ARTICLE 64 FEED & ADDITIVE MAGAZINE August 2023 80% reduction with high energy diets and 50-60% reduction for high forage diets. A study looking at the use of bioactive compounds and extracts from garlic and citrus in dairy cow feed at 15g a day found a 23% reduction after 12 weeks, but more work is needed.6 A study looking at increasing inclusion levels of grape pumice, a byproduct of wine production, is in progress. Based on differing modes of actions, it has been noted that supplementing multiple feed additives such as IntelliBond trace minerals – shown to have a 2% reduction - and another feed additive such as 3NOP may achieve up to a 14% reduction in the cow’s carbon footprint. The additive 3NOP (Bovaer) also has been generating positive results, reducing methane emissions by more than 30% (12% reduction in the cow’s carbon footprint) when fed to dairy cows.7 It has been given regulatory approval for use in Europe and several other countries, but is not available in the U.S. NEWER RESEARCH, ONGOING CHALLENGES Several projects studying methane reduction strategies remain in progress or have been proposed. For example, a project with UC Berkley and UC San Francisco now in its early stages looks at using CRISPR technology to engineer gut microbes to reduce methane production, which would optimize the microbiome. Another area for future research is improving the genetic selection of dairy cows following the success seen in New Zealand with sheep. Methane production by individual cows is a heritable trait. Lower emissions could be used as a selection point for producers, providing the industry with a long-term result potentially lowering overall methane generation by 11-26%.8 One challenge for research into methane production is that additive use relies on animals being housed within confined pens – as with dairy herds. Efforts are ongoing to find ways to apply products to cows on pasture. A trial is ongoing with rangeland cattle in Montana, but results are not yet available. Regulations play a role in strategies for reducing methane emissions, with additive registration continuing to be an issue in the U.S. The FDA classifies any additive that creates a change in emissions as something that is changing the structure and function of animals, making it a drug – including additives like 3NOP. An ongoing legislative effort seeks to redefine certain additives as food additives and not drugs. The proposed amendment would reclassify any product added to the food or water of production animals and acts within the GI tract to alter emissions or waste, reduce foodborne pathogens, alter the microbiome, or affect the structure and/or function. LEVERAGING A VARIETY OF TOOLS TO LOWER EMISSIONS A range of options that include improving feed efficiency, use of methane-reducing feed additives, optimizing animal genetics and improving manure management can help reduce overall methane emissions coming from the dairy industry and help it meet climate-focused goals. Use of feed additives, like IntelliBond trace minerals, can help achieve emission reduction goals per unit of energy corrected milk. “If we implement all of this, then we’ll be well on our way to have a substantial reduction,” said presenter Dr. Kebreab. References 1. Naranjo et al., 2020, 2. EDF, 2022, 3 - D Kinley et at. 2016, 4. E Roque et al. 2019, 5. F Roque et al. 2021, 6. G Roque et al. 2019, 7. Jayanegara et al. 2018, 8. Lactanet 0% 0.25% 0.50% 300 200 100 0 Methane Production (g/day) 3 6 9 12 15 18 21 Figure 3. Use of seaweed in diets cut emissions, especially in energy-dense diets.
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