Evaluation of the feed intake models in the Nordic feed evaluation system NorFor

Abstract

The objective of this study was to evaluate the feed intake models in the Nordic feed evaluation system NorFor. Data from 196 feeding experiments with dairy cows, and 17 experiments of periodical data, and 135 experiments of complete data with growing cattle were used in the evaluation by mixed model regression. The feed intake by both dairy cows and growing cattle were overestimated by the models. A linear bias indicated that over prediction increased with level of intake both by dairy cows and growing cattle. Most animal and diet factors were significantly related to the residuals, which indicated that those factors did not act independently in the predictions of feed intake. This kind of errors can restrict future ration formulation and animal performance, since animal production parameters included in the prediction models will be a consequence of the diet fed at the time they were measured.

Keywords:

• Cattle
• dairy cow
• meta-analysis
• metabolic
• physical
• prediction models
• voluntary intake

Acknowledgment

The authors acknowledge the Regional Farmers' Foundation for Agricultural Research in Northern Sweden (RJN) for financial support of the project.