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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Plant, Soil and Nutrition Research » Research » Publications at this Location » Publication #201358
Title: A model for precision feeding of dairy cattle

Author
item TYLUTKI, T. - CORNELL UNIVERSITY
item FOX, D. - CORNELL UNIVERSITY
item DURBAL, V. - CORNELL UNIVERSITY
item TEDESCHI, L. - CORNELL UNIVERSITY
item Russell, James
item VAN AMBURGH, M. - CORNELL UNIVERSITY
item OVERTON, T. - CORNELL UNIVERSITY
item CHASE, L. - CORNELL UNIVERSITY
item PELL, A. - CORNELL UNIVERSITY

Submitted to: Animal Feed Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/2007
Publication Date: 7/25/2008
Citation: Tylutki, T.P., Fox, D.G., Durbal, V.M., Tedeschi, L.O., Russell, J.B., Van Amburgh, M.E., Overton, T.R., Chase, L.E., Pell, A.N. 2008. A decision support system for dairy herd nutrition management. Animal Feed Science And Technology. 143:174-202.

Interpretive Summary: Ration formulation for cattle is confounded by the fact that feedstuffs are fermented in the rumen prior to intestinal digestion and absorption, but previous work indicated that this obstacle by circumvented by a computer model that simulated ruminal fermentation, absorption and metabolism of nutrients. This paper describes the attributes of version 6.0: 1) user interface to improve speed and accuracy, 2) expanded carbohydrate pools to include sugars, soluble fibers, and 3) organic volatile fatty acids. A fat program describes biohydrogenation and fatty acid absorption from the intestine. The model was re-organized by utilizing an object-oriented approach in which physiological functions (e.g. growth, lactation, pregnancy, rumen, and intestines) are programmed as objects. The interface follows a farm, location, and group flow, which decreases the number of inputs required per cattle group and allows for more rapid evaluation of diets, feed requirements and nutrient excretion by location, group, and herd.

Technical Abstract: The Cornell Net Carbohydrate and Protein System (CNCPS) predicts cattle requirements and nutrient supply for site-specific situations. This paper describes the CNCPS version 6 (CNCPSv6), which represents a re-engineering and updating of previous versions with the following objectives: 1) improve the organization of the model and user interface to improve speed and accuracy in formulating diets for a herd of dairy cattle, 2) expand the carbohydrate pools to include sugars, soluble fibers, and organic and volatile fatty acids, 3) integrate the fat model to account for ruminal lypolization and biohydrogenation, and absorption of fatty acids in the small intestine, and 4) review the computational sub-models and correct as needed or update with new information. The CNCPSv6 model was re-organized by utilizing an object-oriented approach in which physiological functions (e.g. growth, lactation, pregnancy, rumen, and intestines) are programmed as objects. The interface follows a farm, location, and group flow, which decreases the number of inputs required per cattle group and allows for more rapid evaluation of diets, feed requirements and nutrient excretion by location, group, and herd. The revised implementation of the body reserves sub-model allows accounting for fluxes in energy reserves when formulating diets. Updated equations and coefficients include the prediction of rumen ammonia balance and feed passage rates, indigestible DM, MP lactation efficiency, and DMI. The CNCPSv6 was evaluated with data from individually-fed lactating dairy cows from three independent studies. As implemented, CNCPSv6 accounted for a similar amount of the variation (86%) in first limiting (ME or MP) milk production as CNCPSv5 but with a lower bias (1% vs. 4%, respectively). We concluded the re-engineering and updating of the CNCPS improved its ability to formulate and evaluate a feeding program for a herd of dairy cattle with greater accuracy and efficiency.