Histomorphology and proteolytic activity in the gastric apparatus of frugivorous, carnivorous and omnivorous species of birds.
The histomorphology of the gastric apparatus, the pepsin level and the optimum pH for pepsin were investigated in Psittacula krameri (frugivore), Lanius schach (carnivore) and Acridotheres tristis (omnivore) species of birds. The proventricular glands were found to be made up of oxynticopeptic cells. The lobules of the oxynticopeptic cells are polyhedral; they are the largest in P. krameri, and the smallest in A. tristis. However, their greater number in A. tristis enables a higher secretion of hydrochloric acid and pepsin. The villi are more developed in A. tristis than in L. schach and P. krameri. The gizzard is larger in A. tristis than in P. krameri and A. tritis than in the carnivore L. schach. Koilin lining is beset with horny cones, which were well developed in A. tristis, moderately developed in P. krameri and absent in L. schach. The pepsin activity is higher in the proventriculus of the carnivorous L. schach and the omnivorous A. tristis than in the frugivorous P. krameri. Slight pepsin activity was also observed in gizzard tissue extracts in all the three species. The optimum pH for pepsin was found to be 1.5 for P. krameri and 1.8 for both L. schach and A. tristis.
D000818:Animals; D001717:Birds / Q000033:anatomy & histology* / Q000378:metabolism; D004032:Diet; D004064:Digestive System / Q000033:anatomy & histology / Q000201:enzymology; D005895:Gizzard, Avian / Q000033:anatomy & histology; D006863:Hydrogen-Ion Concentration; D010434:Pepsin A / Q000378:metabolism*
D010434:Pepsin A