The use of sustainable livestock feed additives is growing, driven by advances in animal nutrition science, and growing regulatory scrutiny, for example around antibiotic use in agriculture, and methane emissions.

We summarise key relevant markets as digestive health; animal health in general; ruminant burp suppressants to reduce emissions of the greenhouse gas methane; and antibiotic alternatives (see our Chart of the Week, above).

Natural, bioactive animal feed products can be classified according to: probiotics, prebiotics, enzymes, seaweed-based products, and phytogenics, which we describe briefly as follows:

• Probiotics are live microorganisms that improve digestion and immune function. They add to the gut microbiome’s ability to digest fibres, and improve the absorption of nutrients. An example of a company we follow is Locus Fermentation.

• Prebiotics are non-digestible fibres that promote the growth of beneficial gut bacteria. They may reduce the need for antibiotics by improving gut health and supporting the animal’s natural immune system. An example of a company we follow is Biorigin.

• Enzymes such as phytases and proteases break down indigestible nutritional components in feed, making them more bioavailable. This improves digestion and may help reduce gastrointestinal diseases. By potentially lowering the need for antibiotics, such additives can help cut the risk of antibiotic resistance and reduce contamination of soil and water by antibiotic residues. Examples of companies we follow include Agrivida and Biogenic.

• Seaweed-based additives contain bioactive compounds including antioxidants, vitamins, and minerals, that may improve immunity, reduce inflammation, and promote gut health. One high-interest area is the use of seaweed also to reduce methane emissions by ruminant livestock, by incorporating seaweed species such as Asparagopsis into feed. These additives inhibit the production of methane during digestion, offering a possible solution to one of the most pressing pollutants associated with animal farming. Examples of companies we follow include Sea6 Energy and FutureFeed.

• Phytogenic feed additives are derived from herbs, spices, and essential oils, and have antimicrobial, antioxidant, and anti-inflammatory properties. They support animal health by improving the gut microbiota, and reducing harmful bacteria. An example of a company we follow is Phytobiotics.

The regulatory framework for livestock feed additives varies across regions, with an increasing focus on the need for scientific validation and safety assessments, particularly for natural and novel additives.

In the United States, the Food and Drug Administration (FDA) oversees the approval of feed additives. Additives intended to replace antibiotics, such as probiotics and enzymes, must be classified as GRAS (Generally Recognized as Safe). Companies like Cargill and Novozymes have received GRAS status for their additives, enabling them to market these solutions as safe, effective alternatives to antibiotics.

In the European Union, the European Food Safety Authority (EFSA) regulates feed additives under the Feed Additives Regulation. Additives that are considered “novel” require a comprehensive safety evaluation before being approved for use. Seaweed-based products, especially those aimed at reducing methane emissions, fall under this category and are subject to detailed scientific assessments.

In Australia and New Zealand, the region’s regulatory body, Food Standards Australia New Zealand, is currently reviewing applications for novel feed additives, including probiotics and seaweed-derived products.