High-Moisture Corn Preserved by Different Methods for Lactating Cows

Three trials with 20 lactating Holstein cows per trial were to compare rolled dry shelled corn with high-moisture (74.8% dry matter) rolled shelled corn preserved in oxygen-limiting storage (trial 1) with rolled shelled corn (71.6% dry matter) preserved with 1% propionic acid in a concrete bunker silo (trial 2) and with ground ear corn (72.5% dry matter) preserved with .5% propionic acid in a concrete bunker silo (trial 3). Cows were fed complete mixed rations containing (dry basis) 41.4% corn silage; 16.2% alfalfa haylage; 33.8% corn; and 8.6% soybean meal, vitamins, and mineral mix. Milk yield, its composition, feed intakes, and body weight changes were similar for cows fed dry corn and high-moisture corn in each of the three trials. Ruminal concentrations of total volatile fatty acids and propionate concentrations were higher and molar proportions of acetate and ruminal pH were lower in cows fed high-moisture corn diets.