Abstract The objective of this work was to determine the effect of inclusion levels of dietary fiber in the Japanese quail diets. 480 Japanese quail were distributed in a completely randomized design, with 5 treatments and 12 replicates composed of 8 birds each. The treatments were constituted by five increasing levels of fiber in the diet: 2.78; 3.08; 3.38; 3.68; 3.98%. The parameters of productive performance, water consumption, egg quality, total lipids in the egg, excreta humidity, weight of digestive organs and intestinal morphology were evaluated. There was no significant effect of the use of different fiber levels on feed intake, egg production, viability, live weight, relative and absolute weight of gizzard, small intestine and cecum, and in excreta moisture of Japanese quais. Higher dietary fiber levels resulted in improvements in feed conversion per mass and per dozen eggs and higher water consumption. There was no significant difference for egg quality, except fot the color of the yolk where it was observed higher pigmentation of this structure with higher levels of fiber inclusion, and the lipid concentration in the buds was influenced in a quadratic manner. The inclusion of fiber promoted improvement in the villi of the duodenum and cecum.

Abstract This study aimed to evaluate the intestinal morphology, performance and financial analysis of the inclusion of additives in the feed during the productive period of 360 Japanese quails distributed in a completely randomized design in a split plot scheme in time with five treatments and eight repetitions of nine birds each. The treatments were: control, antibiotic, prebiotic, probiotic and synbiotic. The variables were: height, width and width/height ratio of the villi, crypt depth and villus/crypt ratio, feed intake, egg production, egg weight average, egg mass, feed conversion per mass and per dozen eggs and viability, internal rate of return, net present value and cost benefit. The additives in the feed increased height and width of the villi, decreased crypt depth and increased villus/ crypt ratio compared to the control. Feed intake was lower after the inclusion of antibiotics and synbiotics in the feed. Egg production and feed conversion improved after the inclusion of additives in the feed compared with the control. The reduction of feed intake was more pronounced with the addition of antibiotic and synbiotic in the final stage of the productive period of the Japanese quails. The inclusion of antibiotics and synbiotic proved to be more financially viable.