2Dritz S S,Tokach M D,Goodband R D,et al. Effects of administration of antimicrobials in feed on growth rate and feed efficiency of pigs in multisite production sys- tems. Amvetmed Assoc. ,2002,220 (11) : 1690 - 1695.
3Gaskins H R, Collier C T, Anderson D B. Antibiotics as growth promotants : mode of action. Anim. Biotech- nol. , 2002 (13) : 29 - 42.
4Zimmerman D R. Role of subtherapeutiel evels of an- timicrobrals in pig production. Anim. Sei., 1986 (62) :6 - 17.
6Sugita H, Hirose Y, Matsuo N, et al. Production of the antibacterial substance by Bacillus sp Strain NM 12, an instestinal bacterium of Japanese coastal fish. Aquaculture, 1998,165 (3 - 4) :269 - 280.
10Kerovuo J, Lauraeus M, Nurminen P, et al. Isola- tion, characteriantion, molecular gene cloning, and sequencing of a novel phytase from Bacillus subti- lis. Applied and Environmental Microbiology, 1998,64(6) :2079 - 2085.