Fibra dietética associada ou não a probiótico em dietas para leitões desmamados

Abstract

This thesis work consisted of 3 experimental essays. The first presents a systematic review of studies that investigated the role of fiber in the diet of weaners and its influence on intestinal integrity and immunological markers. After using exclusion and inclusion criteria, the database consisted of 24 originals studies. It was observed that most of the articles used up to 100 animals to carry out the experiments and that the most common age for weaning was at 28 days. In several articles, it was possible to prove the effectiveness of fiber, depending on the source and level used, in the maintenance and improvement of intestinal integrity and barrier function. This research may have elucidated some important parameters when starting a field experiment. In the second trial, the objective was to carry out a a meta-analysis of the relationship between dietary fiber and the performance of piglets in the weaning phase. Through online searches in different indexing bases, a total 8360 articles were exported to the software for later selection. Graphical analyzes for to general evaluation of the data and to obtain an evalution of their consistencyand heterogeneity. Means were compared using Tukey’s test at 5% probability using the Minitab 20 program. After using exclusion and inclusion criteria, the database consisted of 57 original studies, from 18 countries and published between 1997 and 2020 in 26 different journals. Almost half of the articles were published from 2015 onwards and the most common level of NDF was recommended. Even with great variability in the data, it was possible to verify that in studies with crude fiber levels between 4 and 5%, the animals showed greater relative daily weight gain, while there was no explicit correlation between a higher level of NDF and an increase in feed intake. There was an effect (P<0.05) of the NDF on feed efficiency, in which the animals that consumed the low level had better values when compared to those that consumed the high level. A trend towards greater weight gain was observed in studies that used low and recommended levels of NDF. This study may serve as a basis for future work, based on the researched data. In the third trial, the objective was to evaluate the effects of adding lignocellulose associated or not to probiotics in diets for weaned piglets. Forty weaned piglets of the same commercial strain were used 20 castrated males and 20 females. The animals were distributed in an experimental desing in randomized blocks, with four treatments and five replications. The treatments were arranged as follows: CD: control diet composed mainly of corn and soybean meal; DF: CD + 1% of lignocellulose; PD: DC + 0.2% of probiotic; FPD: DC + 1% of lignocellulose and 0.2% os probiotic. The addition of lignocellulose and probiotic did not affect (P>0.05) performance or diarrhea incidence. There was an effect (P<0.05) of the experimental diets for the analysis of serum immunoglobulins, in which for IgG and IgM animals that consumed FPD had higher levels followed by PD, DF and CD, respectively; for IgA the consumption of the DFP diet increased the levels. Piglets that consumed diets containing lignocellulose and probiotics in association or not showed higher (P<0.05) villus height (VH) in the duodenum and ileum, and lower crypt depth and better ratio in the jejunum. The VH in the jejunum was higher for animals that consumed the FPD. Fecal butyrate profiles were higher (P<0.05) in piglets that consumed the DF and PD diets and the valerate level increased (P<0.05) from the consumption of the PD diet. In conclusion, the use of 1% of lignocellulose and 0.2 % of probiotic in association or not can be recommended because it increases serum antibodies, short-chain fatty acid profiles, in addition to improving morphometric parameters. Intestinal tract, without prejudice to performance variables, digestibility nutrients and the incidence of diarrhea.