| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Animal Science, Cornell University, Ithaca, NY 14850
Six prediction equations for dry matter intake (DMI) were evaluated for accuracy with independent data. The equations were selected based on ease of parameter measurement and practical on-farm use. The equations were assessed for accuracy of predicting individual weekly DMI for primiparous (n = 105) and multiparous (n = 136) cows; three-fourths of these cows were supplemented with a sustained-release form of bovine somatotropin (bST). Large variations in accuracy were identified across the six prediction equations for effects of parity and bST. Prediction accuracy of all equations for cows in wk 1 to 24 of lactation was better for primiparous cows than for multiparous cows. Precision of prediction equations was poor for cows in wk 8 through 12 of lactation and for cows in >40 wk of lactation. The equation for DMI with the best accuracy measured by a low total lactation mean square prediction error was the modified equation of the National Research Council: DMI (kilograms per day) = –0.293 + 0.372 x fat-corrected milk (kilograms per day) + 0.0968 x body weight0.75 (kilograms). However, the overall mean bias (predicted minus observed) of the prediction of weekly DMI of a single cow was high for all equations, including the modified equation of the National Research Council. For wk 2, 4, 8, 10, and 20 of lactation, the mean bias for the modified equation was +6, +3.4, –1.3, –2.1, and –2.8 kg/d. The accuracy of prediction was lower for cows treated biweekly with bST. High yielding cows and cows treated biweekly with bST had higher milk yields in relation to body weight, and standardized prediction equations for DMI were less accurate.
Key Words: feed intake • intake models • prediction equations
Submitted on November 6, 1995
Accepted on August 9, 1996
This article has been cited by other articles:
|
|
 |
|
  M. D. Hanigan, A. G. Rius, E. S. Kolver, and C. C. Palliser A Redefinition of the Representation of Mammary Cells and Enzyme Activities in a Lactating Dairy Cow Model J Dairy Sci, August 1, 2007; 90(8): 3816 - 3830. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Shah and M. R. Murphy Development and Evaluation of Models to Predict the Feed Intake of Dairy Cows in Early Lactation J Dairy Sci, January 1, 2006; 89(1): 294 - 306. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. N. Hristov, W. J. Price, and B. Shafii A Meta-Analysis on the Relationship Between Intake of Nutrients and Body Weight with Milk Volume and Milk Protein Yield in Dairy Cows J Dairy Sci, August 1, 2005; 88(8): 2860 - 2869. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. N. Hristov, W. J. Price, and B. Shafii A Meta-Analysis Examining the Relationship Among Dietary Factors, Dry Matter Intake, and Milk and Milk Protein Yield in Dairy Cows J Dairy Sci, July 1, 2004; 87(7): 2184 - 2196. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Halachmi, Y. Edan, U. Moallem, and E. Maltz Predicting Feed Intake of the Individual Dairy Cow J Dairy Sci, July 1, 2004; 87(7): 2254 - 2267. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Hayirli, R. R. Grummer, E. V. Nordheim, and P. M. Crump Models for Predicting Dry Matter Intake of Holsteins During the Prefresh Transition Period J Dairy Sci, May 1, 2003; 86(5): 1771 - 1779. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Fuentes-Pila, M. Ibanez, J. M. De Miguel, and D. K. Beede Predicting Average Feed Intake of Lactating Holstein Cows Fed Totally Mixed Rations J Dairy Sci, January 1, 2003; 86(1): 309 - 323. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. P. McNamara and J. E. Pettigrew Protein and fat utilization in lactating sows: II. Challenging behavior of a model of metabolism J Anim Sci, September 1, 2002; 80(9): 2452 - 2460. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
