It was studied the effects of replacing ground corn with coffee hulls on intake, apparent digestibility, and milk production and composition of lactating dairy cows. Twelve Holstein-Zebu dairy cows were blocked by days in milk and randomly assigned to three 4 x 4 Latin squares. The following levels of coffee hulls were included in the concentrate portion of the diet: 0.0, 8.75, 17.5, or 26.25% of dry mater (DM). Diets were formulated to be isonitrogenous (14% CP) and contained a forage:concentrate ratio of 60:40 on DM basis. Inclusion of coffee hulls in the diet had no significant effects on intakes of DM, organic matter, CP, and total carbohydrates (TC). However, intake of neutral detergent fiber (NDF) increased linearly when coffee hulls replaced ground corn in the diet. Apparent total tract digestibilities of DM, CP, TC, NDF, and NFC all reduced linearly by increasing coffee hulls from 0.0 to 26.25% in the diet. Coffee hulls increased excretion of N in the feces resulting in a negative nitrogenous balance. The incremental levels of coffee hulls did not affect the urinary excretions of allantoin, uric acid, and purine derivatives as well as microbial protein synthesis. Milk yield and contents and yields of fat, protein, and total solids also were not affected by replacing ground corn with coffee hulls. It can be concluded that coffee hulls can be included up to 10.5% of the total dietary DM.
agroindustrial residue; chemical-bromatologic composition; concentrate diet; milk composition
