INS and metabolic disease: Intravenous glucose tolerance tests showed IR in Holstein cows due to increased lipid levels. This IR affects cows during the time of giving birth through elevation of NEFA, which causes adipocytes to become more resistant to insulin. This, in turn, increases the concentration of NEFA in the blood, potentially leading to metabolic disorders related to energy imbalance. Tallow was used in emulsion to deliver the NEFA. This study suggests how specific diets can either support or hinder the cows’ ability to complete lactation.