In vitro gas production kinetics and digestibility of king grass (Pennisetum hybrid) added by organic mineral and natural crude tannin

ABSTRACT

This research was conducted to compare kinetics of gas production, methane emission, and in vitro digestibility between organic mineral (OM) and inorganic mineral (IM) in king grass (Pennisetum hybrid), in combination with natural crude tannin from neem (Azadirachta indica, AI) leaves. Treatments were as follows: T0 (king grass as a control), T1 (T0 + 3% IM), T2 (T0 + 3% OM), T3 (T0 + 2% AI), T4 (T0 + 3% IM + 2% AI), T5 (T0 + 3% OM + 2% AI), and T6 (T0 + 40 ppm monensin), and these were arranged on a completely randomized design. Data were analysed using ANOVA and orthogonal contrast test was used for comparing among treatment means. Results showed that either OM or IM supplementation significantly increased (P < .05) gas production. Total gas productions from T0, T3, T5, and T6 were lower than those of T1, T2, and T4. Total VFA, acetate, and propionate were similar in all treatments; however butyrate concentration was higher in T2 and T4 than the others. In vitro organic matter digestibility, protozoa cells number, and ammonia and methane concentrations were not influenced (P > .05) by treatments. In summary, either OM or IM improved fermentability of king grass while their combination with tannin-containing leaves reduced the fermentability without affecting methane production.

KEYWORDS:

• Digestibility
• gas production
• methane
• organic mineral
• tannin

ORCID

Ahmad Sofyan http://orcid.org/0000-0002-0578-4671

Additional information

Funding

This research was supported by the Indonesian Institute of Sciences (LIPI) through the research project for feed additive thematic program (DIPA:0042/079-01.2.01/14/2012).