The objective of this work was to evaluate theinclusion of anionic salt in the diet on the physical characteristics and chemicalcomposition of milk, biochemical blood profile, milk yield, body weight andcondition. It was used 20 Jersey cows, distributed into two diets, a diet withno addition of anionic salt and one diet with addition of 0.25 kg/day of ammoniumchloride. It was used a completely randomized design. Cows supplemented withanionic salt presented lower urinary pH and increase of blood contents of urea,calcium and magnesium. With the anionic diet, milk precipitated with lower ethanolconcentration and it presented lower density, percentages of lactose, proteinand immunoglobulin, but higher ionic calcium content. Supply of anionic dietduring lactation resulted in metabolic acidosis, which altered the blood biochemicalprofile and milk physical-chemical characteristics.