This study aimed to determine the effect of the addition of oat hull (0–3%) and high amounts of cereal grains to the diet of broiler chickens in terms of the development of the upper gastrointestinal tract, individual microbial counts in the crop and ileum, and the effect of dietary fibre fractions on microbial changes from the beak to the ileum. In the 28 d trial, 162 one-day-old Hubbard Flex male chickens with an average body weight of 44.5 g were randomly allocated to 27 metabolic cages. The experiment consisted of a randomised, one factorial ANCOVA design composed of a covariate with two ANOVA factorial designs containing nine treatments (3 × 3): three sources of cereal grains (maize, wheat, and barley, with a minimum amount of 500 g · kg⁻¹, each with nine replications) and three levels of oat hull (0, 1, and 3%, each with nine replications). At the end of the study, 81 chickens (9 in each treatment) were slaughtered to determine the weight of the individual organs and characterise the intestinal microbiota. The application of 3% oat hull to the cereal diets increased the weight of the proventriculus and the gizzard (6.3 and 27.3 g, respectively) in comparison to diets without the addition of this structural component (6.0 and 23.7 g). Higher crop counts of total aerobic microbes (6.29 log CFU · g⁻¹) and Lactobacillus spp. (4.05 log CFU · g⁻¹) were observed in diets containing wheat grain compared with maize (4.62 and 3.55 log CFU · g⁻¹, respectively). The main reason for the microorganism’s growth (p < 0.05) was the amount of soluble dietary fibre and hemicelluloses present in the diet: total aerobic microbial count (respectively r = 0.918 and r = 0.816) and Lactobacillus spp. (respectively r = 0.416 and r = 0.442). Barley diets decreased (p < 0.05) E. coli counts in the ileum (2.69 log CFU · g⁻¹) vs. maize and wheat diets (3.41 and 3.45 log CFU · g⁻¹, respectively), mainly due to the increase in the amount of insoluble dietary fibre in the diet (r = −0.462). Reduced total yeast and mould counts in the ileum were also observed (p < 0.05) in connection with the presence of soluble dietary fibre and hemicelluloses in diets (r = −0.397 and −0.398, respectively).

The purpose of the experiment was to determine the effect of oat hull on the performance and morphometric measurements of the gastrointestinal tract, and to correlate the results of these measurements with the type of the determined dietary fiber in feed and the number of microorganisms. The Asp method is simpler and quicker than non-starch polysaccharide analysis, and can give quick information in the analysis of fiber fractions (soluble and insoluble) in the component or in a diet, and also related the obtained results with the performance of broiler chickens. The utilization of oat hull in the amount of 1% of the diet of broiler chickens results in the highest body weight on the 28th day of life (p < 0.05) in comparison to the group not receiving oat hull in the diet and with a 3% share of this structural component. Oat hull in the diet of broiler chickens in the amount of 1% also reduces the total length of the intestines (p < 0.05), compared with the share of 0 and 3%. The soluble fiber contained in the grains of barley and wheat has an influence on the higher metabolic weight of the glandular stomach of broiler chickens compared to the birds receiving corn grain in their diet. Barley grain and oat hull in the amount of 3% significantly (p < 0.01) increase the weight of gizzards. The increase in the weight of the proventriculus (r = 0.392), gizzard (r = 0.486) and duodenum (r = 0.657) was positively correlated with the growth of E. coli bacteria in the crop. The opposite effect in the case of negative correlation was determined in the case of the duodenum and E. coli count (r = −0.593).

Dietary fibre is an important nutrient present both in roughage and concentrates for horses. On the one hand, it plays a key role in processes related to the motility of the gastrointestinal tract. On the other hand, its decomposition within the cecum and colon is a source of energy for a horse. This energy is more readily available as soluble fractions in such components increase, mainly pectin. Hence, components such as dried beet pulp, soy hull or dried citrus pulp are classified as sources of the so-called ‘super fibre’ because of the high soluble fraction. The fibre composition analysis in mixtures is carried out using three different methods. In Poland, sugar beet pulp is a common component with a high content of soluble structural carbohydrates. Due to the gastrointestinal tract structure in horses, it is appropriate to use dried sugar beet pulp due to the low risk of fungal and moulds contamination. Additionally, they are proper for animals with gastrointestinal problems because metabolites formed during fibre degradation affect the regeneration of intestinal epithelium. Their application as one of the components affects the effective use of excess protein present in the diet for animals, which is especially important in horses with kidney or liver diseases. This review describes the importance of the dietary fibre fraction and the benefits resulting from the use of feed components called super fibre, with particular emphasis on dried sugar beet pulp and their impact on the gastrointestinal health of horses.

Regulation of the diet in terms of the content of soluble and insoluble fibre is of great importance from the point of view of dietetics, microbiology of the gastrointestinal tract and immunology of the organism. Dietary fibre plays an important role in maintaining the balance between the con-tinuity of gut mucus production (intestinal mucosa), the stability of the intestinal microbiome composition, the regeneration of the intestinal epithelium and the immune status within the gut-associated lymphoid tissue (GALT) are played by pectin and their metabolic products in the form of pectin oligosaccharides. The main purpose of this review was to focus on pectin, their functions, their impact on the human's health and on some of the most promising prebiotics due to their solubility in the gastrointestinal tract in the form of pectin oligosaccharides. They have the properties of pectin, but have also additional features and postbiotics obtained in fermentation process can affect the intestinal microbiome and GALT-related immunity. They can be obtained from plant agro-wastes.

The purpose of the research was to determine the effect of the use of a diet containing 30% triticale grain. In an experiment lasting 28 days, 180 one-day Ross-308 chickens (sex ratio 1:1) with an average initial body weight in treatment of 44.6 g were randomly assigned to 30 metabolic cages/replications, 6 birds in each. To compare the results between treatments, a one-way ANOVA was used with uneven replication numbers. The control group (I) received a standard diet containing maize and soybean meal. In the other treatments, 30% of different cereals were used: II—wheat, III—barley, and IV—triticale. Significant differences in body weight (BW) and feed conversion ratio (FCR) were observed on the 4th day of the life of broiler chickens (p < 0.05). Differences were determined between the control group (90.7 g BW and 1.32 kg of feed/kg BWG in the case of FCR) and birds receiving barley (93.0 g BW and 1.29 kg of feed/kg BWG in the case of FCR), compared to chickens fed diets with a 30% share of wheat grain (86.2 g BW and 1.53 kg feed/kg BWG in the case of FCR) and triticale (86.6 g BW and 1.53 kg feed/kg BWG in the case of FCR). Later, the differences in performance of birds between treatments did not occur (p > 0.05). In the nutrition of broiler chickens, control or 30% of the triticale diet caused a significant reduction (p < 0.01) of the number of Escherichia coli (E. coli) in the crop of broiler chickens (0 log cfu/g), compared to birds obtaining feed with 30% of wheat (1.78 log cfu/g). The diet containing triticale also reduced the number of E. coli (p < 0.05) within the ileum (0.78 log cfu/g) compared to chickens obtaining barley grain in the diet (2.12 log cfu/g). As a result of the use of triticale grain (p < 0.05), the total length of the bird intestines (199.64 cm) was compared to 30% of barley grain (209.76 cm). The increase in the length of the large intestine of broiler chickens in treatments was positively correlated (r = 0.613, p < 0.05) with the number of Lactobacillus sp. in the ileum. Triticale increased the pH in the crop of broilers chickens. The research results indicate that triticale, after longer storage, can be used in amounts of 30% of the diet without significant effect on the performance of broiler chickens, with a reduction in E. coli in crop in comparison with wheat and in ileum with barley.

The objective of this study was to compare the effects of applying a 50% wheat grain diet with those of a diet with 3% additional dietary fibre from various sources on the development of broiler chickens’ gastrointestinal tract and its related organs and to model this phenomenon based on data obtained from 35-day-old chickens using multiple regression equations. The use of various structural components, including oat hull (OH), sunflower hull (SH), sugar beet pulp (SBP), and wheat bran (WB), in proportions of 3% of the diet not only affects digestive processes in broiler chickens’ gastrointestinal tract but also causes a change in the length of their intestinal sections or the weight of related organs. These effects can be taken into account when creating an experimental model, the results of which can at least be partially applicable to human studies. The use of OH and SH (3%) in the birds’ diets resulted in a significantly higher body weight (p < 0.05) compared with the use of SBP and WB. OH in the diet significantly increased (p < 0.01) the weight of the chicken’s gizzards compared with the other dietary fibre sources, apart from SH. On the other hand, the weight of the proventriculus in chickens fed the diet containing OH was significantly lower than that of the chickens fed the diet containing SBP (p < 0.05). The use of SH in the diet caused a significant decrease (p < 0.01) in the weight of the chickens’ heart. Compared with other additional sources of dietary fibre, OH in the diet also significantly increased (p < 0.05) the lengths of the small and large intestines, as well as the total length of the intestines. A correlation analysis showed a significant, average, positive relationship (p < 0.05) between the content of TDF in the diet and the weight of the gizzard and indicated a significant positive correlation between the lengths of the jejunum and the remaining sections of the intestines. Additionally, the regression equation models indicated a significant effect (p < 0.01) of all the independent variables on the jejunal, ileal, and caecal lengths and the liver weight. The application of the regression model confirmed significant changes in the small intestine and liver weight depending on the type of dietary fibre and other independent variables, which can also be taken into account when assessing diseases in people with thin intestines. However, further studies with separate models still need to be conducted using experiments including both soluble and insoluble fibre.