Wet tomato pomace ensiled with corn plants for dairy cows

The fermentation characteristics and nutritive value of a mixture of whole corn plants and wet tomato pomace were studied. Laboratory silos were filled with mixtures of corn plant dry matter (DM) and tomato pomace DM in the following ratios: 100:0, 94:6, and 88:12. The initial pH of the mixtures decreased linearly as the amount of tomato pomace increased, but no treatment effects were found after 3 d of ensiling. At d 56, concentrations of lactic acid and nonprotein N (as a percentage of total N) decreased linearly as tomato pomace increased. Whole corn plants were chopped from a single field, mixed with 0 or 12% tomato pomace (percentage of DM), and ensiled in two concrete stave silos. The addition of tomato pomace increased concentrations of crude protein (7.6 to 9.8%), lignin (2.4 to 6.1%), and fatty acids (2.5 to 3.8%). Both silages were mixed into an isonitrogenous total mixed ration that contained 40% concentrate. The total mixed rations were fed to lactating dairy cows for 60 d. Milk production (35.5 kg/d), milk composition, DMI (22.7 kg/d), nutrient digestibility, and N balance were not affected by the addition of tomato pomace. Wet tomato pomace can be blended with corn plants before ensiling without greatly altering fermentation. The nutritional value of the mixture was equivalent to that of untreated corn silage.