Hello To Trans-Fatty Acids and Good-bye To Fatty Liver in Dairy Cows

In dairy cattle, the period of transition from late pregnancy to early lactation is characterized by dramatic changes in nutrient demand that necessitate coordinated changes in body tissue metabolism to meet requirements of energy, glucose and amino acids by the mammary gland (Bauman and Curie, 1980; Bell, 1995; Overton et al., 2001). Failure of the transition cow to appropriately adjust her metabolism to support increased nutrient requirements of early lactation may lead to metabolic disorders, suboptimal milk production and compromised postpartum reproductive efficiency. One of the key metabolic adaptations that occur in support of lactation involves extensive mobilization of body fat to meet the increased demand for energy. However, if the rate of non-esterified fatty acid (NEFA) mobilization from adipose tissue exceeds that of their metabolization in the liver, the syndrome of hepatic lipidosis or fatty liver may result, which can ultimately lead to prolonged recovery from other disorders, increased incidence of health problems, and compromised liver function (Drackley, 1999; Grummer, 1993; Veenhuizen et al., 1991). Therefore, the research missions of our laboratory are 1) to identify dietary components that can reduce periparturient metabolic upsets due to decreased feed intake, 2) improve milk production without negatively affecting its composition, and 3) stimulate ovarian activity to improve postpartum reproductive efficiency in dairy cattle.