COMPARISON OF SORGHUM AND CORN GRAINS IN EARLY AND MIDLACTATION DIETSFOR DAIRY-COWS

Two trials were conducted to compare the effects of corn and sorghum g rains on performance of early and midlactation Holstein dairy cows. In trial 1, 36 multiparous midlactation cows were assigned to one of fou r diets in a 2 x 2 factorial arrangement for 10 wk: 1) grain mixture c ontaining 77% rolled com fed in a TMR, 2) same grain fed separately fr om forage, 3) grain mixture containing 77% finely ground sorghum fed i n a TMR, and 4) same grain fed separately from forage. Grain source an d feeding methods had similar effects on milk yield, milk fat percenta ge, SNF, SCM, and BW. Cows fed sorghum had higher DMI; cows fed com ha d greater efficiency of milk yield. In trial 2, 36 multiparous early l actation cows were assigned to one of four TMR in a 2 x 2 factorial ar rangement for 9 wk: 1) TMR containing 35.5% rolled com, 2) TMR contain ing 35.5% finely ground com, 3) TMR containing 35.5% rolled sorghum, a nd 4) TMR containing 35.5% finely ground sorghum. Grain source produce d no differences in DMI, milk yield, milk fat percentage, SCM, and BW. Cows fed finely ground grain yielded more milk than those fed rolled grain. Finely ground sorghum promoted higher milk protein and SNF perc entages than did finely ground com. Total tract starch digestibility w as greater for corn than for sorghum. These two trials indicate that s orghum grain, when finely ground, supports milk yield and composition similar to that of corn.