Michael E. Van Amburgh - Associate Professor
PhD from Cornell University
Graduate fields: Animal Science
Area(s) of interest: dairy cattle nutrition.
Teaching:
Email: mev1@cornell.edu
Current Research
Previous work has focused on the effects of accelerated pre-pubertal body growth on first lactation milk yield of Holstein heifers and how to better meet the nutrient requirements of this class of growing animal. We demonstrated that body weight gains of up to 1 kg per day did not significantly affect first lactation milk yield. The aim of current and future work is to develop more accurate descriptions of nutrient supply and requirements in order to optimize growth and profitability.
The focus of work in my lab is the development of new feeding and management strategies for growing ruminants, particularly dairy heifers. Studies currently being conducted and those planned by current graduate students are: the development of nutrient requirements for milk fed, transitional and pre-pubertal Holstein heifers; investigation of the age, weight and growth rate effects of somatotropin response in milk fed calves; the development of a mechanistic model of ionophore action in the rumen including the protein sparing effect and a pH effect on ionophore activity and/or microbial activity; and the evaluation of protein and somatotropin interactions on heifer growth, carcass composition and mammary development.
Current methods for describing non-structural carbohydrates rely on by difference calculations. Prediction of end-products of fermentation and rumen escape are dependent on accurate descriptions of substrates available. Other work in the lab currently being conducted includes evaluation of ruminant feedstuffs to more accurately describe carbohydrate and protein fractions. We are employing total dietary fiber methods to determine the content of soluble fiber in ruminant feedstuffs in order to determine the extent to which this fraction may require more routine analysis.
Data generated will be used to enhance the predictive capacity of the Cornell Net Carbohydrate and Protein System. I use the model as a tool in Animal Science 312 to teach basic principles of ruminant nutrition in an integrated form. Heifer growth data has been integrated into Cornell Cattle Systems 5 nutrition/profitability software in an effort to more accurately predict the production economics of varying replacement growth strategies.
Another area of interest is nutritional management of lactating cattle. A full lactation field study evaluating the effects of bST response within herds is underway. Cows are stratified by parity and further stratified into thirds based on milk yield and lactation projections up to 60 days in milk. Somatotropin is administered to cows in the top third and bottom third of the herd by parity. The hypotheses are that high producing cows will respond to bST without complication and that the response will be greater than lower producing cows. In addition, higher producing cows will replenish energy reserves at a slower rate but will compensate by increasing feed intake to meet nutrient needs.