The Effects of a Fermentation Product by Aspergillus oryzae on the in vitro Digestibilities of Dry Matter, Fiber and Protein and pH in the Fermentation Fluid of Diets for Dairy Cows

착유우 사료에 대한 Aspergillus oryzae 발효물질 첨가가 in vitro 건물, 섬유소 및 단백질 소화율과 발효액의 pH에 미치는 영향

  • Myung, Yoon-Ah (Dept. of Animal Sci. and Res. Coll of Agri. and Life Sci. Chungnam Nat'l Univ.) ;
  • Park, Duk-Sub (Woosung Feed Co., Ltd.) ;
  • Lee, Soo-Kee (Dept. of Animal Sci. and Res. Coll of Agri. and Life Sci. Chungnam Nat'l Univ.) ;
  • Park, Jong-Soo (Dept. of Animal Sci. and Res. Coll of Agri. and Life Sci. Chungnam Nat'l Univ.) ;
  • Kim, Yong-Kook (Dept. of Animal Sci. and Res. Coll of Agri. and Life Sci. Chungnam Nat'l Univ.)
  • 명윤아 (충남대학교 농업생명과학대학 동물자원학부) ;
  • 박덕섭 ((주) 우성사료) ;
  • 이수기 (충남대학교 농업생명과학대학 동물자원학부) ;
  • 박종수 (충남대학교 농업생명과학대학 동물자원학부) ;
  • 김용국 (충남대학교 농업생명과학대학 동물자원학부)
  • Published : 2002.12.31

Abstract

This study was conducted to examine the effects of an Aspergillus oryzae fermentation culture on the in vitro digestibilities of dry matter, crude fiber, acid detergent fiber (ADF), neutral detergent fiber (NDF), crude protein, and pH in in vitro experiment of diets for dairy cows. A fungal species, Aspergillus oryzae was supplied by Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea (KCTC 1229). The experimental diets were commercial compound feed (concentrate) and total mixed ration (TMR) for lactating cows, of which chemical analyses were determined at Research and Development Institute, Woosung Feed Co., Ltd., while the digestibilities were done at the laboratory of Chungnam National University. Aspergillus oryzae culture products were added to compound feed and TMR at the rate of 0, 1.0, 2.0, 3.0% respectively. The experimental diet with the rumen fluid sampled from Holstein fresian milking cows were used and digested for 24 hrs, 48hrs and 72hrs in the shaking incubator. The residues of the digesta were digested for 48hrs in the incubator in which put 30ml of 0.1N HCl with 0.2% pepsin at $39^{\circ}C$. The final precipitates were dried for 48hrs in the drier at $60^{\circ}C$. These experimental procedures were triplicated to determine the in vitro digestibility of dry matter, crude fiber, ADF, NDF, crude protein and pH. Compared to control diet, not added Aspergillus oryzae, the DM digestibility of fungal diets were improved 2.1%(63.1%), 9.7%(68.5%) and 9.0%(68.0%) for 24 hour fermentation in compound feed while 4.8%(60.0%), 6.4%(61.1%) and 2.9%(58.8%) in TMR. On the contrary, for 48 hour and 72 hour digestibilities, the effects of Aspergillus oryzae culture on the digestibility of dry matter were relatively lowered compared to 24 hour digestibility. Referring to the digestibility of dietary fiber, Aspergillus oryzae was believed to significantly improve digestibilities of crude fiber, ADF and NDF. Those were increased up to 13.3%(53.3%) for 24 hour fermentation, while 2.4%(54.6%) for 3.0% added for 72 hour fermentation in compound feed. However, there were no significant differences among the treatments for the inclusion rate of Aspergillus oryzae, even though the more inclusion rate, the better digestibility. The protein digestibilities were significantly improved from 0.4%(79.7%) to 9.4%(71.8%) by adding Aspergillus oryzae into compound feed. However, there were no significant differences between the two experimental diets, 2.0% and 3.0% Aspergillus oryzae included diets. In case of TMR, the protein digestibilities were significantly improved from 4.0%(70.4%) to 6.3%(65.1%) by adding Aspergillus oryzae. However, there were no significant differences between the two experimental diets, 2.0% and 3.0% Aspergillus oryzae included diets. In this study, there were no significant differences among the treatments in pH. On the contrary, there were slightly decrease in pH by adding Aspergillus oryzae into experimental diets but not significant. Summarizing the results of this examination, Aspergillus oryzae fermentation culture is believed to improve the digestibilities of dry matter, fiber and crude protein in cattle diets. However, more detailed research for the mechanism of the fungal culture is required to improve ruminal environment.

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