Session: Ruminant Nutrition V: Forages, Methane, and Digestibility

328 - The Potential Role of Two Red Seaweeds That Promote Anti-methanogenic Activity and Rumen Fermentation Profiles Under Laboratory Conditions

Saturday, July 17, 2021

9:15 AM – 9:30 AM EST

Location: Kentucky International Convention Center (KICC), L005/009

Presenting Author(s)

byeng ryel min

Research Animal Scientist
PH.D.
Bushland, Texas

PDF Slides

Author(s)

GG

Giusi Genovese

dr.
Messina, Sardegna
LC

Lana Castleberry

Ms
Bushalnd, Texas
CL

Cathy Lockard

dr
Bushland, Texas
HW

Heidi Waldrip

Dr.
Bushland, Texas
dM

daniel Miller

Dr.
Lincoln, Nebraska
AA

Alexia Akbay

MS.
Kailua-Kona, Hawaii
MM

Marina Morabito

Dr.
Messina, Sardegna
AM

Antonio Manghisi

Dr.
Messina, Sardegna
DS

Damiano Spagnuolo

MS
Messina, Sardegna
DB

David Brauer

PhD
Bushland, Texas

Ruminal methane (CH₄) production results from carbohydrate fermentation by ruminal microbiota (methanogens) to produce CH₄, volatile fatty acids (VFA), carbon dioxide (CO₂), nitrous oxide (N₂O), and hydrogen (H₂) in a reduction pathway. The aims of this study were to assess the effects of two red seaweed (RSW) species (Asparagopsis taxiformis and A. armata; collected from Messina, Italy). The two RSW were identified by DNA barcoding and genetic data were deposited in BOLD Systems (REAPP006-21, REAPP004-21, respectively). The two RSW were used at dietary inclusion levels (0, 2, and 4% as-fed basis) in an anaerobic in vitro study (39°C for 48-h) to examine greenhouse gas (GHG) production and VFA profiles. Gases were collected using an ANKOM Gas Production system and analyzed for CH₄ and N₂O by gas chromatography. Asparagopsis taxiformis contained higher levels of bromoform (201 vs. 7.0 mg/kg DM), iodine (4820 vs. 3260 ppm), and crude protein (16 vs. 15.6% DM), than A. armata, which contained higher levels of acid detergent fiber (ADF; 7.7 vs. 19.0%) and neutral detergent fiber (NDF; 13.2 vs. 19.2%), respectively. RSW supplementation increased total gas, butyrate and valerate production (P < 0.01), while production of CH₄ (mg/g DM), acetate (A), propionate (P), A/P ratios and in vitro dry matter digestibility (IVDMD; % DM) were reduced (P < 0.01) as RSW supplementation increased. In the presence of A. taxiformis, production of N₂O (µg/g DM), tended to be less (P = 0.1) at 2% DM, but increased (P < 0.01) N₂O production with A. armata at the 2 and 4% DM. Therefore, it may be possible to suppress methanogenesis both directly and indirectly by addition of RSW. To efficiently use seaweeds as feed ingredients with nutritional and environmental benefits, more research is required to determine the mechanisms underlying seaweed and dietary substrate interactions.