two vaccinated groups were not observed. It was concluded that both vaccines induced partial protection.