Competitive exclusion against Salmonella Enteritidis in layer chickens by yoghurt microbiota: impact on egg production, protection and yolk-antibody and cholesterol levels.

AIMS: This work aims at studying the impact of competitive exclusion of Salmonella serotype Enteritidis infection in layer chickens, by microbiota of fresh and dried-modified yoghurt, on egg production and weight, protection against infection, and on yolk-antibody and cholesterol levels. METHODS AND RESULTS: Four groups of 27-week-old layer chickens were included in this study. After an initial enrofloxacin treatment, groups 1 and 2 were administered fresh or dry yoghurt (respectively) for 14 days. Groups 1, 2 and 3 were challenged intraoesophageally with Salm. Enteritidis, on the sixth day of yoghurt administration, while group 4 was left unchallenged and without yoghurt administration. No significant difference in percent infectivity of visceral organs with Salm. Enteritidis was observed between the groups. The yoghurt administered groups showed an early significant antibody response in their yolk on the seventh day postchallenge (P < 0.05) and highest egg production and weight. Finally, the egg yolk cholesterol concentration was higher in Salm. Enteritidis-challenged groups than that observed in the unchallenged group. CONCLUSIONS: The results point to the possible involvement of yoghurt administration in immunopotentiation and improvement of egg production and weight. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings warrant further research that could improve immunity and production in layer chickens infected with Salm. Enteritidis.

Avian influenza outbreak in poultry in the Lebanon and transmission to neighbouring farmers and swine.

Twenty-four poultry farms in four major provinces of the Lebanon were investigated to verify the first emergence of avian influenza (AI). Both the meat chicken breeders and commercial chicken layers presented a significant average drop in egg production equivalent to 46% and 47.3%, respectively. However, the average drop in egg production in the free-range layers was only 11.1%. Flocks were confirmed as positive for AI by ELISA, clinical signs and pathological lesions. The pathogenicity, including case fatality in affected chickens, was different depending of the types of chicken and farming conditions. The average fatality rates among breeders, commercial layers, free-range layers and broilers were 2%, 2%, 1% and 35%, respectively. The majority of the randomly selected ELISA-positive serum samples collected from different farms showed H9-specific haemagglutination inhibition (HI) antibodies. The direct immunoflorescent antibody test also revealed the presence of H9 antigen in congested brains and in tracheal lesions of broilers. The virus isolated from the brains of broilers was subtype H9N2. Pigs fed with carcasses of affected chickens showed H9-specific HI antibodies at 100%. Farmers (32.3%) serving the affected chickens also revealed these antibodies in their sera.