Cool-Season Forage Grass Palatability and Preference in Dairy Cattle.

Cool-season forage grasses have been shown to have varying ranges of palatability to the animals that consume them. Palatability is often associated with forage quality factors, such as low fiber content, high non-structural carbohydrate levels, high crude protein, and lack of anti-quality factors such as tannins. Other factors such as total available forage, water content, texture, color, smell, and tensile strength can also play a factor in animals preferring one species or variety over another. Due to the high correlation of forage intake and quality to dairy cattle milk production, it is a prime area to examine animal preference in order to determine the optimal cool season grass for grazing. The objective of this study was to determine dairy cattle preference amongst four species of cool-season forage grasses: orchardgrass (Dactylis glomerata L.) (8 varieties), tall fescue [Lolium arundinaceum (Schreb.) Dumort.] (5 varieties), perennial ryegrass (Lolium perenne L.) (5 varieties), and festulolium [x Festulolium braunii (K. Richt.) A. Camus.] (6 varieties); to determine the most palatable variety and species to dairy cattle. Over the 2014 growing season three grazing sessions were conducted (June, July, and September). These have shown that individual varieties do not have significant effect on percent of forage consumed (P > 0.10). However, the interaction between each species and grazing session was significant (P< 0.01) with orchardgrass having the greatest mean consumption in June. Tall fescue had the greatest mean consumption in July. There were no statistical differences among species in the September grazing. This indicates that physiological and morphological differences in each species of cool-season grass throughout the growing season play a larger role in animal preference than variety or species alone. Possible factors involved in this could include available forage and forage quality which were measured as well and will be correlated to percentage consumed. Analysis of forage quality from these samples is ongoing and will be reported and correlated to preference upon completion.