Lignocellulose as an insoluble fiber source in poultry nutrition: a review

Comprehensive analysis of gene expressions in ileal mucosa of chickens fed paddy rice and their IgA response to oral vaccination

Paddy rice ingestion increases intestinal mucin secretion and production by enhancing MUC2 gene expression and epithelial turnover. In this study, we performed a comprehensive analysis of intestinal gene expression in chickens fed paddy rice and investigated whether the intestinal IgA response was modified by paddy rice ingestion. Furthermore, we investigated the possible involvement of gut fermentation. Layer male chicks were divided into two groups according to diet i.e., corn or paddy rice at 650 g/kg diet, which were given for 14 consecutive days at 7 d of age. The ileal gene expression levels in both groups were compared using DNA microarray analysis. A total of 120 genes were upregulated >1.5-fold in the paddy rice group, whereas 159 genes were downregulated <1.5-fold. Remarkably, the gene expression levels of immunoglobulin heavy chain α (IGHA), immunoglobulin J chain (IGJ), and immunoglobulin light chain λ chain region (IGLL1), which constitute immunoglobulin A, decreased 3-10 times in the paddy rice group. Infectious bursal disease virus (IBDV) vaccine were orally administered to chickens fed corn or paddy rice to examine the intestinal immune response. Paddy rice ingestion diminished both the total IgA concentration and IBDV-specific IgA in the bile. Cecal total short-chain fatty acid and butyric acid concentrations decreased by 30 % in the paddy rice group compared to those in the corn group. In conclusion, feeding paddy rice to chickens decreased intestinal IgA production, which was partly attributable to the low fermentability of paddy rice in the intestinal tract.

Exploring the Potential Effects of Soybean By-Product (Hulls) and Enzyme (Beta-Mannanase) on Laying Hens During Peak Production

This study determined the interaction between soybean hulls (SHs) and enzymes (β-mannanase) to improve the sustainability and efficacy of feeding programs for laying hens during peak production while ensuring the best health and efficiency. In a completely randomized design (CRD), 200 golden-brown hens were fed for four weeks (33 to 36 weeks) and randomly distributed into four groups, each containing four replicates of ten birds, with one group receiving a control diet (P0) and the others receiving diets that contained four combinations of SHs and enzymes (ENZs). e.g., 3% SHs and 0.02 g/kg ENZs (P1), 3% SHs and 0.03 g/kg ENZs (P2), 9% SHs and 0.02 g/kg ENZs (P3), and 9% SHs and 0.03 g/kg ENZs (P4). Although most egg quality measures remained similar, the P2 group showed enhanced (p = 0.630) egg weight, albumen weight, and height. Moreover, the P2 group improved gut (p < 0.05) shape by increasing villus width, height, crypt depth, and surface area throughout intestinal sections, while the P4 group markedly improved total cholesterol and LDL (p = 0.022) levels. The P1, P2, and P4 groups exhibited a significant enhancement in dry matter (p = 0.022) and crude fiber (p = 0.046) digestibility, while the P2 group demonstrated superior crude protein digestibility (p = 0.032), and the P1 and P2 groups showed increased crude fat digestibility compared to the other groups. In conclusion, adding 3% of SHs and 30 mg/kg of ENZs (β-mannanase) to the feed may help laying hens, enhance gut health and some egg quality indices, and decrease blood cholesterol and LDL levels without compromising nutrient digestibility.

A Spatiotemporal Transcriptome Reveals Stalk Development in Pearl Millet

Pearl millet is a major cereal crop that feeds more than 90 million people worldwide in arid and semi-arid regions. The stalk phenotypes of Poaceous grasses are critical for their productivity and stress tolerance; however, the molecular mechanisms governing stalk development in pearl millet remain to be deciphered. In this study, we spatiotemporally measured 19 transcriptomes for stalk internodes of four different early developmental stages. Data analysis of the transcriptomes defined four developmental zones on the stalks and identified 12 specific gene sets with specific expression patterns across the zones. Using weighted gene co-expression network analysis (WGCNA), we found that two co-expression modules together with candidate genes were involved in stalk elongation and the thickening of pearl millet. Among the elongation-related candidate genes, we established by SELEX that a MYB-family transcription factor PMF7G02448 can bind to the promoters of three cell wall synthases genes (CesAs). In summary, these findings provide insights into stalk development and offer potential targets for future genetic improvement in pearl millet.

Effects of β-Mannanase Supplementation and Soyhull Inclusion on Production Performance, Economics, Egg Quality, Blood Biochemicals, Nutrient Digestibility, and Intestinal Morphology in Golden Brown Hens (RIR × Fayoumi) during Late Peak Production

This study investigated the effects of the β-mannanase enzyme and soyhulls on production performance, economics, egg quality, hematology and serum biochemistry, nutrient digestibility, gut morphology, digesta viscosity, and excreta consistency in laying hens during the late peak production phase (37 to 40 weeks of age). Golden brown hens (RIR × Fayoumi; n = 200) were fed a control diet (no soyhulls or enzymes) and diets containing four combinations, i.e., 3% soyhulls with 20 mg/kg β-mannanase (D1), 3% soyhulls with 30 mg/kg β-mannanase (D2), 9% soyhulls with 20 mg/kg β-mannanase (D3), and 9% soyhulls with 30 mg/kg β-mannanase (D4), for four weeks in four replicates of 10 birds each. Overall, a significantly higher (p < 0.05) feed intake, weight gain, feed conversion ratio, and water intake were calculated in the D2 group as compared to the control and remaining combinations of soyhulls and β-mannanase. No mortality was recorded during the entire experiment. Economically, the D1 and D2 groups showed the best results as compared to the D3 and D4 groups. Egg quality parameters like egg weight, shell weight and shell thickness, yolk weight, albumen weight and height, and the Haugh unit remained unchanged (p > 0.05). Similarly, the D2 group showed significantly lower total cholesterol, LDL, and VLDL levels and enhanced gut morphology with greater villus width, height, crypt depth, and surface area across intestinal segments. Crude protein (CP), crude fiber (CF), crude fat, and ash digestibility were higher (p < 0.05) in the D1 and D2 groups compared to the control. Digesta viscosity, excreta consistency, and other egg quality parameters remained unaffected. In conclusion, the dietary inclusion of a combination of 3% soyhulls and 30 mg/kg β-mannanase may have potential benefits for laying hens by improving some production performance and egg quality indicators and economics, lowering blood cholesterol, LDL, and VLDL levels, enhancing nutrient digestibility, and improving gut morphology without affecting egg quality.

Effects of carriers for oils in compound feeds on growth performance, nutrient digestibility, and gut microbiota in broiler chickens

Carrier materials for oils in compound feeds may be used in animal nutrition to supply liquid feed additives. However, implications of such carriers for the digestibility of the contained oil are unknown. This study investigated the potential of oil carriers in compound feed and their effect on performance, metabolizable energy, fatty acid (FA) retention, amino acid (AA) digestibility, and gut microbiota in broiler chickens. Six experimental diets were formulated following a 2 × 3 factorial arrangement with 20 g/kg or 40 g/kg of rapeseed oil supplied with no carrier or bound in a silica-based (SC) or lignocellulose-based (LC) carrier in a 1:1 mass ratio. The diets were assigned to 48 metabolism units with 15 animals each based on a randomized complete block design and fed from d 18 to 28 of the trial. Total excreta were collected from d 24 to 27 and used to determine total tract retention (TTR) of FA and MEn. On d 28, AA digestibility both by the distal half of the jejunum and the distal half of the ileum was determined, and microbiota of ileal and cecal digesta was analyzed using 16S ribosomal RNA sequencing. There were significant interactions for ADG, ADFI, the gain:feed ratio (G:F), MEn, and the TTR of crude fat and most fatty acids (P ≤ 0.046) except for C18, C18:2, and C22:0. Addition of SC decreased ADG, ADFI, and G:F (P < 0.001), while LC at 40 g/kg oil inclusion increased G:F and MEn (P < 0.001) for both inclusion levels. The TTR of crude fat and the FA C18:1, C18:2, C18:3, and C22:0 was increased by the addition of SC (P ≤ 0.016), while LC increased the TTR of the FA C18:1 and C18:2 as well as the TTR of C18:3 at 20 g/kg oil inclusion (P ≤ 0.016). Adding SC and LC increased the digestibility of 7 and 2 AA by the distal half of the jejunum, respectively, and the digestibility of 8 and 13 AA by the distal half of the ileum, respectively (P ≤ 0.039). The β-diversity and abundance of some taxa were altered by addition of LC and SC in the ceca while no treatment effect on the ileal microbiota was found. The results give no indication of an incomplete release of the oil from the carriers because the TTR of most FA was increased upon addition of SC and LC. LC may be used to supply liposoluble feed additives without drawbacks for nutrient digestibility and growth while SC requires further examination.

Performance and nutrient digestibility of growing pigs fed highly or low fermentable coarse or finely ground fibre-rich feedstuffs

Dietary fibre is mainly classified according to its chemical characteristics but structure and particle size of fibre-rich feedstuff can also be decisive for digestion and performance. So far, only few studies investigated this in pigs. This experiment aimed to compare coarse and finely ground dried hemp plants and apple pomace regarding performance and ileal and total tract nutrient digestibility of growing pigs. Coarse or finely ground apple pomace or dried hemp plants were added to the diet of 56 nine weeks old growing pigs (DanBred x Duroc), housed in flat decks with each 2 animals. The growing pigs received the experimental diets for three weeks while performance was recorded. Eight pigs per group were sacrificed and digesta and organ tissue sampled. The stomach health was evaluated by visually scoring of the mucosa integrity. Apparent ileal (AID) and total tract digestibility (ATTD) were calculated using titanium dioxide as marker. Statistical analyses were performed using two-way ANOVA (p < 0.05). The highest feed intake (fibre particle size, p = 0.018) and bodyweight gain (fibre particle size, p = 0.018; fibre source x particle size interaction, p = 0.040), was observed in animals fed finely ground apple pomace, while the feed conversion ratio was 8-12% lower in pigs fed finely ground fibre sources (p = 0.012). No differences in stomach mucosa integrity were detected between the groups. The relative pancreas (p = 0.045), stomach (p < 0.001), and jejunum (p = 0.010) weights were higher in animals fed diets containing apple pomace. In contrast, the relative liver, caecum and colon weights were not affected by fibre source or particle size. The AID of protein and amino acids was not affected, while ATTD was increased by fibre source (hemp vs. apple pomace) reducing faecal nitrogen excretion. The AID of calcium was increased when diets contained apple pomace (p < 0.001), while zinc AID and ATTD were enhanced when diets contained dried hemp (p = 0.016; p = 0.016, respectively). Our results suggest that the structure as well as the chemical characteristics should be considered in a future fibre evaluation system in pigs.

Catalyzed Hydrothermal Pretreatment of Oat Husks for Integrated Production of Furfural and Lignocellulosic Residue

This study presents a novel approach for biorefining oat husks into furfural, leveraging a unique pilot-scale setup. Unlike conventional furfural manufacturing processes, which often result in substantial cellulose degradation and environmental concerns associated with sulfuric acid usage, our method utilizes phosphoric acid as a catalyst to achieve high furfural yield while minimizing cellulose destruction. Drawing on our research conducted in a distinctive pilot-scale environment, we successfully developed and implemented a tailored biorefining process for oat husks. Through meticulous experimentation, we attained a remarkable furfural yield of 11.84% from oven-dried mass, accompanied by a 2.64% yield of acetic acid. Importantly, our approach significantly mitigated cellulose degradation, preserving 88.31% of the cellulose content in oat husks. Existing catalytic (H2SO4) furfural manufacturing processes often lead to substantial cellulose degradation (40-50%) in lignocellulosic leftover during the pretreatment stage. As a result of the research, it was also possible to reduce the destruction of cellulose in the lignocellulose leftover to 11.69% of the output (initial) cellulose of oat husks. This research underscores the feasibility and sustainability of utilizing oat husks as a valuable feedstock for furfural production, highlighting the potential of phosphoric acid as a catalyst in biorefining processes. By showcasing our unique pilot-scale methodology, this study contributes to advancing the field of environmentally friendly biorefining technologies.

Effects of the Addition of Crude Fibre Concentrate on Performance, Welfare and Selected Caecal Bacteria of Broilers

The study evaluated the effects of crude fibre concentrate supplementation on final body weight, mortality, feed conversion ratio, European Production Efficiency Factor, European Broiler Index, welfare parameters, colony-forming units of selected caecal bacteria (Enterobacteriaceae and lactic acid bacteria) and pH of broiler faeces and litter. The study comprised 990 Ross 308 male chicks divided into three groups, a control and two experimental groups, which were given crude fibre concentrate as a feed supplement. On the thirty-fifth day of rearing, the birds' welfare scores were evaluated, and 2 g of cecum was collected post-mortem from six chickens in each group. Subsequently, a series of ten-fold dilutions of the material was prepared, followed by cultures and measurement of pH in the faeces and litter. The inclusion of crude fibre concentrate resulted in a beneficial impact on the ultimate body mass (p ≤ 0.001), welfare standard (p ≤ 0.001), and quantity of colony-forming units of lactic acid bacteria (p ≤ 0.05) within the cecum. Furthermore, it had a positive influence on lowering the pH levels of both faeces and litter (p ≤ 0.05).

Effect of Particle Size of Wheat and Barley Grain on the Digestibility and Fermentation of Carbohydrates in the Small and Large Intestines of Growing Pigs

The objective of this investigation was to study the effects of different cereal types, barley and wheat, with different particle sizes (PS) on the recovery of ileal digesta and fecal excretion, digestion of nutrients and fiber components, mean transit time (MTT), and short-chain fatty acid content and composition in growing pigs studied in two experiments. Five barrows with ileal cannulas (initial BW 35.9 ± 1.5 kg) in Experiment 1 and thirty-two castrated pigs (30.8 ± 1.3 kg) in Experiment 2 were fed four different diets: barley fine, barley coarse, wheat fine and wheat coarse diets. The cereal type and PS did not influence the relative weight of the small and large intestines and pH of digesta, whereas MTT in the large intestine of pigs fed the coarse barley diet was lower compared to pigs fed other diets (p < 0.05). Pigs fed the coarse barley diet had lower apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of nutrients and fiber (p < 0.05), whereas pigs fed the fine barley diet had similar AID and ATTD to pigs fed wheat fine and coarse diets (p < 0.05). In conclusion, the barley diet was more influenced by PS in comparison to wheat, thereby inducing lower AID and ATTD of nutrient.

Longitudinal Study of the Effects of Flammulina velutipes Stipe Wastes on the Cecal Microbiota of Laying Hens

Because antibiotics have been phased out of use in poultry feed, measures to improve intestinal health have been sought. Dietary fiber may be beneficial to intestinal health by modulating gut microbial composition, but the exact changes it induces remain unclear. In this study, we evaluated the effect of Flammulina velutipes stipe wastes (FVW) on the cecal microbiotas of laying chickens at ages spanning birth to 490 days. Using clonal sequencing and 16S rRNA high-throughput sequencing, we showed that FVW improved the microbial diversity when they under fluctuated. The evolvement of the microbiota enhanced the physiological development of laying hens. Supplementation of FVW enriched the relative abundance of Sutterella, Ruminiclostridium, Synergistes, Anaerostipes, and Rikenellaceae, strengthened the positive connection between Firmicutes and Bacteroidetes, and increased the concentration of short-chain fatty acids (SCFAs) in early life. FVW maintains gut microbiota homeostasis by regulating Th1, Th2, and Th17 balance and secretory IgA (S-IgA) level. In conclusion, we showed that FVW induces microbial changes that are potentially beneficial for intestinal immunity. IMPORTANCE Dietary fiber is popularly used in poultry farming to improve host health and metabolism. Microbial composition is known to be influenced by dietary fiber use, although the exact FVW-induced changes remain unclear. This study provided a first comparison of the effects of FVW and the most commonly used antibiotic growth promoter (flavomycin) on the cecal microbiotas of laying hens from birth to 490 days of age. We found that supplementation with FVW altered cecal microbial composition, thereby affecting the correlation network between members of the microbiota, and subsequently affecting the intestinal immune homeostasis.

Poultry nutrition

Nutrition is the most important environmental factor affecting development, health status, growth performance and profitability of poultry production. Feeds for poultry constitute up to 70–75% of total production costs. Poultry nutrition differs considerably from that of other livestock, which is determined by the specific anatomy of the gastrointestinal tract. Protein, energy, fat, fiber, minerals, vitamins, and water are of basic importance for poultry nutrition and their content in feeds must cover the requirement that differ depending on the bird’s age and species. In general, feed protein must be of good value including the content of essential amino acids. Among them lysine, methionine, cysteine, threonine and tryptophan are the limiting ones. The main ingredient of poultry feeds are cereal grains, i.e. wheat and maize, which predominantly constitute an energy source because their protein content is insufficient for birds. Because of that cereals cannot be the only feed for poultry and must be combined with protein sources such as soybean or rapeseed meal, legume seeds or protein concentrates. Despite birds’ requirement for nutrients and chemical composition of feeds are well known, nutrition must face many problems. One of the most important issues is to find alternatives to antibiotic growth promoters.

Influence of Insoluble Dietary Fibre on Expression of Pro-Inflammatory Marker Genes in Caecum, Ileal Morphology, Performance, and Foot Pad Dermatitis in Broiler

In a low-fibre diet destined for broilers, the effects of two lignocellulose products and soybean hulls were evaluated regarding their effect on ileal morphometric parameters, caecal gene expression, foot pad dermatitis, and performance. A total of 5040-day-old broilers (Ross 308) were allotted to four treatments and fattened for 36 days applying a three-phase feeding program. The control diet consisted of corn, wheat, and soybean meal. Experimental diets were supplemented with 0.8% lignocellulose product 1, 0.8% lignocellulose product 2, or 1.6% soybean hulls. Tissue samples for caecal expression of inflammation-related genes and ileal morphometries were collected on day 21. Gizzard pH and weights were recorded, and foot pad scores were evaluated at day of slaughter (day 36). In starter (day 1−10) and finisher phase (day 28−36), no effect on the performance was observed. In grower phase (day 11−27), fibre-supplemented diets showed significantly heavier body weights and daily weight gains (p < 0.05). Daily feed intake, feed conversion ratio, and gene expression analysis were unaffected by dietary fibre supplementation. Positive effects regarding ileal morphometrics (higher villi) and foot pad health occurred in fibre-supplemented diets. In conclusion, fibre supplementation improved performance in grower phase and showed beneficial effects regarding ileal morphology and foot pad dermatitis.

Co-interventions with Clostridium butyricum and soluble dietary fiber targeting the gut microbiota improve MAFLD via the Acly/Nrf2/NF-κB signaling pathway

Purpose: The pathogenesis of metabolic associated fatty liver disease (MAFLD) is complex. Lipid metabolic disorder, chronic inflammation, and oxidative stress are the core events for MAFLD. Dietary intervention is an important treatment strategy for preventing the onset and progression of MAFLD. Clostridium butyricum (CB) and soluble dietary fiber (SDF) are often considered beneficial for health. We explored how two microbiota-targeted interventions (SDF and CB) influence the hepatic immune system, oxidative stress, and lipid metabolism in MAFLD mice. Methods: To explore the role of SDF and CB in MAFLD, we generated MAFLD mouse models by feeding C57BL/6 mice with a high-fat diet (HFD). After 8 weeks of intervention, we measured immune cell function, lipid metabolism, and oxidative stress levels in the livers of mice. Results: Single intervention with SDF or CB was not effective in improving MAFLD; however, co-interventions with SDF and CB increased microbiota diversity and decreased inflammation, oxidative stress, and lipid synthesis. Moreover, we determined that co-intervention with SDF and CB mediated fatty acid oxidation by activating the Acly/Nrf2/NF-κB signaling pathway. Most importantly, co-intervention exerted anti-inflammatory effects by inhibiting the differentiation of macrophages into pro-inflammatory M1 macrophages. Conclusion: This study show that co-intervention with SDF and CB can improve MAFLD, and co-intervention with  SDF and CB are suggested to be potential gut microbiota modulators and therapeutic substances for MAFLD.