Prediction of food intake

An example of prediction equations for intake that may be used in conjunction with feeding standards is provided by the UK Agricultural Research Council s Technical Committee on Responses to Nutrients, which constructed a series of equations for predicting the intake of grass silage by cattle (both dairy and beef) fed on silage and concentrates. The following is an example of the equations derived for beef cattle  

TheAustrahan Standing Committee on Agricultme has adopted a computer-based model called GRAZFEED to predict the intake of grazing ruminants. The animal factors in this model include the animal s current weight in proportion to its so-called 

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 . 

Control mechanisms for food Intake operate at the metabolic level (e.g. metabolite concentrations signalling the need to start or stop feeding) and at the level of the digestive system (e.g. signais from the degree of fill of the rumen). In addition, intake is influenced by features of the environment such as temperature. 

In monogastric animals, control is mainly metabolic. In the short term, blood concentrations of glucose and other nutrients may control intake via the hypothalamus. In the longer term, fat depots send signals to the brain by the hormone messenger leptin. 

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Blummel, M. and E.R. 0rskov, 1993. Comparison of in vitro gas production and nylon bag degradability of roughages in predicting of food intake in cattle. Anim. Feed. Sci. Technol. 40, 109-119. 

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