A Genetic Research for Growth and Immune Traits of Reciprocal Crosses between Strains of Taiwan Country Chicken and Rhode Island Red

• Main Authors: Shih-Wen Wu, 吳詩雯
• Other Authors: 李淵百
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/54134794055173051705

碩士 === 國立中興大學 === 動物科學系所 === 99 === Since 19th century, animal breeder have put great effort to create many excellent breeds, and after 1950’s, crossbreeding has been used in commercial poultry production. The important reasons in genetics for crossbreeding is breed complementarity and heterosis. The aim of this study was to investigate the reciprocal crosses between Taiwan Country chicken (L2 strain) and a selected Rhode Island Red strain for low residual feed consumption (R- strain) and study the genetic mechanism of the growth performance and immune traits of their offspring. The result showed that L2 strain has higher body weight (BW), comb area (CA), and shank length (SL) than R- strain. The reciprocal crosses found that the heterosis was an important source of variation in BW from 4 to 16 wk for chickens from both crosses. The percentage of heterosis at the various ages ranged for males and females were 10.0~18.5% and 5.9~11.9%, respectively. Maternal effect was significant for the BW at 0 wk, and the sex-linked was significant for the body weight from 8 to 16 wk. The crossbred males showed highly significant heterosis at 8 and 16 wk in CA estimated as 39.7 and 18.9%, respectively. Significant heterosis was also found for SL at 8 and 16 wk for the males and females estimated as 6.3~6.9% and 4.2~6.2%, respectively. For immune performance, L2 strain had better antibody consistency to newcastle disease and infectious brontitis vaccines and 7 d post vaccination primary response to sheep reed blood cell (SRBC) at 8 wk than R- strain. No significant heterosis was found for the immune response to SRBC in males (－6.6～10.3％). Though significant heterosis was found at 7 d postprimary immunization to SRBC antigen in females (32.8%). There was no significant heterosis at postsecondary immunization to SRBC antigen in both sexes. In conclusion, heterosis was an important source of variation in growth performance of reciprocal crosses between L2 and R- strains, and body weight was affected by maternal effect and sex chromosome, but heterosis was less important source for immune performance.