Juan Rivera's MSc Defence

Cup plant (Silphium perfoliatum Sp.) is characterized by high biomass yields and the ability to grow on mar-ginal lands where common dairy forage sources are unable to thrive. The objective of this research was to as-sess its feeding value for dairy cows by comparative evaluations of DM degradability in vitro and in situ, and lactational performance in vivo when fed in partial replacement (13% of ration DM) of corn and alfalfa silag-es. In vitro results showed that cup plant silage only had lower DMD than the alfalfa silages, and lower pH than corn silage. In situ results showed a smaller DMD than corn and alfalfa silages, also smaller soluble and potentially degradable fractions . Lactational results showed decreased DMI and milk protein percentage, also cows sorted more against long particles. Altogether, cup plant inclusion showed no adverse health ef-fects, sustained high milk yields, and warrants further research of its inclusion in dairy rations.