Gas production kinetic and organic matter digestibility in vitro of diet supplemented by biochar and liquid smoke

Abstract

Abstract This research aimed to evaluate the use of biochar and liquid smoke as feed additives on gas production and organic matter digestibility of a complete feed in the in vitro rumen fermentation system. Biochar and liquid smoke came from the pyrolysis process of cacao pod husks. Treatments consisted of: control (substrate), biochar BC1 (0.1 mg / ml), BC2 (0.2 mg / ml), BC3 (0.3 mg / ml), BC4 (0.4 mg / ml), liquid smoke LS1 (0.25 ul / ml), LS2 (0.5 ul / ml), LS3 (0.75 ul / ml) and LS4 (1.0 ul / ml). The samples were incubated in vitro with buffered-rumen fluid in four replicates, represented by two incubation units per replicate, and conducted for 48 h at 39oC. Parameters measured in the in vitro evaluation were total gas production and digestibility of organic matter. Data were tested using analysis of variance (ANOVA) and if there was a significant difference at P<0.05 then continued with Duncan’s multiple range test. The results showed that supplementation of biochar and liquid smoke did not affect gas production. However, the addition of biochar and liquid smoke decreased the digestibility of dry matter and organic matter as compared to a control substrate (P <0.05). Furthermore, the addition of biochar and smoke caused a decrease in total protozoa (p<0.05). It was concluded that biochar supplementation and liquid smoke as feed additive reduce protozoa without affecting total gas production and gas production rate.