Changes in rumen fermentation and bacterial profiles after administering as a probiotic.

Background And Aim: is one of the lactic acid bacteria that is often used as probiotics. This study aimed to evaluate the effects of TSD10 as a probiotic on rumen fermentation and microbial population in Ongole breed cattle.

Materials And Methods: This study adopted an experimental crossover design, using three-fistulated Ongole breed cattle. Treatments were as follows: T0, control without probiotic; T1, 10 mL probiotic/day; T2, 20 mL probiotic/day; and T3, 30 mL probiotic/day. The basal diet of the cattle comprised 70% concentrate: 30% elephant grass (). The concentration of probiotic used was 1.8 × 10 colony-forming unit (CFU)/mL.

Results: We observed significantly lower acetate production compared with control (64.12%), the lowest values being in the T3 group (55.53%). Contrarily, propionate production significantly increased from 18.67% (control) to 23.32% (T2). All treatments yielded significantly lower acetate-propionate ratios than control (3.44), with the lowest ratio in the T3 group (2.41). The protozoal number decreased on probiotic supplementation, with the lowest population recorded in the T2 group (5.65 log cells/mL). The population of specific rumen bacteria was estimated using a quantitative polymerase chain reaction. We found that the population of , and , did not change significantly on probiotic supplementation, While that of increased significantly from 9.88 log CFU/mL in controls to 12.62 log CFU/mL in the T2 group.

Conclusion: This study showed that the optimum dosage of TSD10 as a probiotic was 20 mL/day. The effect of as a probiotic on feed degradation in rumen was not evaluated in this experiment. Therefore, the effect of as a probiotic on feed degradation should be performed in further studies.