A Re-evaluation of the Optimal Liver Copper Concentrations for Health, Performance and Fertility of Replacement Holstein-Friesian Heifers.

ABSTRACT: Excessive copper (Cu) supplementation is common on dairy farms worldwide, despite a growing body of research highlighting the risks of over-supplementation, including liver damage, impaired growth, and reduced fertility. However, diagnosing Cu toxicity remains challenging due to the liver's allostatic regulation of blood Cu levels and debate surrounding toxicity thresholds. This study utilised secondary data from a longitudinal study conducted between September 2016 and September 2018 involving 80 replacement Holstein-Friesian heifers. Data was utilised to generate receiver operating characteristic curves which established liver Cu thresholds associated with suboptimal liver function and fertility. Results indicated that hepatic Cu concentrations exceeding 167 mg/kg of dry matter (DM) were

SUBMITTER: Marsh AP 

PROVIDER: S-EPMC12847115 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature