張伸彰 涂海南 許晉賓 吳明哲 張秀鑾
DEVELOPMENT OF PROLIFIC LINE IN SWINE III.
TRAITS IN F3 OF MEISHAN AND DUROC CROSSES
S. C. Chang, H. N. Twu, C.B. Hsu, M. C. Wu and H. L. Chang
Taiwan Livestock Research Institute, Council of Agriculture
The objective of this study was to evaluate the growth performances of F3 generation in Meishan (M) and Duroc (D) crosses pigs for selection reference. Pigs evaluated including progeny of F2, expressed as md and dm for MDMD and MDDM, respectively, which were obtained from intercrossing of M and D crosses. There were four groups of F3 pigs tested which mdmd, mddm, dmmd and dmdm being the progeny of md sows sired by md boars, md sows sired by dm boars, md sows sired by dm boars and dm sows sired by dm boars, respectively. A total of 202 boars and 326 gilts were growth performances tested during 70 an 210 days of age, which including 50 boars and 87 gilts of mdmd, 48 boars and 72 gilts of mddm, 52 boars and 64 gilts of dmmd, and 52 boars and 86 gilts of dmdm crosses, respectively. Traits evaluated were body weights at 70 (W70), 90 (W90), 120 (W120), 150 (W150), 180 (W180) and 210 (W210) days of age, and averaged backfat thickness at 150 (BF150), 180 (BF180) and 210 (BF210) days of age which were measured at 5 cm from dorsal line of the fifth and the last ribs, as well as the last lumbar. Boars were tested individually and the corresponding feed efficiency during testing period was also evaluated. Since gilts were group housed, feed consumed information was lacked. Result showed that mdmd gilts weighed heavier at 180 and 210 days of age than those of mddm and dmdm gilts (P<0.001). Significant thinner backfat measures at 180 and 210 days of age were found in dmdm gilts than those of obtained from mdmd and dmmd gilts（P<0.01）. Furthermore, mdmd boars had thicker backfat at 180 and 210 days of age than those measured in mddm and dmdm pigs (P<0.01). Similar trend also observed at body weight at 210 days of age (P<0.05).
Key Words: Meishan pigs, Duroc pigs, Growth performances.