Influence of Feed Upon the Composition of Milk. I. High versus Low Fiber Ration

Based on an 8-wk. hot-weather, single-reversal feeding trial involving two lots of ten cows each--five Holstein and five Jersey--the following information was obtained: Ration B containing 63% more crude fiber and 14% more dry matter than Ration C resulted in highly significant mean differences in favor of Ration B with respect to per cent T.S. and per cent fat, when comparing weekly averages of all 20 cows. Mean differences based on individual cow 4-wk. averages were highly significant with respect to conductivity at 37 C. and per cent fat, and significant with respect to per cent T.S., all in favor of Ration B.