A COMPARISON OF TWO METHODS OF COMBINING ALFALFA CUBES WITH CORN SILAGE FED TO LACTATING COWS

Abstract

Sixteen Holstein cows in early lactation were assigned to a switch-back experiment consisting of two experimental periods 35 days in length separated by a 7-day changeover period. Treatments consisted of two feeding systems, alfalfa cubes ensiled with corn silage or alfalfa cubes fed with the corn silage. When cows were fed corn–alfalfa cube silage they consumed more forage, 2.26 vs. 2.16% of body weight per cow per day than when they were fed the alfalfa cubes with the silage. Fat-corrected milk yield was somewhat higher, 25.4 vs. 24.0 kg/day; fat percent and fat yield were greater, 3.13 vs. 2.70% and 918 vs. 814 g/day for corn–alfalfa cube silage as compared to cubes added at feeding time. However, milk yield was greater, 29.9 vs. 29.1 kg/day, and milk lactose percent was greater, 5.26 vs. 5.18% for cows fed cubes at feeding time compared to cows fed corn–alfalfa cube silage. There was no difference between feeding systems in blood minerals or metabolites with the exception of plasma urea nitrogen which was higher, 20.2 vs. 17.2 mg %, for the alfalfa cubes fed with the corn silage. Apparent dry matter and protein digestibility for the total ration were 68.1 and 71.6% when corn alfalfa cube silage was fed compared to 65.4 and 68.5% when the cubes were fed with the corn silage (P < 0.05). It was concluded from this study that alfalfa cubes ensiled with corn silage was an effective method of increasing the dry matter and protein content of corn silage and in improving the digestibility of the total ration.