Avaliação histológica do trato gastrointestinal de cordeiros alimentados com dietas alto grão

Abstract

The objective of this study was to evaluate histological parameters of the rumen and small intestine of confined lambs receiving a high-grain diet, with different processing of corn grain. 24 male lambs, ½ Dorper blood, with an initial average age of 70 days, and an initial average body weight of 15±2 kg were used. A randomized block experimental design was used, with three treatments and eight replications each. The treatments were formed based on the different processing of the corn grain, as follows: T1= whole corn grain (GMI); T2= coarsely ground corn grain, on a 2mm sieve (GMG); T3= finely ground corn grain represented by three different corn grain processing (GMF), on a 6 mm sieve. The data obtained were subjected to the Shapiro-Wilk normality test, and the comparison of treatment means was carried out using ANOVA, followed by the Tukey test, when the data presented normality, or the Kruskal Wallis test, followed by the Dunn when they were not normal, at 5% probability, using the statistical program biestat 5.0. The morphometric analyzes of the rumen, muscle layer thickness and epithelium thickness showed no significant difference between treatments (P > 0.05). Papilla height and papilla width showed a significant difference (P < 0.05) between the GMG and GMF treatments. The papilla area was larger (P < 0.05) in the GMF treatment compared to the others, with an average value of 893018.5414 µm. For the small intestine portion, there was no significant difference in mucosal thickness (P > 0.05). For the submucosal thickness, it was greater (P < 0.05) for the treatment, differing from the GMF treatment, 528.60 µm. For goblet cells, the GMF treatment obtained the highest average, 34.50 µm, with a significant difference (P < 0.05) between the other treatments, GMI and GMG. The different types of corn grain processing did not present deleterious changes in the histological parameters of the rumen and small intestines evaluated, so that either the whole corn grain or those processed, emphasizing the GMF treatment, can be used without compromising the absorption of nutrients throughout the gastrointestinal tract.