Digestive system
• The distinctive character of the mouth of the bird is the absence of lips and teeth. The tongue releases very small amount of saliva (7-30ml per day) which contains amylase enzyme.
• The crop is an enlargement of the esophagus and it is used for storing and softening the food.
• Simple stomach found in the poultry. They are divided into two parts.
Proventriculus: It is a small organ that receives food from the crop. The openings of gastric glands, present on the inner surface of the proventriculus, are secreting gastric juice and some acids.
Protein Pepsin → Peptides
Ventriculus or Gizzard in chicken:- The gizzard is heavily muscled, reddish, and located just back of the proventriculus. This organ functions chiefly in crushing and grinding food by contractions (2-5 per min.). It is the largest single organ of the body.
Small intestine: It is about 25 feet from the hangin mature bird. The inner surface is lined with villi. Besides its digestive function, the small intestine also acts as an organ or absorption feed ingredients in a simple form.
Pancreas:- It secretes a fluid known as pancreatic juice that contains Trypsin, Amylase, and Lipase enzymes. The pancreatic juice empties into the duodenum.
Liver:- This is the largest gland of the body. The liver secretes the bile. Bile is important for fat digestion.
Caeca:- At one of the small intestines are two bl sacs which are 5-7 inches in length and are called the caeca
large intestine:- It is the last part of the elementary canal short villi projected into the inner surface of the large intestine.
Cloaca:- The fecal material from the large intestine and urine from the kidney passes into this organ, The material is mixed and excreted through the vent.