Effects Of Cultivation Stages On In Vitro Rumen Digestibility And Fermentation Characteristics Of Sprouted Barley

This study determined the effect of cultivation stages on in vitro rumen digestibility and fermentation characteristics of sprouted barley (SB). The SBs were collected at 0, 4, and 8 days of cultivation stages, dried at 65oC for 48 h, and ground to pass 1-mm screen for the chemical compositions and in vitro incubation. Rumen fluid from two cannulated Hanwoo heifers was mixed with Van Soest medium at 1:2 ratio. The ground SB (0.5 g) was placed into the incubation bottle with the mixture of rumen fluid/Van Soest medium (40 mL) in quadruplicates, and incubated for 0, 1, 2, 4, 8, 24, and 48 h. After incubations, the bottle contents were centrifuged and collected the supernatant for pH, ammonia-N, and volatile fatty acid (VFA), and the residue for in vitro digestibility of dry matter (IVDMD) and neutral detergent fiber (IVNDFD). With increasing cultivation stage, the concentrations of crude protein, ether extract, crude ash, neutral detergent fiber, acid detergent fiber, and hemicellulose of SB increased (L, P<0.05), but decreased dry matter (L, P=0.001), IVDMD (Q, P<0.001), and IVNDFD (Q, P=0.005). The IVDMD and IVNDFD of SB were highest (P<0.05) at 4 day of cultivation. Rumen pH (L, P<0.001), propionate (L, P<0.001), and iso-butyrate (Q, P=0.001) at 48 h incubation of SB increased (L, P<0.001) with increasing cultivation stage, while total VFA (L, P=0.001), acetate (L, P=0.018), butyrate (Q, P=0.01), iso-valerate (L, P=0.001), and acetate to propionate ratio (Q, P<0.001) decreased. During 24 h incubation, SB cultivated for 4 day showed the lowest (P<0.001) rumen pH and the highest (P<0.001) total VFA. Furthermore, it produced the lowest (P<0.001) ammonia-N at 8 h incubation. In conclusion, applied SB at 4 day potentially improved rumen digestibility and fermentation characteristics.