Relation of Ration Sucrose Level and Grain Content to Lactation Performance and Rumen Fermentation

Sixteen cows were used in a 4 X 2 factorial experiment in which sucrose replaced corn at O, 3, 6, and 9% (dry basis) of total dry matter in rations of 30 and 70% grain. Solids-corrected milk yield increased linearly (P<5%) with increments of sucrose. Solids-corrected nfilk (SCM) yield and yield per megacalorie of estimated net energy were significantly lower for the 70%grain than for the 30%-grain rations. Solids-corrected milk/estimated net energy (ENE) increased with increments of sucrose in the 30%-grain ration, but decreased with added sucrose in the 70% grain. Milk fat and solids-not-fat were not significantly altered by sucrose or grain levels.