Reducing the risk of copper toxicity in dairy cattle
NEITHER Grace and Knowles (2015) nor Kendall and others (2015) mentioned the underlying reason for the upsurge in bovine copper toxicity: ignorance of how well copper is absorbed from mixed rations. Advice in the small print of ARC (1980) gave requirements for ruminants that ranged from 5 to 20 mg Cu/kg dry matter (DM) a concept that does not remotely tally with a consensus requirement of 8 to 11 mg Cu/kg DM (Sinclair and Atkins 2015) Supporting evidence came from, arguably, the wrong species (sheep) on irrelevant (semi purified) diets, but later studies from the UK and New
Veterinary Record