Efficiency of feed and energy use in primiparous and multiparous dairy cows fed contrasting dietary protein concentrations across lactation.

ABSTRACT: Reducing dietary CP concentration can reduce feeding costs and N excretion in dairy production but may negatively impact productivity and efficiency. This study investigated the impact of reduced dietary CP concentration, across early, mid- and late-lactation stages in primiparous and multiparous lactating cows, on productivity, feed and energy use efficiency and CH₄ emission parameters. Twenty-four Holstein-Friesian (12 primiparous, 12 multiparous) cows were allocated to three experimental total mixed rations containing 12.2, 15.1 or 18.1% CP (LCP, MCP and HCP, respectively; DM basis), in a continuous study across lactation (days 1-305). Digestibility and gas exchanges were measured in metabolism units and indirect open-circuit respiration calorimeter chambers during early, mid

SUBMITTER: Ormston S 

PROVIDER: S-EPMC11904127 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature