Quote:
FYI...sorry, but nothing is "ground up" in the
crop ...The crop stores food temporarily and allows food to be (somewhat) softened (but not digested) before it enters the "stomach".....
http://www.poultryhub.org/index.php/Digestive_system
(an excellent article >here below some excerpts:
"....Summary of digestion and metabolism
The utilisation of nutrients from the diet is a key element in the normal functioning of the animal. The avian digestive system is a simple system and consequently the diet must be of good quality
and consist of easily digested ingredients if the bird is to perform at the level required .....
.....factors affect the rate of movement of the food through the digestive system with a meal of normal food taking approximately 4 hours to pass through in the case of young stock, 8 hours in the case of laying hens and 12 hours for broody hens. Intact, hard grains take longer to digest than the cracked grain and, quite often some whole grain will pass through unchanged.......
Food storage
The food is delivered into the crop for
storage after the first few boli have passed into the proventriculus. The crop is quite distensable and will hold a large amount of undigested food that is then moved on as required by the proventriculus (glandular stomach)......
Enzyme action
After ingestion, the food is mixed with saliva and mucous from the mouth and oesophagus and these secretions thoroughly moisten the food. The enzyme amylase, which is produced by the salivary and oesophageal glands and found in the saliva and mucous, can now commence to breakdown the complex carbohydrates. However,
the amount of enzyme action at this stage is minimal and the first major enzyme activity takes place in the proventriculus and in the gizzard. ..............
....Breaking the food particles
The gizzard is a very powerful organ with the function of physically breaking the food particles into smaller sizes to make the work of the enzymes easier. At the same time the enzymes previously released into the food with the saliva and by the proventriculus are thoroughly mixed into the food thus improving their opportunity to carry out their work. This breaking and mixing function of the gizzard is enhanced by the presence of insoluble grit such as stones....."