Effect of a direct-fed microbial on plasma concentrations of hormones and metabolites in primiparous and multiparous Holstein cows

This study was conducted to evaluate the effect of supplemental feeding Propionibacterium P169 on key metabolic indicators in lactating cows.; Plasma glucose concentrations were affected by diet x parity such that plasma glucose in low-dose P169 multiparous cows (59.8 +/- 1.1 mg/dL) were 5.5% lower than in high-dose P169 multiparous cows; low-dose P169 primiparous cows (67.9 +/- 0.9 mg/dL) had 6% to 9% greater plasma glucose concentrations than high-dose P169 and Control primiparous cows. Plasma insulin concentrations were affected by diet such that low-dose P169 had less plasma insulin than high-dose P169 and Control cows (during wk 13--25), and high-dose P169 cows had greater insulin than Controls (during wk 1--12). Regardless of parity, low-dose P169 cows had greater leptin concentrations than Controls cows, and high-dose P169 cows had greater plasma NEFA than Control cows. We conclude that P169 may hold potential as a direct-fed microbial to enhance metabolic efficiency during early and mid-lactation. (Abstract shortened by UMI.)...