Almirall, M., M. Francesch, A. M. Perez-Vendrell, B. J. Esteve-Garcia and Enric. 1995. The differences in intestinal viscosity produced by barley and beta-glucanase alter digesta enzyme activities and ileal nutrient digestibilities more in broiler chicks than in cocks. J. Nutr. 125:947-955.
AOAC. 1990. Official Methods of Analysis,10th Edition. AOAC, Washington, DC.
Bi Yu and T. K. Chung. 2004. Effects of multiple-enzyme mixture on growth performance of broilers fed corn-soybean meal diets. J. Appl. Poult. Res.13:178-182.
Borg, B. S., G. W. Libal and R. C. Wahlstom. 1987. Tryptophan and threonine requirements of young pigs and their effects on serum calcium, phosphorous and zinc concentrations. J. Anim. Sci. 64:1070-1078.
Brenes, A., M. Smith, W. Guenter and R. R. Marquardt. 1993. Effect of enzyme supplementation on the performance and dige-stive tract size of broiler chickens fed wheat- and barleybased diets. Poult. Sci. 72:1731-1739.
Brenes, A., R. R. Marquardt, W. Guenter and A. Viveros. 2002. Effect of enzyme addition on the performance and gastrointestinal tract size of chicks fed lupin seed and their factions. Poult. Sci. 81:670-678.
Burnett, G. S. 1966. The effect of damaged starch, amylolytic enzymes, and proteolytic enzymes on the utilization of cereals by chickens. Br. Poult. Sci. 3:89-103.
Cafe, M. B., C. A. Borges, C. A. Fritts and P. W. Waldroup. 2002. Avizyme improves performance of broilers fed corn-soybean meal-based diets. J. Appl. Poult. Res. 11:29-33.
Cowieson, A. J., T. Acamovic and M. R. Bedford. 2003. Supplementation of diets containing pea meal with exogenous enzym-es: Effects on weight gain, feed conversion, nutrient digestibility and gross morphology of the gastrointestinal tract of growing broiler chicks. Br. Poult. Sci. 44: 427-437.
Friesen, O. D., W. Guenter, R. R. Marquardt and B. A. Rotter. 1992. The effect of enzyme supplementation on the apparent met-abolizable energy and nutrient digestibility of wheat, barley, oat and rye for the young broiler chick. Poult. Sci. 73:1710-1721.
Fry, R. E., J. B. Allred, L. S. Jensen and J. P. McGinnis. 1958. Influence of enzyme supplementation and water treatment on the nutritional value of different grains for poults. Poult. Sci. 37:372-375.
Gracia, M. I., M. J. Araníbar, R. Lazaro, P. Medel and G. G. Mateos. 2003. $\alpha$-Amylase supplementation of broiler diets based on corn. Poult. Sci. 82:436-442.
Iji, P. A., R. J. Hughes, M. Choct and D. R. Tivey. 2001. Intestinal structure and function of broiler chickens on wheat-based diets supplemented with a microbial enzyme. Asian-Aust. J. Anim. Sci. 14:54-60.
Inborr, J. 1990. Enzymes in animal feeding. Milling. 2:28-34.
Jaroni, D., S. E. Scheideler and C. Wyatt. 1999. The effect of dietary wheat middlings and enzyme supplementation. II: apparent nutrient digestibility, digestive tract size, gut viscosity and gut morphology in two strains of Leghorn hens. Poult. Sci. 78:1664-1674.
Kocher, A., M. Chot, G. Ross, J. Broz and T. K. Chung. 2003. Effects of enzyme combinations on apparent metabolizable energy of corn-soybean meal-based diets in broilers. J. Appl. Poult. Res. 12:275-283.
Lazaro, R., M. A. Latorre, P. Medel, M. Gracia and G. G. Mateos. 2004. Feeding regimen and enzyme supplementation to ryebased diets for broilers. Poult. Sci. 83:152-160.
Lowry, O. H., N. R. Rosebrough, A. L. Farr and R. J. Randall. 1951. Protein measurement with the Folin phenol reagent. J. Biol. Chem. 193:265-275.
Mahagna, M., I. Nir, M. Larbier and Z. Nitsan. 1995. Effect of age and exogenous amylase and protease on development of the digestive tract, pancreatic enzyme activities and digestibility of nutrients in young meat-type chicks. Reprod. Nutr. Dev. 35: 201-212.
Marquardt, R. R., A. T. Ward and R. Misir. 1979. The retention of nutrients by chicks fed rye diets supplemented with amino acids and penicillin. Poult. Sci. 58:631-639.
Ni, Z. Y. 2000. Influence of enzyme complex on performance and nutrient availability of broilers. Thesis for Masters Degree Sichuan Agricultural University. Ya'an, Sichuan, China.
NRC. 1994. Nutrient Requirements of Poultry. 9th rev. ed. National Academy Press, Washington, DC.
Onderci, M., N. Sahin, K. Sahin, G. Cikim, A. Aydín, I. Ozercan and S. Aydín. 2006. Efficacy of supplementation of $\alpha$-amylaseproducing bacterial culture on the performance, nutrient use, and gut morphology of broiler chicken fed a corn-based diet. Poult. Sci. 85:505-510.
Pack, M. and M. R. Bedford. 1997. Feed enzymes for cornsoybean broiler diets. World Poult. 13:87-93.
Pack, M., M. R. Bedford and C. Wyatt. 1998. Feed enzymes may improve corn, sorghum diet. Feedstuffs 2 (Feb.):18-19.
Rotter, B. A., A. A. Frohlich, R. C. Rotter and R. R. Marquardt. 1989. Estimation of the apparent protein digestibility using uric acid corrected nitrogen values in poultry excreta. Poult. Sci. 68:327-329.
Sarmiento-Franco, L., J. M. McNab, A. Pearson and R. Belmar-Casso. 2003. The effects of chaya leaf meal and of exogenous enzymes on amino acid digestibility in broilers. Br. Poult. Sci. 44:458-463.
SAS Institute. 1996. SAS User's Guide: Statistics. Version 7.0. SAS Institute, Cary, NC.
Scheideler, S. E., M. M. Beck, A. Abudabos and C. L. Wyatt. 2005. Multiple-enzyme (avizyme) supplementation of corn-soybased layer diets. J. Appl. Poult. Res. 14:77-86.
Silva, S. S. P. and R. R. Smithard. 2002. Effect of enzyme supplementation of a rye-based diet on xylanase activity in the small intestine of broilers, on intestinal crypt cell proliferation and on nutrient digestibility and growth performance of the birds. Br. Poult. Sci. 43:274-282.
Wang, H. T. and J. T. Hsu. 2006. Usage of enzyme substrate to protect the activities of cellulose, protease and $\alpha$-amylase in simulations of monogastric animal and avian sequential total tract digestion. Asian-Aust. J. Anim. Sci. 19:1164-1173.
Wang, Z. R., S. Y. Qiao, W. Q. Lu and D. F. Li. 2005. Effects of enzyme supplementation on performance, nutrients digestibility, gastrointestinal morphology, and volatile fatty acid profiles in the hindgut of broilers fed wheat-based diets. Poult. Sci. 84:875-881.
Zanella, I., N. K. Sakomura, F. G. Silversides, A. Fiqueirdo and M. Pack. 1999. Effect of enzyme supplementation of broiler diets based on corn and soybeans. Poult. Sci. 78:561-568.
Zhengyu Jiang, Yanmin Zhou, Fuzeng Lu, Zhaoyu Han and Tian Wang. 2008. Effects of different levels of supplementary alpha-amylase on digestive enzyme activities and pancreatic amylase mRNA expression of young broilers. Asian-Aust. J. Anim. Sci. 21:97-102.