| Summary: | 碩士 === 國立嘉義大學 === 獸醫學系研究所 === 102 === Aavian metapneumovirus (aMPV) causes the swollen head syndrome (SHS) which is an upper respiratory infection. SHS induces growth retard, secondary bacteria infection, and worsens the infection and increases the mortality. Since lacking the SHS related informations of country chicken in Taiwan, this study designed to realize the effects of SHS infection on livability and feed conversion rate (FCR) of country chicken in Taiwan. From May 2012 to February 2013, collected serum and nasal swabs of aMPV unvaccinated country chicken 6 to 13 weeks age among 24 villages and towns specifically in northern, central and southern areas in Taiwan. 614 serum and 640 nasal swabs collected from 32 farms are separately examined by the enzyme-linked immunosorbent assay (ELISA) and the reverse transcription-polymerase chain reaction (RT-PCR) to detect the antibody and aMPV nucleic acids within. The results of ELISA reveal that each farm positive rates are among 0 to 100 %; average positive rate is 44.7 % (274/613); average farm positive rate is 68.7 % (22/32). The positive rate of country chicken of northern area is the hightest of all; 3.65 times than the positive rate of central area; 2.87 times than the positive rate of southern area.The positive rate of 6 weeks age (85.6 %) is the hightest of all, and the positive of 8 weeks age is the lowest of all; the positive rate of 12 weeks age is 100 %. The results of RT-PCR showing the farm positive rates are among 5 to 80 %; farm positive rate is 21.9 % (7/32); average positive rate is 6.56 % (42/640) entire is B type, and the livability is among 75.2 % to 82.3 %. Separate the farms into positive (positive rate > 10 % ) and negative group (positive rate < 10 %), and caulate the p value of Livability and FCR. The p value of livability is 0.04 (p < 0.05) and the p value of FCR is 0.01 (p < 0.01) all obiviously lowers than negative group. In conclusion, the aMPV infection of country chicken is widespread and easily causes secondary infection which significant influence the livability and FCR.
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