title: Short communication: Added value of rumination time for the prediction of dry matter intake in lactating dairy cows.
abstract: The objective of the current study was to quantify the change in the prediction of dry matter intake (DMI) resulting from the inclusion of rumination time (RT) in the 2001 National Research Council (NRC) DMI prediction model. Forty-one Holstein cows fed the same total mixed ration were involved in a 10-wk study. Individual DMI were measured daily. The accuracy and precision of the original NRC prediction model, based on body weight, fat-corrected milk, and week of lactation as independent variables, was compared with the accuracy and precision of the same model with RT as an additional independent variable. The RT estimate was significant in the model developed but had a low value (0.031 kg/h). Root mean square prediction errors were very similar in the 2 models (1.70 and 1.68 kg/d) as were the other indicators (R(2), linear bias, random error, and concordance correlation coefficient) selected to compare the models in this study. These results indicate no gain in DMI prediction precision or accuracy when RT is included in the NRC model.
authors.affiliation: LUNAM Université, Oniris, UMR BioEpAR, CS 40706, 44307 Nantes, France; INRA, UMR1300 BioEpAR, CS 40706, 44307 Nantes, France. Electronic address: pierre.clement@oniris-nantes.fr.
authors.forename: P
authors.initials: P
authors.lastname: Clément
authors.affiliation: LUNAM Université, Oniris, UMR BioEpAR, CS 40706, 44307 Nantes, France; INRA, UMR1300 BioEpAR, CS 40706, 44307 Nantes, France.
authors.forename: R
authors.initials: R
authors.lastname: Guatteo
authors.affiliation: INRA, AgroCampus Ouest, UMR1348 Pegase, F-35590 Saint-Gilles, France.
authors.forename: L
authors.initials: L
authors.lastname: Delaby
authors.affiliation: Institut de l'Elevage, 149 rue de Bercy, 75595 Paris, France.
authors.forename: B
authors.initials: B
authors.lastname: Rouillé
authors.affiliation: Institut de l'Elevage, 149 rue de Bercy, 75595 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Chanvallon
authors.affiliation: Evolution, 69 rue de la Motte Brûlon, 35700 Rennes, France.
authors.forename: J M
authors.initials: JM
authors.lastname: Philipot
authors.affiliation: LUNAM Université, Oniris, UMR BioEpAR, CS 40706, 44307 Nantes, France; INRA, UMR1300 BioEpAR, CS 40706, 44307 Nantes, France.
authors.forename: N
authors.initials: N
authors.lastname: Bareille
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D001835:Body Weight; D002417:Cattle; D004032:Diet / Q000662:veterinary*; D005260:Female; D007774:Lactation; D012417:Rumen / Q000378:metabolism*; D013997:Time Factors
keywords: dairy cow; dry matter intake; intake prediction; rumination