6AAFCO. 1994.Official publication[M]. Association of American Feed Control Officials, Inc. Atlanta, GA.
7Aattouri N, et al. 2002. Oral ingestion lactic - acid bacteria by rats increases lymphocyte proliferation and interferon-γ production[J] . British J ofNutrltion, (4) 367- 373.
8Dawson K A, Newman K A. 1990. Effects of microbial supplements containing yeast and lactobacilli on roughage- fed ruminal microbial activities[J ] .J Anita. Sci. Aug. 68: 3392- 3398.
9Heugten E V, Dorton K L. 2001. Effects of live yeast supplementation on weanling pig performance [ R]. Annal Swine Report, College of agricultures and life sciences,North Carolina State University.
10Indegrrew W M. 1999.Yeast:could you have a business on this bug [ A]. In :Biotechnology in the Feed Induxtry [ C] Nottingham University Press, Loughborough, Leics. UK. Vol. 15 : 27- 50.
