Changes in ruminal fermentable characteristics and nutrient degradabilities of corn flake according to chamber type in Hanwoo: chamber type for corn flake in the rumen of Hanwoo

This study was conducted to investigate the effect of a steam chamber type on the ruminal fermentable characteristics and nutrient degradabilities of corn flakes in Hanwoo. Three Hanwoo equipped with a ruminal fistula were used as experimental animals. There were two treatments: Corn flake using a steam chamber (CFSC, 1.0 atm - $100^{\circ}C$ 96 min) or corn flake using a pressurized steam chamber (CFPSC, 1.5 atm - $111^{\circ}C$ 12 min), respectively. In the in vitro trial, the ruminal pH was significantly lower in the CFPSC than in the CFSC (p < 0.01). The ammonia concentration was increased by 14.1% in the CFPSC compared to the CFSC (p < 0.05). The concentration of acetic acid was higher in the CFSC than in the CFPSC (p < 0.01). The concentrations of propionate, butyrate and total-VFA at 24 and 48 h were higher in the CFPSC than in the CFSC (p < 0.05). In the in situ trial, the degradability of dry matter was significantly higher in the CFSC than in the CFSC (p < 0.01). In addition, the degradabilities of starch and crude protein were significantly higher in the CFSC than in the CFSC (p < 0.01). Thus, the present results indicate that the pressurized steam chamber could be recommended to improve the feed value of corn flake according to the increase in the starch degradability and volatile fatty acid production.