76 Amino acid and fatty acid profiles of rapidly growing pasture from six states in the USA

Pasture is a natural forage source for horses, but nutritional data is limited in terms of the fatty acid and amino acid profiles of fresh grasses. More information about the nutrient content of pasture can help to inform the formulation of supplemental feedstuffs for horses; especially for those without access to pasture. The objective of this study was to determine the nutrient profile, including fatty acid and amino acid content, of a variety of both cool season and warm season grasses, in their rapid phase of growth in the United States. Grass samples (n = 6) were collected from New York (NY), Colorado (CO), Tennessee (TN), Texas (TX), South Carolina (SC) and Missouri (MO) from May 10th – 25th 2018 from horse pastures following the directives of Dairy One Forage Laboratory for identifying, collecting (12–20 samples from each pasture), freezing and shipping fresh pasture. All pastures had vegetation >10 cm and were actively grazed by horses. Samples were analyzed for nutrient content, amino acid profile, and fatty acid profile by Cumberland Valley Analytical Services (Waynesboro, PA). The basic nutrient content of the pasture grasses was as expected for rapidly growing pasture, and the amino acid and fatty acid profiles were enlightening given the lack of published data in this area (Table 1, limited data shown). The top 3 amino acids found across all the pasture samples were glutamic acid, aspartic acid and leucine. The top 3 fatty acids found across all pasture samples were linolenic acid, palmitic acid and linoleic acid. Given that pasture is a major source of calories and nutrients for many horses, it is valuable to understand its nutrient content and how it is contributing to the health of horses. In addition, once these nutrient values are known, they can inform the creation of supplemental feedstuffs for horses, to mimic the nutritional content of fresh pasture.