No she is eating well just had sex with male bill a day before

Pregnancy is the likely reason for the milk drop. After mating, some buffaloes show a small fall in milk for a few days. Keep her on normal good feed, clean water, and calm housing. Do not overmilk or stress her. Watch for heat again, discharge, or off-feed signs. If milk keeps falling for more than a week, or she stops eating, get her checked for early pregnancy or uterine trouble.