Critique of the Cornell Net Carbohydrate and Protein System with emphasis on dairy cattle. 3. The requirements model
2001
Alderman, G. | France, J. | Kebreab, E. (Reading University (UK). Dept. of Agriculture)
The Cornell Net Carbohydrate and Protein System (CNCPS) adopts energy requirements as meals of metabolizable energy (ME) largely as NRC, which are to be used with feed ME values as measured at the maintenance level of feeding. However, the model inserts calculated production level ME values into these NRC standards, equivalent to an upwards correction of about 5 percent to the estimates of ME requirement adopted. The energy accounting of the model is therefore flawed. The maintenance requirement of all breeds of dairy cattle, other than Holstein, are increased by factor of 1.2, based on work with beef suckler cows. The efficiency of ME use for milk synthesis is also raised to a constant 0.65 from the normal range of 0.62 to 0.64 specified in NRC
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