Digestibility and energy value of non-starch polysaccharides in young chickens, ducks and geese, fed diets containing high amounts of barley

Response of laying hens fed diet supplemented with a mixture of olive, laurel, and rosemary leaf powders: Metabolic profile, oxidative status, intestinal histomorphology, and egg quality

This study aimed to evaluate the effects of a mixture of olive, laurel, and rosemary leaf powders, on the oxidative state, biochemical, immune, intestinal morphophysiological parameters, and egg quality of laying hens. One hundred Lohmann Brown hens (28 weeks old) were equally assigned to two groups (n. 50) corresponding to a basal control diet (CON) or the diet supplemented with 6 g/kg feed of leaf powder mixture (LPM) containing olive, laurel, and rosemary leaves (1:1:1), for 60 days. Oxidative status, biochemical indices, immune response, cecal short chain fatty acids (SCFAs), intestinal morphological characteristics, and some egg traits were evaluated at the end of the experiment. The results indicated that LPM improved (P < 0.05) the oxidative status (TOS, ROMs), the immune system (IL-6, IL-1β, and TNF-α), the total protein and HDL cholesterol content, whereas it decreased (P < 0.05) total cholesterol and LDL cholesterol. Aspartate aminotransferase (AST), alkaline phosphatase (ALP), and alanine aminotransferase were significantly (P < 0.05) lower in the LPM than in the CON group. A significant increase (P < 0.05) in SCFA content in the caecum, as well as in villi height and crypt depth in both duodenum and ileum of LPM-treated hens, was observed. Egg quality parameters were not influenced (P > 0.05) by LPM. These findings indicate that LPM can be considered a candidate as an antioxidant ingredient for functional food in laying hens.

Effect of Triticale Grain in Diets on Performance, Development of Gastrointestinal Tract and Microflora in Crop and Ileum of Broiler Chickens

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.

Effect of Oat Hull as a Source of Insoluble Dietary Fibre on Changes in the Microbial Status of Gastrointestinal Tract in Broiler Chickens

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).

Cecal Microbial Hydrogen Cycling Potential Is Linked to Feed Efficiency Phenotypes in Chickens

In chickens, early life exposure to environmental microbes has long-lasting impacts on gastrointestinal (GI) microbiome development and host health and growth, via mechanisms that remain uncharacterized. In this study, we demonstrated that administrating a fecal microbiome transplant (FMT) from adults to day-of-hatch chicks results in significantly higher body mass of birds and decreased residual feed intake (RFI), implying enhanced feed efficiency, at 6 weeks of age. To assess the potential mechanisms through which FMT affects adult bird phenotype, we combined 16 S rRNA gene amplification, metagenomic, and comparative genomic approaches to survey the composition and predicted activities of the resident microbiome of various GI tract segments. Early life FMT exposure had a long-lasting significant effect on the microbial community composition and function of the ceca but not on other GI segments. Within the ceca of 6-week-old FMT birds, hydrogenotrophic microbial lineages and genes were most differentially enriched. The results suggest that thermodynamic regulation in the cecum, in this case via hydrogenotrophic methanogenic and sulfur-cycling lineages, potentially serving as hydrogen sinks, may enhance fermentative efficiency and dietary energy harvest capacity. Our study provides a specific mechanism of action through which early-life microbiome transplants modulate market-relevant phenotypes in poultry and, thereby, may represent a significant advance toward microbiome-focused sustainable agriculture.

Microbial short-chain fatty acids: a bridge between dietary fibers and poultry gut health

The maintenance of poultry gut health is complex depending on the intricate balance among diet, the commensal microbiota, and the mucosa, including the gut epithelium and the superimposing mucus layer. Changes in microflora composition and abundance can confer beneficial or detrimental effects on fowl. Antibiotics have devastating impacts on altering the landscape of gut microbiota, which further leads to antibiotic resistance or spread the pathogenic populations. By eliciting the landscape of gut microbiota, strategies should be made to break down the regulatory signals of pathogenic bacteria. The optional strategy of conferring dietary fibers (DFs) can be used to counterbalance the gut microbiota. DFs are the non-starch carbohydrates indigestible by host endogenous enzymes but can be fermented by symbiotic microbiota to produce short-chain fatty acids (SCFAs). This is one of the primary modes through which the gut microbiota interacts and communicate with the host. The majority of SCFAs are produced in the large intestine (particularly in the caecum), where they are taken up by the enterocytes or transported through portal vein circulation into the bloodstream. Recent shreds of evidence have elucidated that SCFAs affect the gut and modulate the tissues and organs either by activating G-protein-coupled receptors or affecting epigenetic modifications in the genome through inducing histone acetylase activities and inhibiting histone deacetylases. Thus, in this way, SCFAs vastly influence poultry health by promoting energy regulation, mucosal integrity, immune homeostasis, and immune maturation. In this review article, we will focus on DFs, which directly interact with gut microbes and lead to the production of SCFAs. Further, we will discuss the current molecular mechanisms of how SCFAs are generated, transported, and modulated the pro-and anti-inflammatory immune responses against pathogens and host physiology and gut health.

Dietary Soluble Non-Starch Polysaccharide Level Influences Performance, Nutrient Utilisation and Disappearance of Non-Starch Polysaccharides in Broiler Chickens

This study evaluated the effect of dietary soluble non-starch polysaccharides (sNSP) on performance and nutrient utilisation in broilers from d 0 to 35. Cobb 500 broilers (n = 480, 80 birds per treatment) were fed either wheat- or corn-soybean meal-based diets formulated to contain either a high, medium, or low sNSP content, in a 2 × 3 factorial arrangement, fed as Starter (d 0−14) and Grower (d 14−35). Birds fed the low sNSP level presented greater BWG at d 0−14 and lower feed intake at d 14−35 compared to birds fed the medium sNSP level (p < 0.005). At d 14, birds fed the high sNSP level presented greater ileal and total tract starch digestibility and total tract sNSP degradability and insoluble NSP degradability, compared to feeding the low sNSP level. At d 35, total tract DM and metabolisability of gross energy was greater in birds fed the medium sNSP level compared to those fed the high or low sNSP level (p < 0.005). Generally, bird performance and nutrient utilisation was greater in birds fed the corn-based diets compared to the wheat-based diets. These results illustrate that dietary sNSP level and composition influences bird performance and nutrient digestibility.

Effect of Olive Leaves or Marigold Petal Extract on Oxidative Stress, Gut Fermentative Activity, and Mucosa Morphology in Broiler Chickens Fed a Diet Rich in n-3 Polyunsaturated Fats

An experiment in broilers was conducted to investigate the effect of olive (Olea europea) leaves and marigold (Calendula officinalis) petal extract supplementation on oxidative stress, characteristics of intestinal contents, and on the morphology of the small intestine. Oxidative stress was induced by a n-3 polyunsaturated fatty acids rich diet. 1-day-old male broiler chickens, Ross 308, were housed in a deep litter system. After the first 21 days, animals were randomly divided into three groups of 16 animals in two replicates and fed, until slaughter on day 39, a diet that contained 7% linseed oil. Control diet (Cont) remained unsupplemented, while both experimental diets were supplemented with olive leaves (OliveEx) or marigold petal (MarigEx) extracts. Oxidative stress was evaluated in blood and liver by measuring markers of lipid peroxidation (malondialdehyde (MDA), isoprostanes), rate of DNA damage in lymphocytes and in blood (comet assay, 8-hydroxy-2'deoxyguanosine (8-OHdG)), and activity of antioxidant and liver enzymes in blood. In different parts of the intestine, levels of short chain fatty acids (SCFA), and viscosity of intestinal contents were measured, and the health of the gastrointestinal tract was assessed using histological measurements. OliveEx significantly (p<0.05) decreased the MDA and 8-OHdG concentration in plasma, and the level of ethanoic acid in small intestinal contents and total SCFA in caecum, indicating improved oxidative status and increased microbial activity in the intestine. MarigEx significantly (p<0.05) decreased the rate of lymphocyte DNA damage and the crypt depth in duodenum, indicating potentially beneficial effects on the immune system and the health of the small intestine. In conclusion, dietary OliveEx and MarigEx supplementation improved some markers of oxidative stress and intestinal health. However, positive effects could be more pronounced in more unfavorable environmental conditions or in cases of diseases, but further studies are needed.

The effect of delayed feeding post-hatch on caeca development in broiler chickens

1. Broiler chicks are frequently deprived of food up to 72 h due to uneven hatching rates, management procedures and transportation to farms. Little is known about the effect of delayed feeding due to extended hatching times on the early neonatal development of the caeca. Therefore, the objective of this study was to investigate the developmental changes and effects of a 48-h delay in feed access immediately post-hatch (PH) on the caeca.2. After hatch, birds (Ross 708) were randomly divided into two treatment groups (n = 6 battery pen/treatment). One group (early fed; EF) received feed and water immediately after hatch, while the second group (late fed; LF) had access to water but had delayed access to feed for 48 h. Contents averaging across all regions of the caeca were collected for mRNA expression as well as for histological analysis at -48, 0, 4 h PH and then at 1, 2, 3, 4, 6, 8, 10, 12 and 14 days PH.3. Expression of MCT-1 (a nutrient transporter), Cox7A2 (related to mitochondrial function) IgA, pIgR, and ChIL-8 (immune function) genes was affected by delayed access to feed that was dependent by the time PH. Expression of immune and gut barrier function-related genes (LEAP2 and MUC2, respectively) was increased in LF group. There was no effect of feed delay on expression of genes related to mitochondrial functions in the caeca, although developmental changes were observed (ATP5F1B, Cox4|1). Caecal mucus and muscle thickness were affected by delayed access to feed during caeca development.4. The data suggested a limited effect of delayed feed access PH on the developmental changes in caecal functions. However, the caeca seemed to be relatively resistant to delayed access to feed early PH, with only a few genes affected.

Effects of dietary barley inclusion and glucanase supplementation on the production performance, egg quality and digestive functions in laying ducks

This study evaluated the effects of barley inclusion and glucanase supplementation on the productive performance and digestive function in laying ducks. The experiment used a randomized design with a 5 × 2 factorial arrangement of 5 graded levels of barley (0%, 15%, 30%, 45% and 60%) with or without 1.5 g/kg β-1,3-1,4-glucanase (15,000 U/kg). During the experimental period of 120 d, the weight and total number of eggs within each pen were recorded daily, and egg quality was determined every 4 wk. At the end of the experiment, 3 randomly selected ducks within each replicate were sacrificed, then duodenal digesta and jejunal mucosa was collected. Dietary inclusion of barley had no effects on egg production, daily egg mass or FCR, but supplementation with glucanase improved egg production and FCR (P < 0.01). Barley did not affect feed intake of laying ducks, but glucanase tended to increase feed intake (P = 0.09). Neither barley nor β-glucanase had effects on the egg quality variables, except for yolk color score, which was decreased with increasing barley supplementation. Glucanase, but not barley, increased the activity of chymotrypsin and amylase in duodenal digesta. Barley inclusion affected the activity of alkaline phosphatase and maltase in jejunal mucosa (P < 0.05), but β-glucanase had no effects on the activity of these brush border enzymes. Barley inclusion increased the glucan content in duodenal digesta, but supplementation of glucanase to barley-based diet reduced digesta glucan content and reduced total volatile fatty acids and increased the proportion of acetic acid in cecal contents. The results indicate that, without glucanase, the optimal dietary barley level in the diets of laying ducks is about 13% for maximal production performance; glucanase supplementation of the barley diets improved production performance, probably through enhancing digestive function.

Synergistic effect of exogenous multi-enzyme and phytase on growth performance, nutrients digestibility, blood metabolites, intestinal microflora and morphology in broilers fed corn-wheat-soybean meal diets

OBJECTIVE

This study was conducted to investigate the synergistic effect of exogenous multienzyme and phytase on growth performance, nutrients digestibility, blood metabolites, intestinal microflora, and morphology in broilers fed corn-wheat-soybean meal diets.

METHODS

A 2×2 factorial design was used in this study. Four dietary treatments consisted of i) basal diets (corn-wheat-soybean meal based diets without multi-enzyme and phytase), ii) basal diets with phytase (0.05%), iii) basal diets with exogenous multi-enzyme (0.05%), and iv) basal diets with exogenous multi-enzyme including phytase (0.05%). A total of 480 broiler chickens (Ross 308 - one day old) were weighed and allotted to thirty-two cages (15 birds per cage), and chicks were randomly allocated to four dietary treatments.

RESULTS

The body weight gain and feed conversion rate were improved by supplementation of exogenous multi-enzyme containing phytase during the finisher period (p<0.05). The birds fed diets with exogenous multi-enzyme containing phytase had a significantly greater digestibility of dry matter, gross energy, crude protein, calcium, and phosphorus compared with birds fed non-supplemented diets (p<0.05). The chickens fed diets with exogenous multi-enzyme containing phytase showed a higher concentration of Ca and P in the serum (p<0.05). The population of Lactobacillus spp., Escherichia coli, and Clostridium were not affected in the ileum and cecum of chickens fed enzyme-supplemented diets. The dietary supplemental exogenous multi-enzyme containing phytase showed a significant improvement in villus height, crypt depth, and villus height and crypt depth ratio, compared to basal diets or dietary supplemental phytase (p<0.05).

CONCLUSION

The supplementation of the exogenous multi-enzyme containing phytase synergistically improved the growth performance, nutrients digestibility, and villus height of the small intestine of broiler chickens fed a corn-wheat-soybean meal based diets.

Effects of Soy Protein Concentrate in Starter Phase Diet on Growth Performance, Blood Biochemical Indices, Carcass Traits, Immune Organ Indices and Meat Quality of Broilers

Soybean meal (SBM) is high in antinutritional factors (ANFs), which is not conducive to the starter growth of broilers. The purpose of this study was to investigate the effects of soy protein concentrate (SPC) in starter diet on growth performance, carcass traits, meat quality, immune organ indices and blood biochemical indices of broilers. A total of 384 1-day-old Arbor Acres (AA) male broilers (46.05 ± 0.37 g) with similar body weight were randomly divided into 4 groups with 8 replicates in each group and 12 broilers in each replicate. The experiment was divided into three phases: in starter phase (1-10 d), birds were fed a corn-SBM-based basal mash diet (control) and the basal diet was supplemented with SPC at 4% (SPC4), 8% (SPC8), 12% (SPC12). In the grower phase (11-21 d) and the finisher phase (22-42 d), the birds in all four treatment groups were fed the same diets. The results showed that the body weight was significantly increased in the SPC8 and SPC12 groups of broilers at 10 d and 42 d (p < 0.05). The average daily gain was significantly increased in the SPC12 group of broilers at 1-10 d and 1-42 d (p < 0.05). The average daily feed intake was significantly increased in the SPC8 and SPC12 groups of broilers at 1-10 d (p < 0.05). The feed conversion rates at 1-42 d (p = 0.055) tended to decline in the SPC12 group. The carcass yield and the thymus indices were significantly increased in the SPC12 group of broilers at 42 d (p < 0.05). Alanine aminotransferase (ALT)/ aspartate aminotransferase (AST) tended to decline in SPC12 group at 10 d (p = 0.055) and total protein (TP) tended to increase in the SPC12 group at 42 d (p = 0.080). The contents of total cholesterol (T-CHO) and high-density lipoprotein (HDL) were significantly elevated in the SPC12 group of broilers at 42 d (p < 0.05). In conclusion, dietary inclusion of 12% SPC as a starter diet can be recommended due to the positive effects on broilers.

Community composition of cecal microbiota in commercial yellow broilers with high and low feed efficiencies

The cecal microbiota plays important roles in host food digestion and nutrient absorption, which may in part affect feed efficiency (FE). To investigate the composition and functional differences of cecal microbiota between high (n = 30) and low (n = 29) feed conversion ratio (FCR; metric for FE) groups, we performed 16S rRNA gene sequencing and predicted the metagenome function using Phylogenetic Investigation of Communities by Reconstruction of Unobserved Species in yellow broilers. The results showed that the 2 groups had the same prominent microbes but with differing abundance. Firmicutes, Bacteroidetes, and Actinobacteria were 3 prominent bacterial phyla in the cecal microbial community. Although there were no differences in microbial diversity, compositional differences related to FCR were found via linear discriminant analysis (LDA) effect size; the genus Bacteroides had a significantly higher abundance (LDA >2) in the high FE (HFE) group than in the low FE group. Furthermore, genus Bacteroides had a negative FCR-associated correlation (P < 0.05). Oscillospira was positively correlated with Bacteroides in both groups, whereas Dorea was negatively correlated with Bacteroides in the HFE group. Predictive functional analysis revealed that metabolic pathways such as “starch and sucrose metabolism,” “phenylalanine, tyrosine and tryptophan biosynthesis,” and “carbohydrate metabolism” were significantly enriched in the HFE group. The relatively subtle differences in FE-associated cecal microbiota composition suggest a possible link between cecal microbiota and FE. Moreover, Bacteroides may potentially be used as biomarkers for FE to improve growth performance in yellow broilers.

Effects of Dietary Fiber on Nutrients Utilization and Gut Health of Poultry: A Review of Challenges and Opportunities

Simple Summary

The inclusion of agricultural co-products has been increased to utilize the nutrients in these products available at low cost, but inherently, it adds a high dietary fiber content in the poultry diets. The use of exogenous feed enzymes along with advancements in feed milling, feed formulation, and processing of these non-conventional ingredients to improve their digestibility and utilization have played an emphatic role in boosting their use globally. Despite such developments, the presence of a high level of dietary fibers (DF) acting in an anti-nutritive manner still poses challenges in poultry feeding. Various isolated forms of fiber or feed enzymes to break DF into fermentable substrates are being used extensively to provide potential prebiotics to support beneficial gut microbiota or probiotics to improve the gut health of poultry raised without antibiotic growth promoters (AGP). This review reports and discusses the existing challenges in feeding high-DF feed ingredients to poultry and the opportunities that are available to improve the nutritive value of such non-conventional feed ingredients by adopting various technologies.

Abstract

Many fibrous ingredients incorporated in poultry feed to reduce production costs have low digestibility and cause poor growth in poultry. However, all plant-based fibers are not equal, and thus exert variable physiological effects on the birds, including but not limited to, digestibility, growth performance, and microbial fermentation. Several types of fibers, especially oligosaccharides, when supplemented in poultry diets in isolated form, exhibit prebiotic effects by enhancing beneficial gut microbiota, modulating gut immunity, boosting intestinal mucosal health, and increasing the production of short-chain fatty acids (SCFA) in the gut. Recently, poultry producers are also facing the challenge of limiting the use of antibiotic growth promoters (AGP) in poultry feed. In addition to other alternatives in use, exogenous non-starch polysaccharides digesting enzymes (NSPase) and prebiotics are being used to provide substrates to support the gut microbiome. We also conducted a meta-analysis of different studies conducted in similar experimental conditions to evaluate the variability and conclusiveness in effects of NSPase on growth performance of broilers fed fibrous ingredients. This review presents a holistic approach in discussing the existing challenges of incorporating high-fiber ingredients in poultry feed, as well as strategies to fully utilize the potential of such ingredients in improving feed efficiency and gut health of poultry.

Effect of feeding different levels of lignocellulose on performance, nutrient digestibility, excreta dry matter, and intestinal microbiota in slow growing broilers

Lignocellulose is a constituent of plant cell walls and might be used as a fiber source in poultry nutrition. The current study investigated the impact of increasing dietary levels of lignocellulose on performance, nutrient digestibility, excreta DM, intestinal microbiota, and bacterial metabolites in slow growing broilers. At an age of 10 wk, 60 male broilers of an intercross line (New Hampshire × White Leghorn) were allocated to cages and fed isoenergetic and isonitrogenous diets containing 0.8% (LC1), 5% (LC2), or 10% (LC3) lignocellulose. After 23 D of feeding, broilers were killed and digesta samples of ileum and excreta analyzed for nutrient digestibility and DM. Cecal contents were analyzed for microbial composition and metabolites. Broiler performance was not affected by feeding dietary lignocellulose. LC3 fed broilers showed reduced ileal digestibility of protein compared to chickens fed LC1 (P = 0.003). Moreover, increasing levels of dietary lignocellulose reduced apparent digestibility of organic matter and gross energy (P < 0.001). Feeding of lignocellulose had no impact on the excreta DM of broilers. Increasing levels of dietary lignocellulose lowered cecal counts of Escherichia/Hafnia/Shigella (P = 0.029) and reduced the total concentration of short-chain fatty acids (P < 0.001), lactate (P < 0.05), and ammonia (P = 0.009). The molar ratio of cecal acetic acid was higher in LC3 fed broilers (P < 0.001), while the proportions of cecal propionic acid and n-butyric acid were higher in LC1 and LC2 fed chickens (P < 0.001). Correlation analyses indicated that dietary lignocellulose was negatively related to the total concentration of cecal bacterial metabolites (P < 0.001). In conclusion, the feeding of lignocellulose did not affect growth performance, but impaired nutrient digestibility of slow growing broilers. While minor changes in cecal microbial composition were detected, cecal bacterial metabolite concentrations were significantly reduced with increasing levels of dietary lignocellulose. These findings suggest that lignocellulose is not extensively degraded by bacteria residing in the large intestine of broilers.

Age-related arabinoxylan hydrolysis and fermentation in the gastrointestinal tract of broilers fed wheat-based diets

Endoxylanases are frequently used in cereal-based broiler feeds to improve the nutritional quality of the feed. It is hypothesized that the age of broilers and the age-related development of their intestinal microbiota influence the efficacy of these enzymes. Hence, the objective of this study was to identify possible age-related changes in arabinoxylan (AX) digestion in the different parts of the gastrointestinal (GI) tract of broilers. A feeding trial was performed with 240 1-day-old chicks (Ross 308) receiving a wheat-based feed containing no supplemented endoxylanase. Digesta samples from every section of the GI tract were collected at 5, 10, 15, 21, 28, and 35 d of age and analyzed for AX content, AX digestibility, intestinal viscosity, and microbial endoxylanase and arabinofuranosidase activities. In the first 2 wk, the microbiota were able to solubilize a part of the water-unextractable arabinoxylan (WU-AX), thereby increasing intestinal viscosity and water-extractable arabinoxylan (WE-AX) concentrations in the GI tract. In these young birds, WU-AX and WE-AX with low arabinose to xylose ratios were able to enter the caeca but were not yet extensively fermented by the caecal microbiota as indicated by the high caecal AX concentrations at 5 and 10 d (P < 0.01). Establishment of a more mature microbial community at 3 wk of age resulted in a further increase in both the solubilization of WU-AX and fermentation of WE-AX at the ileum and caecum (P < 0.10). Furthermore, the increase in AX degrading enzyme activities with age denotes the high AX degrading capacity of the caecal microbiota. Finally, a total tract AX digestion of 24% was achieved at slaughter age (day 35). Our results clearly indicate that the capacity of intestinal microbiota to degrade AX in the hindgut increases as the broiler ages. This suggests that the benefits of endoxylanase supplementation of broiler feeds depend on the interaction of the intestinal microbiota and AX present in the GI tract at specific broiler ages.

Cellular elements in the developing caecum of Japanese quail (Coturnix coturnix japonica): morphological, morphometrical, immunohistochemical and electron-microscopic studies

The present study aims to investigate the histological, histochemical and electron microscopic changes of the caecal proximal part of Japanese quail during both pre- and post-hatching periods starting from the 2nd embryonic day (ED) until four weeks post-hatching. On the 2nd and 3rd ED, the primordia of caeca appeared as bilateral swelling on the wall of the hindgut. On the 7th ED, the lamina propria/submucosa contained the primordia of glands. On the 8th ED, rodlet cells could be observed amongst the epithelial cells. On the 9th ED, the caeca began to divide into three parts with more developed layers. With age, the height and number of villi increased. On the 13th ED, immature microfold cells (M-cells) could be identified between the surface epithelium of the villi. The caecal tonsils (CTs) appeared in the form of aggregations of lymphocytes, macrophages, dendritic cells and different types of leukocytes. Telocytes and crypts of Lieberkuhn were observed at this age. On hatching day, the crypts of Lieberkuhn were well-defined and formed of low columnar epithelium, goblet cells, and enteroendocrine cells. Post-hatching, the lumen was filled with villi that exhibited two forms: (1) tongue-shaped villi with tonsils and (2) finger-shaped ones without tonsils. The villi lining epithelium contained simple columnar cells with microvilli that were dispersed with many goblet cells, in addition to the presence of a high number of intra-epithelial lymphocytes and basophils. Moreover, the submucosa was infiltrated by numerous immune cells. CD3 immunomarker was expressed in intraepithelial lymphocytes, while CD20 immunomarker showed focal positivity in CTs. In conclusion, the caecal immune structures of quails at post-hatching were more developed than those in pre-hatching life. The high frequency of immune cells suggests that this proximal part may be a site for immunological surveillance in the quail caecum. The cellular organisation of the caecum and its relation to the immunity was discussed.

Non-cellulosic polysaccharide content in feed ingredients and ileal and total tract non-cellulosic polysaccharide digestibility in 21- and 42-day-old broilers fed diets with and without added composite enzymes

An initial study profiled non-cellulosic polysaccharide (NCP) levels in feed ingredient samples-corn, soybean meal (SBM), whole soybean, and distillers dried grains with solubles (DDGS). A separate NCP digestibility assay was performed in broilers at day 21 (grower phase) and day 42 (finisher phase) fed corn-soy based diets with and without composite enzymes (phytases, multi-carbohydrases, and proteases). Negative control (NC), NC + composite enzymes (NC+E), and positive control (PC) diets were tested. Negative control and NC + E diets were isocaloric, 3,020 kcal/kg ME at grower phase and 3,026 kcal/kg ME at finisher phase. Positive control diet was formulated to meet the Cobb standard nutrient specifications. Diets, pooled digesta, and excreta samples from all treatment diets were collected from 21- and 42-day-old birds and NCP content analyzed as soluble NCP (S-NCP) and insoluble NCP (I-NCP) fractions. Digestibility coefficient (DC) values were determined for all dietary treatments for both the feeding periods. Results from the ingredient analysis showed NCP levels of ∼7 to 10% in corn samples, ∼8 to 11% in SBM samples, ∼11 to 14% (including pectin level) in whole soybean, and ∼12 to 17% in DDGS samples, suggesting variation (P < 0.05) in NCP levels existed within ingredient samples. Digestibility assays showed that enzyme treated (NC + E) diet improved DC values at day 21 from 6 to 10 units and 6 to 9 units for ileal and total tract collection, respectively, for I-NCP fraction (P < 0.05) compared to DC values for NC or PC diets. The ileal DC values at day 42 were not different between treatment diets (∼0.6) but total tract DC values improved 9 to 11 units for broilers fed NC + E diet compared to NC or PC diets. Higher DC values for S-NCP were observed for all treatments for both feeding periods (∼0.7-ileal and ∼0.8-total tract) compared to DC values for I-NCP. Overall, the use of supplemental enzymes in corn-soy-based diets showed improvement in total NCP digestion.

Morphological Characteristics of the Developing Cecum of Japanese Quail (Coturnix coturnix japonica)

The current investigation was carried out to record the final stages of the development of both middle and distal parts of quail ceca, Coturnix coturnix japonica to understand the role of ceca in digestion, immune system, and absorption. The cellular and subcellular structures, including epithelial cell height, microvillus surface area, the proportion of goblet cells, the thickness of muscle layer, and cecum diameter showed great variations during the development. An undeveloped smooth muscularis mucosa was observed for the first time on the ED5. Primordia of glands were observed on the ED7. On the ED15, the middle part exhibited two shapes of mucosal villi: tongue-shaped villi and U-shaped. The plicae and crypts of Lieberkühn were demonstrated on the hatching day. The lymphatic tissues appeared in the wall of both parts of the ceca at the 4 weeks of age. Scanning electron microscopy revealed a great difference in the mucosal surface between different regions. Telocytes were observed in-between the muscle fibers and formed a network during the post-hatching period. Because of fermentation and other bacterial or chemical processes that have been shown to occur in the ceca, this study supports two hypotheses: the cecal development is related to diet and the cecal epithelium act as a site for primary absorption of nutrients or for re-absorption of electrolytes or amino acids derived from the urine.

Effects of dietary supplementation with lysozyme on the structure and function of the cecal microbiota in broiler chickens

Lysozyme is known to eliminate intestinal pathogens in poultry and improve their growth performance. However, whether it can replace antibiotic growth promoters without the associated risk of the emergence of antibiotic-resistant bacterial strains is not known, and the effects of lysozyme supplementation on the composition, biodiversity, and function of the chicken gut microbiota remain unclear. Here, we used the 16S rRNA gene and ITS fragment Illumina sequencing combined with transcriptomic analysis to address this issue. A total of 400 1-d-old Di Gao chicks were allocated randomly to five groups, each consisting of four replicates (20 birds/group). The chicks were fed a starter (1–21 d) and a grower (22–42 d) diet supplemented with 0 (control), 40 (LYS40), 100 (LYS100), or 200 ppm (LYS200) lysozyme, or 400 ppm flavomycin as an antibiotic control for 6 weeks. Lysozyme administration did not contribute significantly (P > 0.05) to the growth of the broiler chickens. No significant (P > 0.05) differences in the diversity and composition of the bacterial and fungal communities in the cecal microbiota of chickens in the different diet groups were found. However, lysozyme supplementation led to a significant (P < 0.05) enrichment of genes involved in the synthesis/degradation of bacterial outer membranes and cell walls, cross-cell substrate transport, and carbohydrate metabolic processes, thus possibly promoting the cecal microbiota carbon and energy metabolism. Bacteroides contributed 31.9% of glycoside hydrolase genes (17,681–24,590), 26.1% of polysaccharide lyase genes (479–675), 20.7% of carbohydrate esterase genes (3,509–4,101), 8.8% of auxiliary activity genes (705–1,000), 16.2% of glycosyltransferase genes (5,301–6,844), and 13.9% of carbohydrate-binding module genes (8838–15,172) identified in the cecal samples. Thus, they were the main players in the breakdown of non-starch polysaccharides in the cecum, although Parabacteroides, Alistipes, Prevotella, Clostridium, Blastocystis, Barnesiella, Blautia, Faecalibacterium, Subdoligranulum, Megamonas, Eubacterium, Ruminococcus, Paenibacillus, Bifidobacterium, Akkermansia, and other bacteria also participated.

Dietary Fiber and Intestinal Health of Monogastric Animals

Animal performance, feed efficiency, and overall health are heavily dependent on gut health. Changes in animal production systems and feed regulations away from the use of antibiotic growth promoters (AGP) have necessitated the identification of strategies to optimize gut health in novel and effective ways. Among alternatives to AGP, the inclusion of dietary fibers (DF) in monogastric diets has been attempted with some success. Alternative feedstuffs and coproducts are typically rich in fiber and can be used in the diets to reduce feed costs and optimize gut health. DF are naturally occurring compounds with a diverse composition and are present in all plant-based feedstuffs. DF stimulate the growth of health-promoting gut bacteria, are fermented in the distal small intestine and large intestine to short-chain fatty acids and have beneficial effects on the immune system. Maternal DF supplementation is one novel strategy suggested to have a beneficial programming effect on the microbial and immune development of their offspring. One mechanism by which DF improves gut health is through maintenance of an anaerobic intestinal environment that subsequently prevents facultative anaerobic pathogens from flourishing. Studies with pigs and poultry have shown that fermentation characteristics and their beneficial effects on gut health vary widely based on type, form, and the physico-chemical properties of the DF. Therefore, it is important to have information on the different types of DF and their role in optimizing gut health. This review will provide information and updates on different types of DF used in monogastric nutrition and its contribution to gut health including microbiology, fermentation characteristics, and innate and adaptive immune responses.

Comparative estimation of inevitable endogenous ileal flow of amino acids in Pekin ducks under varying dietary or physiological conditions and their significance to nutritional requirements for amino acids

In 2 experiments in Pekin ducks the inevitable endogenous ileal flow (IEIF) of AA was estimated at changing intake and source of crude fiber (CF) or soybean oil (SO) level. Also the roles of dry matter intake (DMI) and BW or age as well as the proportion of IEIF in the dietary requirement for AA were studied. In experiment 1 three basal CP (20, 60, or 100 g/kg) diets were formulated containing a low CF (LCF, 30 g/kg) or high (HCF, 80 g/kg) level; achieved with cellulose supplementation. All diets were similar in every other respect including having SO content of 40 g/kg. Four floor pens of eight 85-day-old ducks were randomly allocated to each diet. Similar diets were mixed in experiment 2 but corn cob meal replaced cellulose as the fiber source. A high SO (HSO) series was also formed by increasing the SO level from 40 g/kg in the basal series to 100 g/kg. Thus the LCF series was concurrently classified as low SO (LSO) series to control SO effect. Each of the eventual 9 diets were fed to 5 floor pens of ten 65-day-old ducks. Ileal AA flow was measured after a 5 day feeding period in both experiments. Linear regression was calculated between ileal flow and dietary intake of individual AA. The IEIF interpreted as the y-intercept of each linear function responded neither to elevated ingestion of each CF type nor to SO level. Age and DMI had no effect on IEIF computed in relation to BW, but wide discrepancies resulted when related to DMI. Overall IEIF of AA varied between 14.3 to 129.8 mg/kg BW d-1. These flows were established in model computations to account for 10 to 64% of the recommended intake of limiting AA. In conclusion the ileal inevitable flow is constant within the dietary/age conditions investigated. However it is modulated by feed intake and accounts for a significant portion of total amino acid requirement.

Genome and metagenome analyses reveal adaptive evolution of the host and interaction with the gut microbiota in the goose

The goose is an economically important waterfowl that exhibits unique characteristics and abilities, such as liver fat deposition and fibre digestion. Here, we report de novo whole-genome assemblies for the goose and swan goose and describe the evolutionary relationships among 7 bird species, including domestic and wild geese, which diverged approximately 3.4~6.3 million years ago (Mya). In contrast to chickens as a proximal species, the expanded and rapidly evolving genes found in the goose genome are mainly involved in metabolism, including energy, amino acid and carbohydrate metabolism. Further integrated analysis of the host genome and gut metagenome indicated that the most widely shared functional enrichment of genes occurs for functions such as glycolysis/gluconeogenesis, starch and sucrose metabolism, propanoate metabolism and the citrate cycle. We speculate that the unique physiological abilities of geese benefit from the adaptive evolution of the host genome and symbiotic interactions with gut microbes.

Potential misinterpretation of the nutritional value of dietary fiber: correcting fiber digestibility values for nondietary gut-interfering material

The aim of this review is to identify the origin and implications of a nondietary material present in digesta and feces that interferes with the determination of dietary fiber in gastrointestinal contents. Negative values for ileal and fecal digestibility of dietary fiber are commonly reported in the literature for monogastric animal species, including humans. As negative values are not possible physiologically, this suggests the existence of a nondietary material in the gastrointestinal contents and feces that interferes with the accurate determination of dietary fiber digestibility when conventional methods of fiber determination are applied. To date, little attention has been given to this nondietary interfering material, which appears to be influenced by the type and concentration of fiber in the diet. Interestingly, estimates of dietary fiber digestibility increase substantially when corrected for the nondietary interfering material, which suggests that currently reported values underestimate the digestibility of dietary fiber and may misrepresent where, in the digestive tract, fermentation of fiber occurs. A new perspective of dietary fiber digestion in the gastrointestinal tract is developing, leading to a better understanding of the contribution of dietary fiber to health.

Nondietary Gut Materials Interfere with the Determination of Dietary Fiber Digestibility in Growing Pigs When Using the Prosky Method

BACKGROUND

Reported negative ileal and total tract dietary fiber (DF) digestibility values are physiologically untenable and suggest the presence of nondietary material in the gut contents that interferes with the DF determination.

OBJECTIVE

The objective of this study was to demonstrate the importance of interfering material (IM) when the Prosky method was used to determine DF digestibility.

METHODS

Fourteen pigs (41.6 ± 3.0 kg) were surgically implanted with ileal T-cannulas. A semisynthetic fiber-free diet and 2 semisynthetic diets containing kiwifruit as the sole fiber source [25 or 50 g fiber/kg dry matter (DM)] were prepared. Titanium dioxide was used as an indigestible marker. Pigs were fed the kiwifruit-containing diets (n=7 per diet) for 44 d, followed by the fiber-free diet (n=14) for 7 d. Ileal digesta and feces were collected over 3 d, starting on days 42 and 49. The flow of IM and the soluble, insoluble, and total DF digestibility were determined.

RESULTS

Considerable amounts of IM were present when the Prosky method was applied to ileal digesta (12 g/kg DM intake) and feces (28 g/kg DM intake) collected from pigs fed the fiber-free diet after adaptation to the diet containing 50 g/kg DM of fiber. The pigs adapted to the highest fiber concentration had 0.9- and 0.7-fold greater ileal and fecal IM flows than their counterparts adapted to the lowest concentration. In the ileal digesta, crude mucin was the main IM source in the soluble DF fraction (66%). In the ileal digesta and feces, microbial cells were the main IM source in the insoluble DF fraction. The determined ileal soluble DF and total tract insoluble DF digestibilities increased by 44-54% and 78% respectively after correction for IM (P < 0.001).

CONCLUSIONS

Large amounts of IM are present in ileal digesta and feces of pigs when fiber is determined with the Prosky method, leading to a marked underestimation.

Growth performance, nutrient utilization, and digesta characteristics in broiler chickens fed corn or wheat diets without or with supplemental xylanase

Efficacy of supplemental xylanase on growth performance, nutrient utilization, and digesta characteristics in broiler chickens fed corn- or wheat-based diets was investigated. In experiment 1, 192 male broilers (8 birds/pen; n = 6) were fed 4 diets (corn or wheat without or with 1,250 xylanase units/kg) in 2 phases (starter, d 0-21 and grower, d 22-42). There was no interaction (P > 0.05) between diet and xylanase on performance (d 0-42). Wheat diets resulted (P < 0.01) in better performance than corn diets, whereas xylanase-fed birds had improved (P < 0.01) BW gain (2,457 vs. 2,275 g) and feed per gain (1.677 vs. 1.762) relative to birds not fed xylanase. In experiment 2, TiO2 (0.3%) was added in starter diets used in experiment 1, allocated to 13-d-old broiler chicks (n = 6) housed in cages (6 birds/cage) and fed up to d 21. Excreta samples were obtained from d 17 to 20 and birds were euthanized on d 21 for digesta. Corn diets had a greater concentration (10.7 vs. 9.8%) of insoluble nonstarch polysaccharides (NSP) than wheat diets, which in turn had more than twice the concentration of soluble NSP. There was an interaction (P < 0.03) between diet type and xylanase on jejunal digesta viscosity but not (P > 0.10) on apparent ileal digestibilities of nutrients, cecal volatile fatty acids, and AMEn. In this context, diet type influenced (P < 0.05) cecal volatile fatty acids and retention of nutrients and fiber but did not affect (P = 0.45) AMEn. In contrast, xylanase-fed birds showed higher (P < 0.05) ceca digesta acetic acid, apparent ileal digestibilities of nutrients, and retention of components. As a result, birds fed xylanase had higher AMEn (3,059 vs. 2,995 kcal/kg; P < 0.01) compared with birds not fed xylanase. Although wheat diets had superior growth performance, the AMEn was similar in both diets. Xylanase improved growth performance and AMEn independent of diet type, suggesting hydrolysis of both soluble and insoluble NSP.

Impact of exogenous carbohydrases and phytase on growth performance and nutrient digestibility in broilers

Lu, H., Adedokun, S. A., Preynat, A., Legrand-Defretin, V., Geraert, P. A., Adeola, O. and Ajuwon, K. M. 2013. Impact of exogenous carbohydrases and phytase on growth performance and nutrient digestibility in broilers. Can. J. Anim. Sci. 93: 243–249. The effect of supplementing corn–soybean-based diets with Rovabio®Max AP, an exogenous enzyme mix with carbohydrase (xylanase and β-glucanase) and phytase activities to broiler chickens was evaluated. Male Ross 708 broilers were assigned to four diets: positive control (PC), negative control (NC), deficient in metabolizable energy (ME), crude protein (CP), calcium (Ca) and non-phytate phosphorus (nPP), relative to the PC, by 100 kcal kg−1, 5 g kg−1, 1.1 g kg−1and 1.6 g kg−1, respectively, in the starter and grower diets; and NC+Rovabio®at 0.05 or 0.075 g kg−1diet. Starter diets were fed from day 0 to day 21 and grower diets from day 22 to day 42. Body weight (BW) and body weight gain on days 22 and 42 were increased (P<0.05) by enzyme supplementation. Enzyme addition increased (P<0.05) feed intake from day 22 to day 42 and overall (day 0 to day 42). Gain to feed ratio (G:F) was significantly increased (P<0.05) with enzyme supplementation during both starter and grower phases. Enzyme addition increased (P<0.05) serum phosphorus (P) concentration on day 21. On day 42 enzyme supplementation increased (P<0.05) the apparent ileal digestibility of P, dry matter (DM), energy, and N. Addition of a combination of carbohydrases (xylanase and β-glucanase) and phytase to corn–soybean-based diets deficient in ME, CP, Ca and P resulted in a significant increase in growth performance and utilization of P, DM, energy and N in broiler chickens.

An integrative in vitro approach to analyse digestion of wheat polysaccharides and the effect of enzyme supplementation

The digestion of polysaccharides from the wheat cultivars Caphorn and Isengrain was investigated, and the efficiency of an enzyme preparation was tested using the TNO gastrointestinal model (TIM-1). The apparent digestibility (AD) of carbohydrates was determined based on the measurement of organic matter (OM), total monosaccharides, reducing ends (RE) and end products (EP: glucose, maltose and xylobiose). The AD of the OM from Caphorn and Isengrain measured using caecectomised cockerels did not differ from that measured using TIM-1: 72.0 (SD 2.6) v. 70.6 (SD 0.6) % for Caphorn (P = 0.580) and 73.0 (SD 2.3) v. 71.1 (SD 1.9) % for Isengrain (P = 0.252). After the 6 h TIM-1 digestion, 41.4-58.9 % of the OM, RE and EP were recovered from the jejunal compartment and 18.3-27.1 % from the ileal compartment, while ileal deliveries and digestive residues constituted the remainder. A commercial enzyme cocktail tested at 0.2 μl/g of wheat improved TIM-1 digestibility of Caphorn and Isengrain polysaccharides: 3.9 % (P = 0.0203) and 3.4 % (P = 0.0058) based on the OM; 9.7 % (P < 0.0001) and 3.1 % (P = 0.031) based on the total glucose; 47.2 % (P < 0.0001) and 14.2 % (P = 0.0004) based on the RE, respectively. The enzyme cocktail improved the release of the EP for Caphorn (3.8 %, P = 0.008) but not for Isengrain ( − 0.8 %, P = 0.561). The higher efficiency of the enzyme supplementation on the digestion of Caphorn polysaccharides compared with Isengrain seems to be linked to the higher soluble carbohydrate contents and/or less ramified arabinoxylan of Caphorn.

Chemical composition and biological value of spray dried porcine blood by-products and bone protein hydrolysate for young chickens

The chemical composition of spray dried porcine blood by-products is characterised by wide variation in crude protein contents. In spray dried porcine blood plasma (SDBP) it varied between 670-780 g/kg, in spray dried blood cells (SDBC) between 830-930 g/kg, and in bone protein hydrolysate (BPH) in a range of 740-780 g/kg. Compared with fish meal, these feeds are poor in Met and Lys. Moreover, in BPH deep deficits of Met, Cys, Thr and other amino acids were found. The experiment comprised 7 dietary treatments: SDBP, SDBC, and BPH, each at an inclusion rate of 20 or 40 g/kg diet, plus a control. The addition of 20 or 40 g/kg of the analysed meals into feeds for very young chickens (1-28 d post hatch) significantly decreased the body weight (BW) of birds. Only the treatments with 40 g/kg of SDBP and SDBC showed no significant difference in BW as compared with the control. There were no significant differences between treatments and type of meal for feed intake, haematocrit and haemoglobin concentrations in blood. Addition of bone protein and blood cell meals to feed decreased the IgG concentration in blood and caused shortening of the femur and tibia bones. However, changes in the mineral composition of bones were not significantly affected by the type of meal used. The blood by-products, which are rich in microelements, improved retention of Ca and Cu only. In comparison to control chickens, significantly better accretion of these minerals was found in treatments containing 20 g/kg of SDBP or 40 g/kg of SDBC. Great variability in apparent ileal amino acid digestibility in chickens was determined. In this respect, some significant differences related to the type of meal fed were confirmed for Asp, Pro, Val, Tyr and His. In general, the apparent ileal digestibility of amino acids was about 2-3 percentage units better in chickens fed on diets containing the animal by products than in control birds.

Use of spray-dried porcine blood by-products in diets for young chickens

Spray-dried porcine blood plasma (SDBP) or blood cells (SDBC) at amounts of 20 or 40 g/kg were included to the feed mixtures that were given to young chickens within 1-28 (Exp. 1) or 1-30 (Exp. 2) days post-hatch. In comparison with the group fed mixtures containing plant components, chickens fed mixtures supplemented with 40 g/kg of SDBP significantly (p < 0.01) increased the body weight estimated on 14 day of life (Exp. 1). At the age of 28 or 30 days post-hatch, the body weight was improved significantly (p < 0.01 or 0.05) in both experiments. Significant differences (one-factorial anova) in feed conversion among particular feeding groups were stated in Exp. 1 only; however, calculations using two-factorial anova show insignificant differences depending on the used animal meal. In selected blood parameters (IgG, Ht, Hb), insignificant differences between feeding groups were stated. The use of SDBP in feed mixture significantly increased the Na retention in both experiments, and K accretion in Exp. 1 only. Application of SDBC and 40 g/kg of SDBP significantly or insignificantly improved Fe retention. Insignificant diversification of apparent ileal digestibility of nutrients was stated; the crude fat was significantly better digested in treatments fed mixtures with animal meals but kind of animal meal was without any significant effect. Significant differences in digestibility of amino acids were recorded for Pro, Cys, Val, His, Lys and Arg. In chickens fed mixture with SDBC, higher coefficients of apparent digestibility of Cys, Val and His (Exp. 1) and Cys and His (Exp. 2) than in other feeding groups were obtained. The kind of used blood by-products has not affected the histological structure of intestine wall.

Growth performance, digestibility, and gut development of broiler chickens on diets with inclusion of chicory (Cichorium intybus L.)

A total of 256 broiler chickens (1 d old) were used in a 32-d growth trial to study the effects of chicory (Cichorium intybus L.) forage and root inclusion on growth performance, digestibility, and gut development. The chicory forage originated from 2 harvests (June and September) and was included at 60 and 120 g/kg. The chicory root was included alone at 60 g/kg or together with chicory forage, from both harvests, in equal amounts (60 g/kg). The cereal-based control diet and 7 experimental diets were fed to each of 4 pens of chickens (8 chickens/pen). A higher BW gain and lower feed conversion ratio were found at 13 d of age in chickens fed the 60 g/kg chicory forage diet (P ≤ 0.05), whereas performance did not differ between the control and 60 g/kg chicory root diets. In contrast, a lower performance and digestibility of DM, organic matter, and AME as well as a thinner cecal mucosa layer were found for the 120 g/kg chicory forage diet (P ≤ 0.05). No diet effects on organ parameters or on pH of cecum digesta were detected. The soluble nonstarch polysaccharides fractions of chicory forage did not have any major negative effects on performance and gut development, and chicory forage from the September harvest was seen to have a higher nutritional value than that from the June harvest. Thus, results from the current study suggest that chicory forage is a potentially useful fiber-rich feed ingredient with high palatability for broiler chickens.

Application of soybean meal, soy protein concentrate and isolate differing in α-galactosides content to low- and high-fibre diets in growing turkeys

The aim of this experiment was to investigate the physiological and growth response of young turkeys (up to 8 weeks of age) to dietary replacement of soybean meal (SBM) by soy protein concentrate (PC) or protein isolate (PI). This replacement resulted in a differentiated dietary concentration of α-galactosides of over 2.5% in the SBM diet, approximately 2% with a mixture SBM and PC, 1% with a PC diet and 0.1% with a PI diet. Each treatment was applied in two ways: with lower (3.5%) or higher (5.3%) dietary crude fibre content, made by supplementation with soybean hulls. The highest and lowest body weight of turkeys was recorded both after the first and second 4-week half of the study in the PC and PI-type diets respectively. A gradual withdrawal of α-galactosides from a diet was accompanied by a decline in ileal tissue mass, ileal viscosity and activity of endogenous maltase (the latter was found to be significant at 4 weeks of age). At the same time, two-way anova revealed that an elevated level of crude fibre (HF treatment) caused an increase in ileal tissue mass (p < 0.05 after 4 weeks of feeding) as well as a decrease in activity level of intestinal sucrase and maltase. The presence of raffinose family oligosaccharides in a diet, in contrast to dietary crude fibre level, significantly affected the caecal metabolism. The rate of bacterial production of short-chain fatty acids in the caeca was distinctly diminished by dietary withdrawal of α-galactosides. In conclusion, the soy protein concentrate, in contrast to the protein isolate preparation, exerted positive effects on the turkeys' growth and gastrointestinal tract physiology and should be considered as an effective SBM substitute.