| Summary: | 碩士 === 國立嘉義大學 === 獸醫學系研究所 === 103 === Chicken infectious anemia (CIA) is one of the most important inmmuno-suppressive diseases that cause anemia in poultry. This study detected the CIA antibody titers before slaughter and analyzed with their production efficiency from 24 broiler flocks in Yun-Chia-Nan areas in Taiwan. Another trial was to detect the lymphoid organs and body weight ratio, hematocrit, serum CAV antibody titers, PCR and histopathological test in different ages from 4 consecutive batches in the same commercial broiler flock. The flock positive rate of CIA antibody before slaughter was 79.16 % (19/24), the individual positive rate was 41.56 % (160/385), and the prevalence range was 17.85-63.19 %. Analysis showed that the correlation coefficient (r value) between antibody mean titer and product index is 0.39, which revealed a low linear relationship. Althought house system didn’t effect the antibody mean titer, the production efficiency of water pad house groups was significantly better than traditional house groups. Two flocks from different parental flocks' progeny that were in the same farm, rearing period, feeding condition, the production index of the higher CIA antibody posistive rate batch frequently would more inferior than the lower one. Besides, the disparities of their feeding costs were among 0.7 to 10.7 NTD per broiler. Analyzed vaccination index and production index of the CAV maternal antibody about 4 batches in 1 day-old broilers, and the r value was 0.62 that revealed significant relationship. Due to maternal antibody decrease that can not afford to protect broiler against CIA, infection may occur and produce pathological lesions in 15 day-old. It seems that the high level of CIA maternal antibody, which induced from broiler breeder, increased production efficiency in their progeny. Therefore, vaccination to broiler breeder is be recommended. This study provided the immunological parameters in differnent ages of broilers and revealed that maternal antibody dropped in 2-4 weeks and then seroconversion at the 5th week. Biosecurity should be carried out cautiously to avoid wild strain infection.
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