Sugar Levels in Dairy Cattle Rations: When is the addition of sugar to dairy cattle diets justified

摘要

The addition of sugars to dairy cattle diets has not always unproved milk yield, ruminal microbial protein yields or milk components (Hristov and Ropp 2003; McCormick etal. 2001, Morales etal. 1989). In contrast, other trials have reported increases in milk yield and milk fat percent or increases in NDF digestibility (Broderick and Radloff, 2003, Broderick and Smith 2001, Varga etal. 2001, Oldick etal. 1997). It would be great if the addition of sugar to dairy cattle diets was a black and white or crystal clear issue. Unfortunately it is not crystal clear because the rumen is a complex ecosystem and this complex ecosystem does not always respond positively to sugar additions to the dairy diet. This rumen ecosystem will respond positively to the addition