Lactic acid bacteria and yeast strains isolated from fermented fish (Budu) identified as candidate ruminant probiotics based on rumen fermentation characteristics.

BACKGROUND AND AIM

Probiotic supplementation can assist with manipulating the rumen microbial ecosystem. Lactic acid bacteria and yeast from fermented fish (Budu) as the indigenous food from West Sumatra, Indonesia, are potential probiotics for livestock. This study aims to select the best candidate lactic acid bacteria and yeast strains from fermented fish as ruminant probiotics and evaluate the effect of their supplementation on the characteristics of rumen fermentation, feed digestion, and total gas production .

MATERIALS AND METHODS

This study used nine treatments, performed in triplicate, in a completely randomized design. The substrate ratio comprised of 70% forage and 30% concentrate. Five lactic acid bacteria and three yeast isolates were used in this study. Treatments were as follows: T0: control (basal diet); T1: T0 + strain 3347; T2: T0 + strain 5296; T3: T0 + JCM 16178; T4: T0 + strain LH991; T5: T0 + strain 6902; T6: T0 + strain B-5P; T7: T0 + strain CBS 5147; and T8: T0 + commercial yeast (). The lactic acid bacteria inoculum contained 1.02 × 10 colony-forming unit (CFU)/mL, while the yeast inoculum contained 1.5 × 10 CFU/mL.

RESULTS

The results showed that four lactic acid bacteria and three yeast produced a higher total gas yield (104-183.33 mL) compared to the control (103 mL). Supplementation with lactic acid bacteria in the rumen fermentation showed dry matter digestibility of 63%-70% and organic matter digestibility (OMD) of 64%-71%. We observed that total volatile fatty acid (VFA) production in all treatments was significantly higher (86-121 mM) compared to the control (81 mM). The concentration of NH production was higher in all treatments (12.33-16.83 mM) than in the control (12.25 mM). Meanwhile, the probiotic supplementation did not cause a significant change in the rumen pH (6.86-7.12). Supplementation with the lactic acid bacteria strain LH991 consistently demonstrated the best results from the parameters of dry and OMD (70.29% and 71.16%, respectively), total VFA (121.67 mM), NH (16.83 mM), and total gas production (149.17 mL). The best results were observed from the yeast candidate strain B-5P, where the results were dry and OMD (67.64% and 69.55% respectively), total VFA (96.67 mM), NH (13.42 mM), and total gas production (183.33 mL).

CONCLUSION

Based on the obtained results, lactic acid bacteria strain LH991 and yeast strain B-5P are attractive candidates to be utilized as probiotics for ruminants based on their potential to improve rumen fermentation . This probiotic supplementation can increase the digestibility of feed ingredients, production of total VFA and NH, and total gas produced.