Antimicrobial supplementation alters digestibility and ruminal fermentation in a continuous culture model

A dual-flow continuous culture system was used to evaluate the effects of laidlomycin propionate and bacitracin zinc on fermentation, nutrient digestibility, microbial efficiency. Factors were (LP; 2 mg/L volume) (BAC; 1.4 mg/L), treatments as follows: (1) no BAC or LP (CON), (2) without (LP), (3) (BAC), (4) (LP/BAC). fifth treatment supplemented with monensin sodium (MON; 6 mg/L) act a positive control. Both LP/BAC had significantly greater pH than MON (P < 0.05). Antibiotic did not affect NH 3-N concentration = 0.62), but influence total VFA production 0.02). Monensin fermenters proportion 0.05), improved by 7.2% compared CON. Laidlomycin suppressed both acetate 0.01) butyrate further reduced when fed in combination 0.01). numerically acetate:propionate ratio 0.12). These results suggest that may produce ionophore-like vitro.