Cornell Net Carbohydrate and Protein System

For the Cornell net carbohydrate and protein system for predicting the requirements of cattle, the intake of lactating cows is predicted from the net energy content of the food and the milk yield and milk fat content of the animal. Predicted values are then adjusted for six other factors age, breed and body fat content of the cattle, the inclusion in the diet of any additives, the environmental temperature, and another component of the environment called mud . 

The fractionation of the carbohydrates by analysis is currently most fully developed in the Cornell net carbohydrate and protein system for ruminant diets. This is based on the Van Soest analytical system, with the addition of other standard techniques, to derive the following fractions in foods ... 

Caimas, A., L.O. Tedeschi, A.S. Atzoriand D.G. Fox. 2006. Prediction of energy requirements for growing sheep with the Cornell Net Carbohydrate and Protein System. In J. Dijkstra (ed.), Nutrient Digestion and Utilization in Farm Animals. CABI Publishing, Cambridge, MA 99-113. 

Fox, D.G., L.O. Tedeschi, T.P. Tylutki, J.B. Russell, M.E. Van Amburgh, L.E. Chase, A.N. Pell and T.R. Overton, 2004. The Cornell Net Carbohydrate and Protein System model for evaluating herd nutrition and nutrient excietioiL... 

Cannas, A., 2000. Sheep and cattle nutrient requirement systems, ruminal turnover, and adaptation of the Cornell Net Carbohydrate and Protein System to sheep. Ph.D. dissertation, Cornell University, Ithaca, NY, USA, 337 pp. 

Protein degradation in the rumen is important for the protein value of feeds and thereby the utilization of feed nitrogen by ruminants, and can be estimated using different methods. The in situ method estimates the protein degradation profile in the rumen environment. The method used in the Cornell Net Carbohydrate Protein System (CNCPS) estimate soluble and insoluble nitrogen (N) fractions in feeds with different degradation characteristics. In CNCPS, crude protein (N><6.25) is partitioned into 5 fractions. A, Bj, B2, B3 and C with different degradation characteristics. 

In the Cornell net protein and carbohydrate system, food protein is separated into fractions based on a combination of borate-phosphate extractions and the detergent system of carbohydrate analysis of Goering and Van Soest (Fig. 13.4). 

PDI = the French protein digested in the intestine system CPFD = the German crude protein flow at duodenum system DVE = the Dutch digestible protein in the intestine system AAT-PBV = the Nordic system AP = the American absorbed true protein system ADPLS = the Australian apparently digested protein leaving the stomach system CNCPS = the Cornell net protein and carbohydrate system. 

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