Factors that influence feed consumption in chickens include the type and age of the bird, growth and production rates, energy content and particle size of the feed, water availability, health status, ambient temperature, stress levels, and fiber content. Feed intake is higher for meat birds than layers, increases with age, and is inversely related to energy levels and particle size. Water intake depends on temperature, diet composition, and growth rate. Disease, stress, heat, poor air or litter quality can decrease consumption.