The nursing bottle nipple has a nipple portion integrally formed with an air-venting tube extending to the bottom of the bottle so that air can enter the bottle without mixing with the milk inside the bottle. An air inlet of the air-venting tube is integrally formed on the base portion of the nipple so that it cannot be covered by the collar that holds the nipple onto the neck of the bottle. A nursing bottle air-venting system is also disclosed.
