Effect of methionine deficiency on small intestinal histology in Japanese quail

Japanese quail (Coturnix japonica) is a small size bird with big economical profits. This species is a good "dual-purpose" bird and is now reared for the meat and egg production. Quails have relatively early maturity and may be used as an experimental model due to their fast development, small size, etc. Moreover, because of high mortality due to emergence of new and reemergence of existing diseases in chickens, quails are being reared as they are more resistant to common poultry diseases. Methionine (Met) is a sulfur-containing amino acid with the biological functions including involvement in synthesis of eukaryotic proteins, defense against oxidative stress, methylation reactions and so on. Met also has a role in avian immune function and the nutrient digestibility in the intestine. Changes in small intestine morphology can alter absorption rate, weight gain and performance of the animal because of its important role in digestive tract for absorption. From the other point of view, alteration in the ingredients of diet may lead to a change in the intestinal mucosa and subsequently alteration in poultry performance. Thus, the aims of this study were to investigate the effect of Met deficiency on the development of the small intestine (duodenum, jejunum and ileum) and the goblet cell population in Japanese quails.

To evaluate the Met deficiency as a vital amino acid on histology of small intestine of Japanese quail, 20 male one-day old quails were randomly allocated into 2 groups of 10 birds. One group received Met deficient diet while another group of birds were kept as control with standard diet for 6 weeks. At the end of the experiment, all animals sacrificed by cervical dislocation. Whole length small intestine was removed immediately and immersed in 10% buffered formalin. After fixation, 1cm-thick samples were taken from the middle parts of duodenum (from the gizzard to pancreatic and bile duct), jejunum (from the bile duct to Meckel’s diverticulum) and ileum (from the Meckel’s diverticulum to ileo-cecal-colonic junction). After routine histological laboratory methods, 6μm-thick transverse cross-sections were made, a total number of 10 sections used from each intestinal segment of each bird; sections stained with Haematoxylin and Eosin and Periodic acid-Schiff. For measuring length and width of villi, depth of crypts and goblet cells number Axio vixion Rel 4.8 software were used. Data were expressed as Mean±SD. Data analysis was performed by Independent-Samples T Test method and differences considered statistically significant at p