Stability of milk from dual purpose cows with different types of feeding

Objective: To establish milk stability using the alcohol test in cows with different feeding strategies in the tropical dairy system.Design/methodology/approach: Ten crossbred Holstein  Zebu cows whose milk frequently tested positive to the alcohol test were housed in individual yards and distributed into two groups. Experiment 1. T1: cows consumed dry Pangola grass (Digitaria eriantha); T2: cows consumed green Maralfalfa grass (Pennisetum violaceum). Forage was provided ad libitum. Experiment 2. T1 cows were supplemented with a concentrate with higher crude protein and metabolizable energy percentage than T2 cows; this percentage was gradually increased up to 4.0 kg. Milk was subjected to alcohol testing. Variance analyzes were performed under categorical data models.Results: Higher percentages of cases that tested positive for alcohol were observed in cows that consumed dry grass than in cows that consumed green grass (P0.05). The concentrate addition to diets based on dry or green forage reduced the positive case percentage.Implications: A balanced diet improves milk stability.Findings/conclusions: The improvement in the cows’ nutritional value decreases the percentage of milk with positive results in the alcohol test.