Mineral Advice in Ruminants: Are we getting it right?

Optimising mineral nutrition can maximise animal performance, but it is a competitive area of the market, and the advice given is often commercially biased or outdated. The objective of this study was to evaluate mineral nutrition in ruminant production and analyse the advice being communicated by professionals on farms. The countries visited included the UK, Brazil, USA, Canada, Germany, Japan, and New Zealand, where farmers, nutritionists, academics, laboratories, specialist consultants, and veterinarians were consulted.

Textbook values for the mineral requirements of ruminants have not remained static since they were first published. These values have evolved as more studies have been conducted and additional evidence about requirements has become available. Despite this, for many minerals, there remains a low level of certainty regarding animal requirements. Minerals can be categorised into three groups: those for which there is extensive data allowing for a defined “requirement”; those with limited data where only an “adequate intake” can be suggested; and those known to be necessary but lacking sufficient quantitative or experimental evidence, instead showing a physiological “response” to dietary changes. Scientific understanding continues to evolve, and numerous on-farm variables can alter the optimum mineral balance for a particular group of animals. Understanding the level of certainty and the factors that can influence mineral formulation is crucial. The complexity is further increased by the wide range of mineral products available, particularly those claiming improved bioavailability, which require careful scrutiny and appropriate data for precise diet formulation. Mineral nutrition should be tailored to each farm system, as a one-size-fits-all approach rarely optimises outcomes.

Measurement, monitoring, and diagnostics—such as analyses of feed, forage, blood, and liver mineral concentrations—should be strategically employed to provide decision-makers with insight into the current nutritional strategy and any potential improvements. Analyses should be conducted in a timely manner, and data should be presented clearly to aid interpretation and always be evaluated in context.

On-farm advice is difficult to assess, but one of the most important yet challenging insights from many conversations was the significance of the phrase “I don’t know.” Farmers often reported receiving incorrect or insufficient information and indicated they would have had greater trust in their advisors had uncertainty been acknowledged. Copper continues to be a contentious issue in dairy nutrition, with cases of toxicity persisting in the industry. The “more is better” approach and competitive feed formulations are barriers to progress. Lessons learned from copper management can inform future efforts to align mineral supplementation with evolving scientific insights, ultimately enhancing animal health and performance.