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This study was to evaluate the possible genetic resistance of exotic and indigenous chicks to Salmonella gallinarum. A total of 72 nine weeks-old chicks were used for the study. The Fulani ecotype (Fulani smooth feathers - FSF), Yoruba ecotype (Yoruba smooth feathers - YSF), and the Exotic breed (Nera Black) chicks were infected with a dose of S. gallinarum (8.3 x 106 CFU) and were observed for 16 days. Evaluation of resistance was based on clinical signs, mortality, pathology, leukocyte count, bacterial count from liver and spleen of infected chicks. The highest peak for clinical signs in S. gallinarum infected chicks coincides with highest mortalities recorded on day 11-12 dpi and bacterial count of both liver and spleen on day 8. The lymphocytes count declined on day 8 for all the experimental chicks except for the exotic breed. There was no significant difference between the bacterial counts of the different groups on day 8. In S. gallinarum infected chicks, 94.4% of all the chicks showed clinical signs after infection, the exotic breed showed a prolonged clinical signs while the Yoruba ecotype showed the least. 87.5%, 80.0% and 37.5% mortality were recorded in the exotic breed, Fulani and Yoruba ecotypes respectively. The study showed that the exotic chicken (Nera Black) was more susceptible to Salmonella gallinarum infection. It also indicated that within the ecotypes in Nigeria, Fulani ecotype was more susceptible to Salmonella gallinarum infection than the Yoruba ecotype. The lower clinical signs and mortality observed in Yoruba ecotype indicated a resistance of the ecotype to S. gallinarum infection.Keywords: Ecotypes, Nigerian Indigenous chicken, Salmonella gallinarum infection.

This experiment was conducted to assess and compare the susceptibility of the varieties of Yoruba indigenous chicken ecotype: Yoruba Smooth Feathered (YSF), Yoruba Frizzled Feathered (YFF) and Yoruba Naked Neck (YNN) to Newcastle disease. A total of sixty (60) 16 weeks old chickens were used comprising of twenty (20) chickens per variety. The assessmentof their susceptibility to Newcastle disease was by evaluation of clinical signs, humoral response, mortality, pathology following contact with Newcastle disease infected chickens. The experimental chickens developed clinical signs of Newcastle disease from day 9 after infection. Haemagglutination inhibition (HI) titre was determined on days 0, 21and28 post-infection. On day 0, the HI titre of the 3 genotypes were below 3log2, on day 21, there were significant differences within the group (P

A study was conducted to determine the genetic resistance of two Nigerian ecotypes chicken and exotic breed cockerel (black Nera) to Newcastle disease by evaluating their clinical, haematological and humoralresponses to experimental Newcastle disease virus infection.. The chicks from the three genotypes were infected with 1ml of 105 ELD50 of Hertz 33 Newcastle disease virus inoculums orally. Their responses to infection weremonitored through clinical signs and mortality, haematological parameters and antibody titres values on days 0, 3, 7, 14 and 21 post infection. There was no adverse clinical manifestation and mortality in all the chicks throughout the experimental period. There was also no significant difference (p>0.05) between the mean packed cell volume of all the three genotypes from day 0 up to day 21 post infection though Fulani ecotypes had the highest value at day 21. Lymphocyte counts did not show any significant difference (p>0.05) on day 0 and 3 but there was significant difference (p