Evaluation of a Mechanistic Model of Glucose and Lipid Metabolism in Periparturient Cows

• Published in: Journal of dairy science 2008-11, Vol.91 (11), p.4293-4300
• Main Authors: Guo, J., Peters, R.R., Kohn, R.A.
• Format: Article
• Language: English
• Subjects: accuracy; Animal productions; Animals; Biological and medical sciences; birth weight; blood glucose; body condition; Body Constitution; body fat; Body Weight; calves; carbohydrate metabolism; Cattle - physiology; Cattle Diseases - metabolism; cow feeding; dairy cows; dry matter intake; Eating; Female; Food industries; Fundamental and applied biological sciences. Psychology; glucose; Glucose - metabolism; ketosis; Ketosis - metabolism; Ketosis - veterinary; Lactation; lipid metabolism; Lipid Metabolism - physiology; mechanistic models; metabolism; Milk - metabolism; Milk and cheese industries. Ice creams; milk yield; model evaluation; Models, Biological; nutritional status; periparturient cow; Postpartum Period; precision; Pregnancy; prepartum period; regression analysis; Reproducibility of Results; Sensitivity and Specificity; simulation models; Terrestrial animal productions; Vertebrates
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2007-0962

A mechanistic model was previously developed to quantitatively describe glucose and lipid metabolism in periparturient cows. The objectives of the current study were to evaluate the accuracy and precision of the model by comparing predictions to data collected in an independent experiment; to identify the critical metabolic processes for ketosis development; and to use the model to evaluate the relative importance of dry matter intake, calf birth weight, milk yield, and body condition score on nutrition management. Residuals (observed – predicted) were regressed on model predictions using the independent data for the model inputs, and prediction error was calculated. Each model parameter (e.g., the rate of glucose consumption by peripheral tissues) was increased independently by 1 standard deviation to identify the critical metabolic processes for ketosis development. Critical control points to prevent ketosis were identified by increasing the driving variables of the model by 1 standard deviation to estimate the response in ketone body formation. The root mean square prediction error was 0.527mM for ketone body predictions. The sensitivity analysis indicated that in the first few days of lactation, the rate of nonesterified fatty acid utilization had a greater effect on ketone body concentrations in periparturient cows than the other parameters tested in the model. The model was consistent with the knowledge that over-fattening during the prepartum period should be avoided to help prevent ketosis.