Submitted to: Progressive Forage Grower
Publication Type: Popular Publication
Publication Acceptance Date: 10/21/2020
Publication Date: 12/4/2020
Citation: Billman, E.D., Andreen, D.M., Brito, A.F., Soder, K.J. 2020. Red seaweed for reduced methane in grazing systems: does it work. Progressive Forage Grower. 11:22-23.
Interpretive Summary: No Interpretive Summary is required for this Popular Publication. JLB.
Technical Abstract: Dairy and beef production contribute substantial quantities of methane (CH4) to the atmosphere every day due to rumen fermentation processes. One potential solution to reducing these greenhouse gas emissions is by supplementing ruminant feed with red seaweed [Asparagopsis taxiformis (Delile) Trevor; AT], which is antagonistic to CH4-producing microbes in the rumen. An in vitro ruminal fermentation study was conducted at the USDA-ARS Pasture Systems and Watershed Management Research Unit (University Park, PA) to determine the efficacy of adding AT to a forage-based diet. During four 10-d periods (7-d acclimation, 3-d sampling), treatment rates of 0%, 0.5%, 1.0%, and 1.5% AT (dry matter) were added to orchardgrass (Dactylis glomerata L.) basal diets. Treatments were redistributed between four fermentors each period in a Latin square design. During each period CH4 production was monitored at 15-min intervals on each fermentor using a Fourier transform infrared spectrometry (FTIR) gas analyzer, along with pH and temperature. Fermentors were also subsampled for feed digestibility and ammonia levels to calculate nitrogen metabolism. Data were analyzed using the MIXED procedure of SAS with orthogonal polynomial contrasts. Methane production of fermentors with AT treatments was reduced to near-zero within the first 24 hrs and remained so for the duration of each period. Cubic decreases in CH4 were observed with increasing levels of AT inclusion, with the greatest decrease occurring with the initial addition of 0.5% AT. Ammonia N and total volatile fatty acids also decreased cubically with increasing levels of AT inclusion. These findings indicated that AT material is highly effective at reducing CH4 production in vitro, but further research is required to determine other risks to products of fermentation.