E. N.C. Tessari

Serovars of Salmonella spp isolated from broiler chickens and commercial breeders in diverse regions in Brazil from July 1997 to December 2004

Avian salmonellosis is a worldwide problem to the poultry industry, from the point of view of animal health and public health as well. The aim of the present study was to survey the most common Salmonella serovars in commercial breeders or broiler flocks from several regions in Brazil. The results of the present study indicated a high incidence of S enterica subspecies enterica serovar Enteritidis in breeders (57.5%) and broilers flocks (84.0%). The importance of these findings lies in the fact that S. Enteritidis has become the most frequent serovar responsible for foodborne outbreaks and sporadic cases of salmonellosis in humans.

Comparative Study of Serological Tests for Mycoplasma synoviae Diagnosis in Commercial Poultry Breeders

Avian mycoplasmosis causes great economic losses to the poultry industry, and one of the major agents involved is Mycoplasma synovie (MS). Serum from commercial poultry breeders (n = 2781) was tested for MS by serum plate agglutination (SPA), hemagglutination inhibition (HI), and enzyme-linked immunosorbent assay (ELISA). From 2,781 samples tested, 736 (26.46%) were positive in SPA. From 712 SPA-positive sera, 30 samples (4.21%) were positive in HI, and 150 samples (21.06%) were positive in ELISA. Copositivity between ELISA and HI was 90%, and conegativity was 82.0%. Agreement between HI and ELISA was rejected by McNemars test (P ≤ .001), and Kappa coefficient showed a weak correlation between the two techniques (k = 0.25; 0.21 ≤ k < 0.40). Weak statistical correlation was observed between all serological tests (SPA, HI, and ELISA), and they should only be used for initial screening for MS.

Humoral immunological response in broilers vaccinated against newcastle disease and supplemented with dietary zinc and vitamin E

The humoral immune response of broilers fed diets supplemented with Zinc (Zn) (0, 40, and 400mg/kg) and vitamin E (0, 12, and 120mg/ kg), separately or combined, was evaluated. A completely randomized design was used according to a 3x3 factorial arrangement, with nine treatments and four repetitions per treatment. Sexed birds (n=1440) were distributed in 36 boxes with 40 chicks each and reared until 41 days of age. Vaccination against Newcastle Disease (ND) was performed when birds were 14 days old. ELISA and HI tests were used to assess antibody levels before vaccination and at 28, 35 and 41 days of age. The results were analyzed using Proc Mixed from SAS. The interaction between the highest dietary levels of Zn and vitamin E resulted in higher antibody levels in ELISA at 14, 28, 35 and 41 days of age. Increasing levels of Zn and vitamin E supplemented separately in the diets provided greater levels of hemagglutinating antibodies in HI at 14, 28, 35 and 41 days old. The interaction between the highest levels of Zn and vitamin E resulted in greater antibody levels at 41 days of age.