Researcher(s)
- Madison Tobat, Pre-Veterinary Medicine and Animal Biosciences, University of Delaware
Faculty Mentor(s)
- Tanya Gressley, Animal and Food Sciences, University of Delaware
Abstract
Methionine (Met) is an amino acid that dairy cows need for milk protein production. However, when methionine is fed directly, most of it is broken down by microbes in the rumen before it can be absorbed in the small intestine and used by the cow. Methionine hydroxy analog (HMB) and the isopropyl ester form of the hydroxy analog (HMBi; 2-hydroxy-4-(methylthio)butanoic acid isopropyl ester) were made to increase the amount of methionine available to the cow after passing through the rumen. The objective of this study is to compare the bioavailability of methionine among these treatments. Four ruminally cannulated lactating Holstein cows were used in a 4 × 4 Latin square design with four treatment periods. Treatments included a DL-methionine control infused into the abomasum, HMB infused into the rumen, and two HMBi products infused into the rumen. Blood samples were collected at 0, 1, 2, 3, 4, 6, 9, 12, 24, and 48 hours after treatment. Plasma methionine concentrations will be measured using a standard curve, and the area under the curve (AUC) will be used to compare how much methionine is available from each treatment. It is expected that differences in plasma methionine concentrations will show differences in how effectively each product delivers methionine.