Reducing methane emissions from livestock is crucial for agricultural sustainability, especially in the dairy sector, which emits high levels of methane. Seaweed-based supplements for livestock, like Asparagopsis taxiformis, offer promise in mitigating emissions from cattle without harming productivity, along with a range of other benefits. Little research to date has been conducted to understand how these supplements are being marketed and sold to dairy farms, and why they are marketed that way: this information can help ensure that these benefits will be realized. This study presents findings from a qualitative analysis of dairy feed suppliers in the Northeast United States, providing insights into their perspectives on seaweed supplements. It explores the differences between organic and conventional feed suppliers, including their perceived benefits and challenges of feeding seaweed. Feed suppliers stated that the benefits of feeding seaweed supplements include micromineral supplementation, reduced somatic cell count, reduced methane emissions, and decreased use of synthetic mineral supplements. Barriers to feeding seaweed include cost, the volume requirements of mills, supply inconsistencies, and a lack of investment from the conventional dairy industry. Feed suppliers also provided insights into what information they need about seaweed supplements to feel comfortable recommending them to their farmer customers, such as more scientific evidence and farmer recommendations. Understanding perceived benefits and barriers lays the foundation for further exploration of supply chain dynamics and stakeholder considerations in promoting sustainable livestock practices.