Uncertainty in Nutritive Measures of Mixed Livestock Rations

¹ Department of Agricultural and Biological Engineering, The Pennsylvania State University, University Park 16802
² Department of Dairy and Animal Science, The Pennsylvania State University, University Park 16802

Totally mixed rations are an increasingly popular feeding method for high producing dairy cows. Although a TMR formulation may be technically correct, many sources of variation influence the ration actually consumed by cows. To understand and to control variation among batches, uncertainty analysis was applied to TMR feeding to identify sources of error or uncertainty that contribute most to overall uncertainty in diet characteristics. A spreadsheet implementation of the uncertainty analysis allowed for rapid assessment of error sources that may reduce productivity. For a sample TMR, uncertainty in ingredient nutrient concentrations contributed most to overall uncertainty. Uncertainty in forage DM content and amounts of ingredients with high nutrient concentrations also contributed substantially to overall uncertainty.

Key Words: dairy feeding • formulation • total mixed rations • uncertainty

Submitted on January 31, 1994
Accepted on July 26, 1994