Variation of Fatty Acids in Cool-Season Grasses

Cool-season grass samples were collected and analyzed for omega-6 and omega-3 fatty acid (FA) content. Perennial ryegrass, tall fescue, orchardgrass, and Kentucky bluegrass samples were collected on four harvest dates from various trials conducted in the eastern portion of the Appalachian Mountains. There was a greater change in linolenic acid (C18:3) than linoleic acid (C18:2) concentrations in all forage species and across seasons. Perennial ryegrass had higher levels of linolenic acid compared to the other grasses on most dates other than in August, when it did not provide forage. Linoleic acid concentrations changed less across seasons and were generally lower in tall fescue compared to the other grass species, which tended to contain similar levels. There was a species x date interaction on FA concentrations. Kentucky bluegrass had a peak concentration of linoleic acid in August. Concentration in orchardgrass fluctuated slightly across seasons, while concentrations in tall fescue and perennial ryegrass decreased as the season advanced. Identification of FA concentrations in plant species and managing species diversity in pastures to increase and stabilize the content of omega-3 FA in meat and milk products appears to be a valuable tool for managers to manipulate FA characteristics of products from pasture-based systems.