Caracterização histológica de células vacuolizadas de intestino delgado de codornas (Coturnix coturnix japonica) tratadas com diferentes níveis de glicerina semi-purificada

Abstract

In recent years, commercial quail farming has become more technified for the purpose of profitable eggs, one-day-old chick raising or meat production. Feed is the largest cost item for quail production, and corn, as an energy source, presenting a very unstable price, accounts for the greatest part of the total cost of the diet. Thus, it has been trying to find alternative dietary sources of energy. Glycerin is one of them; it may be derived from natural sources as well as from petrochemical industry; it presents low market value and it has high intestinal absorption rate. Small intestine is divided into three parts: duodenum, jejunum and ileum, and its layers are formed by tunica mucosa, tunica muscularis, tunica serosa and lamina propria. It presents microvilli, whose epithelium is formed by columnar, caliciform and vacuolated cells. Vacuolated cells migrate along the crypts towards the villi and part of these cells differentiates into enterocytes. Thus, the aim of our study was to evaluate the vacuolated cells proliferation and differentiation dynamics in the three parts of the small intestine under direct influence of a diet with different levels of semi-purified glycerin in replacement of corn and its potential on intestinal maturation of male quails. We used 955 male quails divided into five treatments, with different levels of increasing semi-purified glycerin in the diet: 0%, 5%, 10%, 15% and 20%. Quails were slaughtered and their small intestine was fixed in formaldehyde, prepared for histology, stained with PAS and the images were analyzed using 100 and 400x magnification. We could observe that small intestine vacuolated cells disappeared since the first week of treatment in animals that received increasing levels of glycerin. Studies have proved that glycerin in the diet increases IGF-I plasmatic concentration, suggesting its influence on vacuolated cells disappearance for enterocyte differentiation. Including glycerin in the diet from an economic point of view may be an advantage, because feed cost decreases and there is an increase in the efficiency of nutrient absorption by the intestine.