Effect of Feed Supplement on In vitro Gas Production, Substrate Degradation and Efficiency of Microbial Biomass Production

Abstract

The present study was conducted to ascertain the efficacy of a special feed supplement (SFS) in the ration of dairy animals by in vitro gas production technique (IVGPT). For this, four substrates viz., wheat straw, SFS, the composite diet typically used by dairy farmers (control; CON) and a combination of the CON and SFS (TREAT) were studied for in vitro fermentation kinetics and substrate degradation. The total gas volume (mL/200 mg) produced after 24 h of incubation was significantly (P<0.01) higher for SFS as compared to CON, TREAT and wheat straw. The microbial biomass production (MBP, mg/200 mg), the efficiency of microbial biomass production (EMP,%TDOMR) and partitioning factor (PF) were found to be significantly (P<0.01) higher in SFS as compared to TREAT, CON and wheat straw. The fortification of CON diet with the SFS significantly (P<0.01) increased the MBP, EMP and PF as compared to CON. The cumulative gas production at different hours of incubation was significantly (P<0.05) higher in SFS followed by TREAT, CON and wheat straw. The addition of the SFS to CON diet had significantly (P<0.05) increased the cumulative gas production. The potential gas production (b) was significantly (P<0.05) higher for SFS as compared to other substrates; however, the inclusion of SFS to CON diet led to significantly (P<0.05) higher potential gas production as compared to CON and wheat straw. The fractional rate of fermentation (c) was also found to be significantly (P<0.05) higher in SFS followed by TREAT, CON and wheat straw. Furthermore, the addition of SFS to CON diet had significantly (P<0.05) reduced gas production at half time (t½) as compared to CON. Thus, it can be concluded that inclusion of the special feed supplement to CON significantly improved the fractional rate of fermentation ‘c’, TDOMR, MBP, EMP and PF. Furthermore, it reduced the half time (t½) of asymptotic gas production. © 2020. All Rights Reserved.