Study in Progress

Statement of Task

A committee will prepare a report that reviews the scientific literature on the nutrition of dairy cattle and updates the nutrient requirements contained in the 2001 NRC publication Nutrient Requirements of Dairy Cattle. The report will contain a comprehensive analysis of recent research on the feeding and nutrition of dairy cattle, including research on the amounts of amino acids, lipids, fiber, carbohydrates, minerals, vitamins, and water needed by preweanling, growing, reproducing, and lactating dairy cattle.

The committee will evaluate new information to improve the accuracy of predicting animal performance from nutrient input and of predicting nutrient input when animal performance is known. Consideration will be given to variables that may affect nutrient requirements, such as environmental conditions and type of production system. The report will also address the effects of mycotoxins and other toxins; recent research on energy utilization by dairy cattle; the composition of feed ingredients, mineral supplements, and feed additives routinely fed to dairy cattle; coproducts from the biofuels industry; and the accuracy of estimating energy in forages using the NRC prediction equation.

New information about nutrient metabolism and utilization; antioxidants; effects of feed grain processing on starch rate and site of digestion; feed additives that alter rumen metabolism and postabsorptive metabolism; and rumen and metabolic modifiers will be included. The committee will also review nutritional and feeding strategies that minimize nutrient losses in manure and reduce greenhouse gas production and include a discussion of the effect of feeding on the nutritional quality and safety of dairy products. Future areas of needed research will be identified. Depending on the extent of new information available, an update of the current computer model to calculate nutrient requirements may be developed. Appropriate testing and analysis of any new model will be conducted.