Seaweed Extracts Show No Anti-Methanogenic Activity in Beef Heifers

Strategic Insights -

Recent research has been published on the effects of seaweed extracts on rumen fermentation, nutrient digestibility, and methane emissions in beef heifers. The study, conducted by the Lethbridge Research and Development Centre, found that whole Ascophyllum nodosum and a seaweed extract generated from Himanthalia elongata did not demonstrate anti-methanogenic activity in a high-forage diet. The research involved a replicated 3 x 3 Latin square design using six ruminally cannulated beef heifers fed a basal diet consisting of 52% barley silage, 44% barley straw, and 4% mineral supplement. The study concluded that neither the whole A. nodosum nor the H. elongata extract had an effect on methane production or yield.

Key Takeaways:

  • The study used a replicated 3 x 3 Latin square design with six ruminally cannulated beef heifers to assess the effects of whole Ascophyllum nodosum and a seaweed extract generated from Himanthalia elongata on rumen fermentation, nutrient digestibility, and methane emissions.
  • The basal diet consisted of 52% barley silage, 44% barley straw, and 4% mineral supplement (dry matter basis).
  • Whole A. nodosum and H. elongata extract were supplemented into the diet at 2% of dietary dry matter, replacing equal proportions of barley silage and barley straw.
  • The study found no effect of treatment on the production of ammonia (NH3), protozoa counts, total volatile fatty acids, or ruminal pH.
  • The apparent total tract digestibility of neutral detergent fibre (NDF) and acid detergent fibre (ADF) was increased (p 0.05) with the addition of A. nodosum or H. elongata extract.
  • Neither the whole A. nodosum nor the H. elongata extract demonstrated anti-methanogenic activity in a high-forage diet.

Statistics:

  • The study used six ruminally cannulated beef heifers.
  • The basal diet consisted of 52% barley silage, 44% barley straw, and 4% mineral supplement (dry matter basis).
  • Whole A. nodosum and H. elongata extract were supplemented into the diet at 2% of dietary dry matter, replacing equal proportions of barley silage and barley straw.
  • The study found a 5% increase in apparent total tract digestibility of NDF and ADF with the addition of A. nodosum or H. elongata extract.
  • The study concluded that neither the whole A. nodosum nor the H. elongata extract had an effect on methane production or yield.

Sources:

  • Effect of Whole Seaweed and Seaweed Extract On Rumen Fermentation, Nutrient Digestibility, and Methane Emissions of Beef Heifers Fed a High-forage Diet. Canadian Journal of Animal Science, 2025;105.
  • Canadian Journal of Animal Science, Canadian Science Publishing, 123 Slater Street, Suite 610, Ottawa, On K1P 5H2, Canada. (NRC Research Press - www.nrcresearchpress.com/; Canadian Journal of Animal Science - pubs.aic.ca/journal/cjas)
  • Stephanie A. Terry, Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, Ab T1J4B1, Canada.
  • Fisayo Oretomiloye, Trevor Coates, Maria Hayes, Additional authors for this research.