Maria Mauritsia Lis Sinarti Pengarang NOVALINO HAROLD GEOFFREY KALLAU Dosen Pembimbing 2 ANNYTHA INA ROHI DETHA Dosen Pembimbing 1 Novalino Harold Geoffrey Kallau Penguji 2 Larry Richard Wellem Toha Ketua Penguji Annytha Ina Rohi Detha Penguji 1

Toxoplasmosis is one of the zoonotic diseases caused by the protozoan Toxoplasma gondii (T. gondii) and can infect humans, various types of mammals, and other warm-blooded animals. Cats are the definitive host, and warm-blooded animals such as poultry, in this case, chickens, are the intermediate hosts. Transmission to humans can occur due to consuming cysts found in raw or undercooked chicken meat. This study aimed to determine the level of seroprevalence of T. gondii in free-range and broiler chickens in Kupang City and the relationship between racial risk factors and the incidence of toxoplasmosis. Samples were taken from 7 Poultry Slaughterhouses in Kupang City with a systematic random sampling technique for 11 days. The serological examination was tested using the Red To-MAT kit at the Lampung Veterinary Center. The number of samples used in this study was 15 free-range chicken serum samples and 15 broiler chicken serum samples. The test results show that the seroprevalence value in free-range chickens is 80% (12/15) and broiler chickens 67% (10/15), and the results of the Odds Ratio calculation show a value of 0.5 which means that free-range chickens are 0.5x more susceptible to infection by T. gondii than broiler chickens and a significance value of P>0.05 which means that there is no significant difference in the incidence of T. gondii in chickens in Kupang City. Based on its seroprevalence value, it shows that free-range chickens are more susceptible to infection by T. gondii than broiler chickens, this could be influenced by differences in chicken rearing management. In addition, the high seroprevalence value is caused by the climate and temperature of Kupang City, which supports the sustainability of the life cycle of T. gondii. Keywords: Toxoplasma gondii, seroprevalence, Odds Ratio, free-range chicken, broiler chicken.