If you are tube feeding calves it is important you know how to place the tube correctly to deliver the milk into the oesophagus (path to stomach) and not into the lungs. If you have milk coming out of the calf’s mouth and or nostrils whilst you are tube feeding, your tube is NOT correctly placed, and / or the calf is not correctly positioned. 
 
The diagram here of the Antahi Trusti Tuber shows the correct position of the tube. It is in the oesophagus (has been swallowed by the calf) and is sitting towards the base of the neck. Antahi have created a great video resource which shows the important steps in tubing. https://www.youtube.com/watch?v=51oCJbgT9O8