Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 12, 2006
Publication Date: June 14, 2006
Citation: Hall, M. 2006. Dietary carbohydrate impact on milk components. In: Proceedings of the Four-State Dairy Nutrition and Management Conference, June 15, 2006, Dubuque, Iowa. p.79-83. Technical Abstract: Carbohydrates have long been recognized as the primary source of energy in dairy cattle diets, however, their effects on milk production beyond their energy values have not been well explored. There is basic recognition that fiber with its important role in maintaining rumen function can influence milk fat production: too little fiber vs. too much nonfiber carbohydrate (NFC) can lead to milk fat depression. Typically, this effect has been related to reduction in ruminal pH, however, the non-pH effects of the NFC on milk components, and effects associated with their interactions with other dietary components have been reported, but have not been well explored. Research data support the potential for changing milk composition by altering the proportions of sugars, starch and soluble fiber in the diet. The results have varied, but sugars show some potential for increasing butterfat, but show a neutral or negative effect on milk protein. Starch has potential to increase component yield, but excessive feeding has potential to lead to health disorders. Feeds containing soluble fiber and sugars do not appear to enhance yield of milk components of themselves, but may help as an amendment to high starch diets to maintain animal health and productivity. The impact of any dietary carbohydrate will likely be a function of what it is replacing in the diet, the basal amounts of that carbohydrate in the diet before supplementation, and interactions with other dietary components and management. However, based on our current research information, it is unclear what specific dietary changes must be made to get the desired response in milk composition.