Application of lactic acid bacteria producing antifungal substance and carboxylesterase on whole crop rice silage with different dry matter

Objective:This study was conducted to investigate effects of antifungal substance and carboxylesterase-producing inoculant on fermentation indices and rumen degradation
kinetics of whole crop rice (WCR) silage ensiled at different dry matter (DM) contents.

Methods:Dual-purpose inoculants, Lactobacillus brevis5M2 and Lactobacillus buchneri 6M1, confirmed both activities of antifungal and carboxylesterase in the previous study.
The WCR at mature stage was chopped, and then wilted to obtain three different DM contents consisting of 35.4%, 43.6%, and 51.5%. All WCR forages were applied distilled
water (CON) or mixed inoculants with 1:1 ratio at 1×10
5 colony forming unit/g (INO), and ensiled into 20 L mini silo (5 kg) in quadruplicates for 108 d.

Results:The INO silages had lower lactate (p<0.001) and butyrate (p = 0.022) with higher acetate (p<0.001) and propionate (p<0.001) than those of CON silages. Ammonia-N
(p<0.001), lactate (tendency; p = 0.068), acetate (p = 0.030), and butyrate (p<0.001) concentrations of INO silages decreased linearly with increasing DM content of WCR forage.
The INO silages presented higher lactic acid bacteria (p<0.001) with lower molds (p< 0.001) than those of CON silages. Yeasts (p = 0.042) and molds (p = 0.046) of WCR
silages decreased linearly with increasing DM content of WCR forage. In the rumen, INO silages had higher the total degradable fraction (p<0.001), total volatile fatty acid
(tendency; p = 0.097), and acetate (p = 0.007), but lower the fractional degradation rate (p = 0.011) and propionate (p<0.001) than those of CON silage. The total degradable
fraction (p<0.001), total volatile fatty acid (p = 0.001), iso-butyrate (p = 0.036), and valerate (p = 0.008) decreased linearly with increasing DM content of WCR forage, while the
lag phase (p<0.001) was increased linearly.

Conclusion:This study concluded that application of dual-purpose inoculants on WCR silage confirmed antifungal and carboxylesterase activities by inhibiting mold and improving
rumen digestibility, while increase of wilting times decreased organic acids production and rumen digestibility.