A method for monitoring food intake of livestock animals includes defining a relationship between time an animal spends at a feeding trough and the animals food intake during that time, monitoring the time an animal spends at the feeding trough and determining a quantity of food intake for the animal based on the time spent at the feeding trough and the defined relationship. Optionally, time an animal spends in a feeding position at the feeding trough is monitored and used to determine quantity of food intake.