Effects of dietary oligosaccharide supplementation on growth performance, concentrations of the major odor-causing compounds in excreta, and the cecal microflora of broilers

Effect of dietary supplementation of two fiber sources differing on fermentability and hydration capacity on performance, nutrient digestibility and cecal fermentation in broilers from 1 to 42 d of age

A total of 378 Cobb-500 male broilers were used to evaluate the effects of 2 fiber sources, differing in hydration capacity and fermentability, on gastrointestinal tract development, apparent ileal digestibility and performance from 1 to 42d of age. There were 9 replicates per each of the 3 dietary treatments, all in mash form: a wheat-soybean control (CON) diet, CON diet diluted with 1.5% of wood lignocellulose (LC diet) as a non-fermentable insoluble fiber with high hydration capacity; and CON diluted with 1.5% of a mixture of fibers (ISFC diet) containing both lignified insoluble fiber and a prebiotic soluble fiber fraction from fructooligosaccharides. Additionally, the fermentability of both fiber sources (LC and ISFC) was determined by in vitro using cecal inoculum from broilers fed the experimental diets. Both LC and ISFC treatments impaired by 4% feed conversion ratio only during the first 7d (P = 0.003) compared with CON group. In the grower period (21-42d), the ISFC group showed the best growth (P = 0.039), and at 42d tended to show the highest body weight (P = 0.095). This agrees well with the highest ileal dry matter (P = 0.033) and organic matter (P = 0.043) digestibility observed in ISFC group and the similar trend observed for ileal protein digestibility (P = 0.099) at 42d. Also, at 42 d, absolute and relative (% body weight) digestive tract weights (P ≤ 0.041) and empty gizzard weights (P ≤ 0.034) were greater for LC and ISFC groups compared to CON. The cecal molar proportion of valeratewas greatest in ISFC group (P = 0.039). In vitro gas production was higher for ISFC than for LC substrate when using either a diet-adapted or non-adapted cecal inoculum (P < 0.05). These results show the interest in combining IF with prebiotic highly fermentable fiber, such as fructooligosaccharides, in broilers to improve nutrient digestibility and finishing performance.

Nutritional and physiological responses to dietary phosphorus levels and phytase in pullets and laying hens

The objective of this study was to determine the effects of dietary available phosphorus (P) levels and dietary phytase added into the very low-P diet on the performance, mineral balance, odor emission, and stress responses in growing pullets and laying hens during 13 to 32 wk of age. One hundred sixty-eight pullets (Hy-Line Brown) were randomly assigned into 1 of 4 dietary treatments with 7 replicates of 6 birds each. Experimental diets were formulated to contain 3 graded P levels at 0.25, 0.35, and 0.45% during 13 to 15 wk (phase 1), 0.25, 0.35, and 0.45% during 16 to 18 wk (phase 2), and 0.20, 0.30, and 0.40% during 19 to 32 wk (phase 3). In addition, dietary phytase (500 FTU/kg matrix values) was added into the very low-P diets (0.20% during 13-15 wk, 0.25% during 16-18 wk, and 0.20% during 19-32 wk) to meet the nutritional adequacy with standard P diets. In all phases, decreasing dietary P levels did not affect (P > 0.05) growth, laying performance, and egg qualities. Decreasing dietary P levels linearly increased the relative duodenal and oviduct weights (P < 0.05), and quadratically increased the relative ovary weight in pullets (P = 0.016). Dietary phytase lowered (P = 0.021) the relative duodenal weight compared with the very low-P diet. Tibia breaking strength and tibia Mg contents in pullets were linearly lowered (P < 0.05) as dietary P levels decreased. Dietary phytase tended to increase (P = 0.091) tibia breaking strength and significantly increased (P = 0.025) tibia Mg content compared with the very low-P diet. Dietary P levels and dietary phytase affected (P < 0.05) ileal crypt depth and ileal villus height: crypt depth ratio in pullets. Decreasing dietary P levels linearly decreased (P < 0.01) crude fat digestibility and P excretion in both pullets and laying hens. Dietary phytase reversed (P < 0.05) the very low-P diet-mediated decrease of crude fat digestibility in pullets and laying hens. Dietary P levels and dietary phytase affected (P < 0.05) odor emission including ammonia in pullets and total volatile fatty acids in laying hens. Finally, lowering dietary P levels increased (P < 0.01) yolk corticosterone concentrations and the increased corticosterone concentration by the very low-P diet was reversed by dietary phytase. Collectively, our study shows that decreasing dietary P levels induced nutritional and physiological responses in pullets and laying hens and these P-mediated negative effects were mitigated by dietary phytase.

Prebiotic effects of Talinum triangulare and Mangifera indica on slow growing broiler chickens (SASSO)

1

The study aim was to evaluate the prebiotic effects of Talinum triangulare and Mangifera indica used on slow growing broiler chickens.

2

Three hundred and sixty (360) slow-growing chicks of four weeks of age and similar weight were selected and divided into four (04) treatments (Positive Control, Negative Control, 2 % T. triangulare and 2 % M. indica) of 6 replicates with, fifteen (15) chicks per replicate, which made ninety (90) chicks per treatment.

3

At 12 week age, blood sample and cecal content were taken from 6 chickens per treatment to determine heamatological profile and fermentation parameters (Short Chain Fatty Acid). The data obtained were submitted to one-way analysis of variance (ANOVA) using the software R version 3.6.2 (R Core Team, 2019).

4

Results showed that growth performance, haematological parameters, acetic, butyric, valeric and caproic acids were similar between broilers fed with the leave powders and the positive control treatment. However, broilers fed with Talinum triangulare and Mangifera indica powders showed a lower mortality rate, compared to the negative and positive control treatments. Moreover, broilers fed with the leave powders showed significantly higher (p < 0.05) formic acid concentration than the other treatments.

5

Talinum triangulare and Mangifera indica leaves could have prebiotic properties because they stimulated the production of short-chain fatty acids that keep animals healthy.

A review on the effect of soy bioactive components on growth and health outcomes in pigs and broiler chickens

While soy products have long been included in animal diets for their macronutrient fractions, more recent work has focused on the immunomodulatory potential of bioactive components of this feedstuff. This comprehensive review aims to identify the current state of knowledge on minor soy fractions and their impact on the health and growth of pigs and broiler chickens to better direct future research. A total of 7,683 publications were screened, yet only 151 were included in the review after exclusion criteria were applied, with the majority (n = 87) of these studies conducted in pigs. In both species, antinutritional factors and carbohydrates, like stachyose and raffinose, were the most frequently studied categories of bioactive components. For both categories, most publications were evaluating ways to decrease the prevalence of the examined components in soy products, especially when fed at earlier ages. Overall, most studies evaluated the effect of the bioactive component on performance-related outcomes (n = 137), followed by microbial analysis (n = 38) and intestinal structure and integrity measures (n = 37). As they were analyzed in the majority of publications, antinutritional factors were also the most frequently investigated category in relation to each specific outcome. This trend did not hold true for microbiota- or antioxidant-associated outcomes, which were most often studied with carbohydrates or polyphenols, respectively. Changes to the host microbiota have the potential to modulate the immune system, feed intake, and social behaviors through the microbiota-gut-brain axis, though few publications measured behavior and brain characteristics as an outcome. Other identified gaps in research included the study of soy saponins, as most research focused on saponins derived from other plants, the study of phytosterols outside of their role in cardiovascular or reproductive outcomes, and the general examination of bioactive peptides. Overall, given soy's popularity as a current constituent of animal feed, additional research into these bioactive components may serve to define the value of soy products through their potential ability to support the productivity, health, and well-being of animals.

Lactobacillus-driven feed fermentation regulates microbiota metabolism and reduces odor emission from the feces of pigs

IMPORTANCE

Our present study showed that dietary supplementation with feed fermented by Lactobacillus could promote the growth performance of pigs, regulate the microbiota, and inhibit the growth of harmful bacteria. It could prevent the accumulation of toxic substances and reduce odor emission from pig feces, thereby reducing environmental pollution. In addition, one key triumph of the present study was the isolation of Weissella cibaria ZWC030, and the strain could inhibit the production of skatole in vitro in our present results.

Effects of nonantibiotic growth promoter combinations on growth performance, nutrient utilization, digestive enzymes, intestinal morphology, and cecal microflora of broilers

Given the ban on antibiotic growth promoters, the effects of nonantibiotic alternative growth promoter combinations (NAGPCs) on the growth performance, nutrient utilization, digestive enzyme activity, intestinal morphology, and cecal microflora of broilers were evaluated. All birds were fed pellets of two basal diets-starter (0-21 d) and grower (22-42 d)-with either enramycin (ENR) or NAGPC supplemented. 1) control + ENR; 2) control diet (CON, basal diet); 3) control + mannose oligosaccharide (MOS) + mannanase (MAN) + sodium butyrate (SB) (MMS); 4) control + MOS + MAN + Bacillus subtilis (BS) (MMB); 5) control + MOS + fruit oligosaccharide (FOS) + SB (MFS); 6) control + FOS + BS (MFB); 7) control + MOS + FOS + MAN (MFM); 8) control + MOS + BS + phytase (PT) (MBP). ENR, MOS, FOS, SB, MAN, PT, and BS were added at 100, 2,000, 9,000, 1,500, 300, 37, and 500 mg/kg, respectively. The experiment used a completely random block design with six replicates per group: 2400 Ross 308 broilers in the starter phase and 768 in the grower phase. All NAGPCs significantly improved body weight gain (P < 0.01), utilization of dry matter, organic matter, and crude protein (P < 0.05), villus height and villus height/crypt depth in the jejunum and ileum (P < 0.01), and decreased the feed conversion ratio (P < 0.01) at d 21 and 42. MMS, MMB, MFB, and MFM duodenum trypsin, lipase, and amylase activities increased significantly (P < 0.05) at d 21 and 42. On d 21 and 42, MMS, MMB, and MBP increased the abundance of Firmicutes and Bacteroides whereas MMB, MFB, and MBP decreased the abundance of Proteobacteria, compared to ENR and CON. Overall, the NAGPCs were found to have some beneficial effects and may be used as effective antibiotic replacements in broilers.

Interaction between dietary digestible tryptophan and soy oligosaccharides in broiler chickens: effects on caecal skatole level and microflora

OBJECTIVE

This study was conducted to evaluate the interactive effects of dietary digestible tryptophan (dTry) and soy oligosaccharides (SO) on growth performance, caecal skatole level, and microflora of broiler chickens aged from 14 to 42 days.

METHODS

Three hundred and sixty broiler chicks were allocated equally to 36 cages at 14-dayof- age according to body weight and gender. Using a 3×2 factorial arrangement, 3 dietary dTry levels (0.18%, 0.23%, and 0.28%) supplemented with 0 or 3.5 g/kg of SO were used to create 6 diets (treatments). Each diet was fed to six replicates of 10 birds (60 birds/treatment), growth performance was measured. Caecal content samples were collected at 42 days of age.

RESULTS

Results showed that significantly different dTry level×SO interactions were found for average daily gain (ADG), caecal levels of indole, propionic acid, and butyric acid, and microbial Shannon index (p<0.05). Birds fed diet containing 0.23% dTry level with SO supplementation had higher ADG and lower feed/gain ratio than those fed the other diets (p<0.05). Broilers fed diets containing 0.28% dTry increased their caecal levels of indole and skatole compared with those containing 0.18% or 0.23% dTry (p<0.01), regardless of SO addition. SO supplementation to diets decreased the caecal skatole level by 16.17% (p<0.05), and increased the relative frequency of Clostridium IV (p<0.05), regardless of dietary dTry level.

CONCLUSION

These results indicated that diets containing 0.23% dTry with SO supplementation positively promoted ADG, and decreased caecal skatole levels of broiler chickens. The dietary dTry level, SO affected the caecal skatole level, however, there was no interaction between them.

Effects of alginates on the growth, haematological, immunity, antioxidant and pro-inflammatory responses of rabbits under high temperature

Heat stress (HS) is one of the most severe hurdles impacting rabbit growth, immunity, homeostasis, and productivity. Alginate oligosaccharides (AOS) have considerable beneficial effects due to their plausible antioxidant and immune-stimulatory properties. This work was planned to explore the preventive function of AOS as a new bio-feed additive against the harmful effects caused by environmental HS on growing rabbits. Rabbits were allotted in four experimental groups (25 animals in each group) and fed on a basal diet supplemented with 0.0 (AOS0), 50 (AOS50), 100 (AOS100), and 150 (AOS150) mg AOS/kg diet reared under summer conditions. Dietary AOS supplementation improved significantly (P ≤ 0.001) feed conversion rate, while both AOS100 and AOS150 significantly (P ≤ 0.001) enhanced the final body weight and body weight gain. All AOS addition significantly increased nitric oxide and lysosome activity and significantly reduced interferon-gamma (IFNγ) compared with those in the control group. Tumor necrosis factor α (TNFα), interleukin1β (IL-1β), myeloperoxidase and protein carbonyl levels were significantly reduced in rabbits fed diets containing AOS (100 and 150 mg/kg) compared with those in the control group under heat stress conditions. In addition, glutathione (GSH) and catalase (CAT) were significantly (P ≤ 0.001) improved with increasing AOS dietary levels compared with the control group. Still, total antioxidant capacity (TAC), malondialdehyde (MDA), hematocrit, mean corpuscular volume (MCV), eosinophils, and lymphocytes did not change. Erythrocyte's indices improved significantly (P ≤ 0.001), while neutrophils and white blood cell counts were decreased by dietary AOS inclusion. Immunological (IgM and IgG) were markedly reduced in AOS-treated groups compared with the control group. The current investigation exemplified that AOS as a novel bio-feed additive that could be an effective strategy to extenuate prejudicial effects in heat-stressed rabbits via enhancing immunity, and antioxidant defence system, further regulating the inflammation cytokines.

Dietary soy galactooligosaccharides affect the performance, intestinal function, and gut microbiota composition of growing chicks

The objective of this experiment was to investigate the effects of the dietary soy galactooligosaccharides (GOS), raffinose and stachyose, on performance, gastrointestinal health, and systemic stress in young broilers. Birds were fed a GOS-devoid diet based on soy protein isolate (SPI) or the SPI diet with 0.9, 1.8, 2.7, or 3.6% added stachyose and raffinose in a ratio of 4:1 at the expense of corn starch. These 5 treatments were administered to 10 replicate cages of 8 birds. Performance was measured weekly and excreta moisture, N retention, apparent metabolizeable energy, and complete blood cell counts were determined at 14 and 21 d. At 21 d, 2 birds per cage were orally gavaged with fluorescein isothiocyanate-dextran (FITC-d) and serum samples were analyzed for FITC-d as a marker of gut leakage. Additionally, intestinal morphology, crop presumptive lactic acid bacteria (LAB) counts, crop and cecal pH, and cecal microbiota via16S rRNA microbial sequencing were evaluated at 21 d. From 0 to 21 d, feed intake increased linearly (P < 0.01) as dietary GOS increased, whereas BWG increased (P < 0.05) quadratically. Feed conversion ratio increased (P < 0.01) linearly as GOS increased. There were linear increases (P < 0.05) in excreta moisture as dietary GOS increased at 14 and 21 d, as well as dose-dependent responses (P < 0.05) in N retention, AME, and AME_n. There was a quadratic increase (P < 0.05) in crop LAB recovery and a linear decrease (P < 0.01) in ceca pH as GOS increased. At 14 d, a linear increase (P < 0.05) in blood heterophil to lymphocyte ratio was observed as dietary GOS increased. Serum concentrations of FITC-d increased quadratically (P < 0.01) to dietary GOS. Increasing levels of GOS influenced alpha and beta diversities and composition of gut microbiota, including the abundance of Ruminococcus and Bifidobacterium. Results from this trial indicate that soy-derived GOS exert dose-dependent effects on nutrient utilization and intestinal health in young broilers.

Soybean oligosaccharides combined with probiotics reduce faecal odour compound content by improving intestinal microbiota in pigs

As a potential prebiotic, soybean oligosaccharides (SBOS) can improve animal health by modulating gut microbiota. The aim of this study was to investigate the different effects of supplementing SBOS and supplementing SBOS plus probiotic on the growth and health of pigs. Three groups of growing pigs (n = 12) were fed with basal diet (Control), basal diet + 0.5% SBOS (SBOS), or basal diet +0.5% SBOS + 0.1% compound probiotics (SOP) for 42 days. Results showed that SBOS and SOP treatments had positive effects on the pigs in the experiment, and the latter was more effective. Compared with the control pigs, the average daily gain of SBOS group and SOP group slightly increased, SOP significantly increased the serum levels of growth hormone and thyroid hormone T3. Importantly, serum concentrations of immunoglobulin (IgA, IgG and IgM), total antioxidant capacity and superoxide dismutase in both treatments were increased significantly, SOP group most. Moreover, the faecal odour compounds of pigs, especially skatole, were significantly reduced by the treatments. Additionally, SOP significantly increased the diversity and richness of the faecal microbiota, both the treatments increased genera of norank_f_Muribaculaceae and Ruminococcaceae but reduced Lactobacillus. Correlation analysis indicated that Lactobacillus was significantly positively correlated with odour compounds, while Ruminococcaceae was the opposite. Conclusively, synbiotics combined with SBOS and probiotics had stronger promotion effects on the growth and health of pigs.

Effects of dietary oligosaccharides on serum biochemical index, intestinal morphology, and antioxidant status in broilers

In order to determine the effect of different oligosaccharides on growth performance, intestinal health, and antioxidant status of broilers, 240 1-day-old XiangHuang broilers were randomly distributed to 4 treatments with 6 replicates each. Birds were fed corn-soybean-based diets (CON), and birds in xylo-oligosaccharides (XOS), fructo-oligosaccharides (FOS), and iso-maltooligosaccharide (IMO) groups were given the basal diet supplemented with 200 mg/kg XOS, FOS, and IMO, respectively. Result showed that average daily gain (ADG) during the whole 5 weeks in FOS group was greater than that in control group (p < 0.05). Both breast and thigh muscle percentages were higher for birds fed XOS versus CON (p < 0.05). Oligosaccharides supplementation increased jejunal villus height compared with control group (p < 0.05). Malondialdehyde (MDA) concentration in breast muscle was lower for birds fed diet containing FOS versus CON (p < 0.05). Activities of total superoxide dismutase (T-SOD) in serum and thigh muscle were higher in IMO than in control group (p < 0.05). Serum T-SOD and breast muscle's glutathione peroxidase (GSH-Px) activity was higher in XOS compared with control group (p < 0.05). Conclusion, dietary oligosaccharides such as XOS, FOS, and IMO could improve intestinal health and antioxidant ability of muscle without affect growth performance in broilers.

In vitro fermentation profiles of different soybean oligosaccharides and their effects on skatole production and cecal microbiota of broilers

Objective

The objective of this study was to investigate the in vitro fermentation profiles of different soybean oligosaccharides (SBOs) and their effects on skatole production and cecal microbiota of broilers.

Methods

Five SBOs with varying main component contents were fermented using an in vitro batch incubation inoculated with broiler cecal microbiota. Gas production was recorded automatically, skatole, indole and short-chain fatty acids (SCFAs) were determined using high-performance liquid chromatography, and microbial changes were analyzed using 16S DNA gene sequencing.

Results

The addition of SBOs increased (p<0.05) gas production, suggesting bacterial growth-stimulating activities. In addition, the concentrations of indole were significantly (p<0.05) decreased after SBO supplementation, and SBO III, with higher sucrose and stachyose contents, decreased (p<0.05) the skatole level. Our results also revealed that the fermentation of SBOs by cecal microbiota produced (p<0.05) SCFAs, which were dominated by propionic acid, butyrate acid and lactic acid compared to the control. In addition, SBO III increased (p<0.05) the abundance of Firmicutes and Subdoligranulum and decreased that of Bacteroides.

Conclusion

These results suggest that SBOs with higher sucrose and stachyose contents are promising prebiotics in modulating gut microbiota and reducing odor emission in broilers.

Effect of trimmed asparagus by-products supplementation in broiler diets on performance, nutrients digestibility, gut ecology, and functional meat production

Background and Aim

Trimmed asparagus by-products (TABP) is the resultant waste from asparagus possessing. TABP has fructans, such as inulins and fructooligosaccharide, which can be utilized as an alternative prebiotic. This study was conducted to examine the effect of TABP dietary supplementation on the productive performance, nutrient digestibility, gut microbiota, volatile fatty acid (VFA) content, small-intestine histology, and meat quality of broilers.

Materials and Methods

A total of 320 1-day-old broiler chicks (Ross 308®) were raised under ambient temperature and assigned through a completely randomized design to one of four dietary treatments, with four replicates per treatment. The dietary treatments comprised corn-soybean basal diet supplemented with 0 (control), 10, 30, or 50 g/kg TABP. All birds were provided drinking water and feed ad libitum to meet the standard nutritional requirements of National Research Council for broiler chickens.

Results

TABP supplementation to the broilers significantly increased the apparent ether extract, crude fiber, and gross energy digestibility (p<0.05). TABP supplementation significantly increased lactic bacteria and Enterococcus spp. numbers as well as acetic, propionic, butyric, and total VFA levels (p<0.01); on the other hand, it also significantly decreased Salmonella spp. and Escherichia coli contents in the cecum compared with the control group (p<0.01). Moreover, TABP supplementation increased villus height in the duodenum and jejunum (p<0.01), cryptal depth in the jejunum and ileum (p<0.01), and villus surface areas in the duodenum, jejunum, and ileum (p<0.01). Overall, 0-35 day TABP supplementation significantly increased the feed intake (p<0.01) and average daily gain of broilers (p<0.05), but not significantly affected the viability, productive index, and economic benefit return (p>0.05). The carcass characteristics, pH, color, and water holding capacity of the chicken meat between groups were not significantly different (p>0.05). All levels of TABP supplementation appeared to be a feasible means of producing broilers with the lower serum low-density lipoprotein cholesterol and triglyceride levels as well as atherogenic indices of serum compared with the control (p<0.05). Cholesterol contents and palmitic acid, oleic acid, saturated fatty acids, and Monounsaturated fatty acids levels decreased with an increase of TABP supplementation (p<0.05). Furthermore, TABP supplementation decreased atherogenic index (AI) and thrombogenicity index (TI) of meat (p<0.05).

Conclusion

Supplementation of 30 g/kg TABP in broiler diet could enhance broiler performance and provide chicken meat with beneficial properties, with decreased AI and TI resulted from altered cholesterol and fatty acid profiles.

Effects of Dietary Glucose Oxidase Supplementation on the Performance, Apparent Ileal Amino Acids Digestibility, and Ileal Microbiota of Broiler Chickens

Simple Summary

Glucose oxidase was used as a potential additive to improve intestinal health in livestock and poultry industry. This study aimed to investigate the effects of glucose oxidase supplementation on performance, ileal microbiota, ileal short-chain fatty acids profile, and apparent ileal digestibility in grower broilers. Our findings will provide a valuable insight into the possibility of glucose oxidase as an alternative of antibiotic growth promoters in broiler diets.

Abstract

This study aimed to investigate the effects of glucose oxidase (GOD) supplementation on growth performance, apparent ileal digestibility (AID) of nutrients, intestinal morphology, and short-chain fatty acids (SCFAs) and microbiota in the ileum of broilers. Six hundred 1-day-old male broilers were randomly allotted to four groups of 10 replicates each with 15 birds per replicate cage. The four treatments included the basal diet without antibiotics (Control) and the basal diet supplemented with 250, 500, or 1000 U GOD/kg diet (E250, E500 or E1000). The samples of different intestinal segments, ileal mucosa, and ileal digesta were collected on d 42. Dietary GOD supplementation did not affect daily bodyweight gain (DBWG) and the ratio of feed consumption and bodyweight gain (FCR) during d 1-21 (p > 0.05); however, the E250 treatment increased DBWG (p = 0.03) during d 22–42 as compared to control. Dietary GOD supplementation increased the AIDs of arginine, isoleucine, lysine, methionine, threonine, cysteine, serine, and tyrosine (p < 0.05), while no significant difference was observed among the GOD added groups. The E250 treatment increased the villus height of the jejunum and ileum. The concentrations of secreted immunoglobulin A (sIgA) in ileal mucosa and the contents of acetic acid and butyric acid in ileal digesta were higher in the E250 group than in the control (p < 0.05), whereas no significant differences among E500, E1000, and control groups. The E250 treatment increased the richness of ileal microbiota, but E500 and E100 treatment did not significantly affect it. Dietary E250 treatment increased the relative abundance of Firmicutes phylum and Lactobacillus genus, while it decreased the relative abundance of genus Escherichina-Shigella (p < 0.05). Phylum Fusobacteria only colonized in the ileal digesta of E500 treated broilers and E500 and E1000 did not affect the relative abundance of Firmicutes phylum and Lactobacillus and Escherichina-Shigella genera as compared to control. These results suggested that dietary supplementation of 250 U GOD/kg diet improves the growth performance of broilers during d 22–42, which might be associated with the alteration of the intestinal morphology, SCFAs composition, and ileal microbiota composition.

Soybean oligosaccharides attenuate odour compounds in excreta by modulating the caecal microbiota in broilers

Abatement of odour emissions in poultry production is important to ensure the quality and safety in the poultry industry as well as for the benefit of the environment. This study was conducted to compare the effects of supplementation with different amounts of dietary soybean oligosaccharides (SBO) and chlortetracycline (CHL) on the major odour-causing compounds in the excreta and on the caecal microbiota in broiler chickens. One-day-old broiler chickens were subjected to a 42-day experiment involving 6 treatments with 6 replicates per treatment (10 birds/cage). The treatments were as follows: negative control (NC; basal diet), positive control (PC; basal diet supplemented with CHL) and basal diet supplemented with 0.5, 2.0, 3.5 and 5.0 g/kg SBO (0.5SBO, 2.0SBO, 3.5SBO and 5.0SBO, respectively). Fresh excreta were sampled for the analysis of odour compounds by HPLC. Caecum content was collected for the caecal microbiota analysis through 16S rRNA sequencing. Results showed that on day 42, the excreta indole concentration in the broilers fed with 2.0SBO, 3.5SBO and 5.0SBO and PC was significantly decreased (P < 0.01) compared with that in the NC-fed broilers. The excreta skatole concentration (P < 0.001) and pH (P < 0.05) were also decreased by SBO and CHL, and they were lowest in birds fed with 3.5SBO. The formate concentrations in birds fed with 3.5SBO and 5.0SBO were higher than those in birds fed with the other diets (P < 0.001). Similarly, acetate concentration (P = 0.003) was increased in birds fed with 3.5SBO. Deep sequencing of 16S rRNA revealed that the composition of the caecal microbial digesta was slightly or significantly changed by the SBO or by the CHL supplementation, respectively. The SBO supplementation decreased the abundance of Bacteroides, Bilophilaand Escherichia, which were associated with the skatole and indole concentrations in the excreta. By contrast, the CHL supplementation demonstrated a strong tendency to enrich Ruminococcus and to reduce the abundance of Rikenella. These results indicated that supplementation with dietary SBO is beneficial in attenuating the concentration of odour-causing compounds and that it modulates the composition of caecal microbiota in broiler chickens.

Dietary Inulin Supplementation Modulates Short-Chain Fatty Acid Levels and Cecum Microbiota Composition and Function in Chickens Infected With Salmonella

The current study investigated the effects of inulin on the gut microbiota, microbiome functions, and short-chain fatty acids (SCFAs) levels in specific pathogen-free (SPF) chickens infected with Salmonella enteritidis (SE). SPF Arbor Acres chickens (n = 240, 1-day-old) were divided into four groups: a control group (CON) fed a basal diet without inulin supplementation or SE infection, and three groups fed a basal diet supplemented with inulin 0, 0.5, and 1% (SE, 0.5%InSE, 1%InSE, respectively) up to 28-days-old, followed by SE challenge at 28 days of age. Cecal SCFA contents and microbiome composition and function were analyzed at 1-day post-infection. The results showed that SE infection significantly decreased cecal butyrate concentrations compared with the CON group (p < 0.05), while inulin supplementation reversed these changes compared with the SE group (p < 0.05). Inulin supplementation at 1% significantly increased the abundances of Lactobacillus and Streptococcus, and significantly decreased the abundances of Subdoligranulum and Sellimonas compared with the SE group (p < 0.05). The functional profiles of microbial communities based on metagenomic sequencing analysis showed that SE infection significantly increased the abundances of pathways related to carbohydrate metabolism, amino acid metabolism, energy metabolism, metabolism of cofactors and vitamins, and glycan biosynthesis and metabolism (p < 0.05), and significantly decreased the abundances of pathways related to nucleotide metabolism, translation, and replication and repair compared with the CON group (p < 0.05), and these effects were reversed by inulin supplementation (0.5 and 1%) (p < 0.05). In conclusion, inulin modulated the dysbiosis induced by SE infection via affecting SCFA metabolism and microbial functional profiles.

Effects of soybean oligosaccharide, stachyose, and raffinose on growth performance and cecal microbiota in broiler chickens

This study was conducted to examine the effects of soybean oligosaccharide, stachyose, and raffinose on growth performance and cecal microbiota in broiler chickens. Three-hundred 1-day-old Arbor Acres broiler chickens were randomly assigned to five dietary treatments: a basal diet (control diet); diets supplemented with soybean oligosaccharide, stachyose, or raffinose at levels of 0.6% total sugar content; and diet with soybean meals (positive control). Results showed that feed-to-gain ratio (F/G) was improved (p < 0.05) in broiler chickens that received stachyose, but not raffinose, while addition of soybean oligosaccharide to the diet significantly (p < 0.05) resulted in decreases in the average daily feed intake (ADFI) and average daily gain (ADG). Supplementation with soybean oligosaccharide, stachyose, or raffinose had a positive effect (p < 0.05) on the nutrient digestibility, but not on the blood immune parameters (p > 0.05). The results of the gene sequencing indicated that, at the family level, Ruminococcaceae, Lachnospiraceae, and Lactobacillaceae were comparatively present in all the treatments but the cecal microbial composition was changed after dietary addition of different oligosaccharides. Our study had led to a greater understanding of prebiotic effects of these oligosaccharides on growth and intestinal health.

Effects of dietary stachyose levels on caecal skatole concentration, hepatic cytochrome P450 mRNA expressions and enzymatic activities in broilers

Effects of dietary supplemental stachyose on caecal skatole concentration, hepatic cytochrome P450 (CYP450, CYP) mRNA expressions and enzymatic activities in broilers were evaluated. Arbor Acre commercial mixed male and female chicks were assigned randomly into six treatments. The positive control (PC) diet was based on maize-soyabean meal, and the negative control (NC) diet was based on maize-non-soyabean meal. The NC diet was then supplemented with 4, 5, 6 and 7 g/kg stachyose to create experimental diets, named S-4, S-5, S-6 and S-7, respectively. Each diet was fed to six replicates of ten birds from days 1 to 49. On day 49, the caecal skatole concentrations in the PC, S-4, S-5, S-6 and S-7 groups were lower than those in the NC group by 42·28, 23·68, 46·09, 15·31 and 45·14 % (P < 0·01), respectively. The lowest pH value was observed in the S-5 group (P < 0·05). The stachyose-fed groups of broilers had higher caecal acetate and propionate levels compared with control groups, and propionate levels in the S-6 and S-7 groups were higher than those in the S-4 and S-5 groups (P < 0·001). The highest CYP3A4 expression was found in the S-7 group (P < 0·05), but this was not different from PC, S-4, S-5 and S-6 treatments. There was no significant difference in CYP450 (1A2, 2D6 and 3A4) enzymatic activities among the groups (P > 0·05). In conclusion, caecal skatole levels can be influenced by dietary stachyose levels, and 5 g/kg of stachyose in the diet was suggested.

Assessment of Probiotic Properties of Lactobacillus salivarius Isolated From Chickens as Feed Additives

The continued use of sub-therapeutic antibiotics as feed additives in the poultry industry improved health and growth performance. However, the resulting antibiotic resistance increasingly becomes a major threat to public health. Probiotics are promising alternatives for the antibiotics used in poultry industry. The aim of this study was to evaluate the probiotic properties of Lactobacillus salivarius as feed additive in chickens. White leghorn chickens were randomly assigned to experimental groups. Effects of Lactobacillus salivarius supplementation on growth performance, resistance to Escherichia coli O78 challenge and heat-stress, and immune response after vaccinated with attenuated infectious bursal disease virus (IBDV) vaccine were determined. The results showed that Lactobacillus salivarius supplementation improved growth performance, such as weight and longer shank length, increased relative weights of the immune organs and decreased concentrations of odor-causing compounds. In addition, Lactobacillus salivarius supplementation alleviated organ injury caused by Escherichia coli O78 challenge and heat stress. Furthermore, Lactobacillus salivarius results in enhanced immune response after IBDV vaccine immunization, enhanced specific antibody and IFN-γ production, and lymphocyte proliferation. Our results revealed a tremendous potential of Lactobacillus salivarius as antibiotics' substitute in poultry production.

Soybean oligosaccharide, stachyose, and raffinose in broilers diets: effects on odor compound concentration and microbiota in cecal digesta

Soybean oligosaccharides have been previously shown to be associated with the production of major odor-causing compounds in broilers, although little is known about the role of stachyose and raffinose, which are key components of soybean oligosaccharide, in broiler cecal microbiota and odor compound production. To this end, soybean oligosaccharide, stachyose, and raffinose were added to the birds' diets to investigate their effects on odor compound production and the microbial community characteristics of the cecum in broilers. A total of 300 one-day-old Arbor Acre broilers with similar initial live weight were randomly allocated into 5 dietary groups with 6 replicates of 10 birds. The diets included soybean meal (positive control), soybean meal-free (negative control), 0.6% soybean oligosaccharide, 0.6% stachyose, or 0.6% raffinose. After a 49-D feeding period, both ceca were aseptically removed postmortem, and the contents were collected and analyzed for skatole, indole, volatile fatty acids, and lactic acid by using high performance liquid chromatography. Bacterial communities were detected by using a high-throughput sequencing platform based on IlluminaMiSeq 2500. Levels of skatole and indole tended to be lower in the dietary supplementation of oligosaccharides. The lowest levels of skatole and indole were observed in the stachyose group (P < 0.05), while the highest levels were found in the negative control group (P < 0.05). Concentrations of acetic acid and propionic acid in the stachyose group were increased (P < 0.05) while those of butyric acid and lactic acid were decreased (P < 0.05) compared with the soybean oligosaccharide and raffinose groups. Firmicutes and Bacteroidetes were prevalent in all groups, the proportion of Bacteroidetes was slightly decreased in the stachyose group, and Verrucomicrobia was abundant in the raffinose group (P > 0.05). Bacterial genera Alistipes and Parabacteroides were comparably abundant in the stachyose group, while Bacteroides, Lactobacillus, and Akkermansia were more abundant in the negative control, stachyose, and raffinose groups, respectively. Collectively, these findings demonstrated that dietary oligosaccharide supplementation significantly reduced odor compound production by modulating the cecal microbial community. Compared with soybean oligosaccharide and raffinose, the addition of stachyose into diets may help improve gut fermentation and minimize odor compound generation in broilers.

Effects of inulin supplementation on intestinal barrier function and immunity in specific pathogen-free chickens with Salmonella infection

We investigated the effects of inulin on intestinal barrier function and mucosal immunity in Salmonella enterica serovar Enteritidis (SE)-infected specific pathogen-free (SPF) chickens. SPF chickens (n = 240, 1-d-old) were divided into 4 groups (6 replicates per group, 10 chickens per replicate): a control group (CON) fed a basal diet without inulin supplementation and 3 SE-infected groups fed a basal diet supplemented with inulin 0% (SE group), 0.5% (0.5% InSE group), and 1% (1% InSE group), respectively. At 28 d of age, the chickens in SE-infected groups were orally infected with SE and in CON group were administrated with phosphated-buffered saline (PBS). Intestinal morphology, mucosal immunity, and intestinal barrier function-related gene expression were analyzed at 1- and 3-d post-infection (dpi). SE challenge significantly increased the mucosal gene expression, such as interleukin-1β (IL-1β), lipopolysaccharide-induced tumor necrosis factor factor (LITAF), interferon-γ (IFN-γ), and interleukin-6 (IL-6), and increased serum IFN-γ, secretory IgA (sIgA), and IgG concentration, and significantly decreased the gene expression levels of mucin 2 (MUC2) and claudin-1 at 3 dpi compared with the CON group (P < 0.05). Inulin supplementation improved the expression levels of these immunity- and intestinal barrier function-related genes, increased villus height (VH), and decreased crypt depth (CD) in the duodenum, jejunum, and ileum at 1 and 3 dpi within the SE-challenged groups (P < 0.05). SE challenge significantly increased ileal Toll-like receptor 4 (TLR4) mRNA at 1 and 3 dpi, suppressor of cytokine signaling 3 (SOCS3) mRNA at 1 dpi, and phospho-signal transducer and activator of transcription 3 (p-STAT3) and Janus kinase1 (JAK1) protein expression at 3 dpi compared with the CON group (P < 0.05). Inulin supplementation suppressed p-STAT3 and JAK1 protein expression and promoted ileal TLR4 and SOCS3 mRNA expression at 3 dpi compared with SE group (P < 0.05). In conclusion, inulin alleviated SE-induced gut injury by decreasing the proinflammatory response and enhancing mucosal immunity in chickens.

Spatial variations in intestinal skatole production and microbial composition in broilers

Spatial variations in intestinal skatole production and microbial composition in broilers were evaluated. Fifteen 42-day-old broilers were slaughtered. Samples were taken from the broilers' ileum, cecum, and rectum and analyzed for skatole levels. Denaturing gradient gel electrophoresis (DGGE) technique was used to analyze the microbial community from the intestinal digesta. The skatole levels could be arranged in decreasing order: cecum > rectum > ileum. Cecal lactate and acetate levels were higher than those of ileum and rectum (p < 0.01). Cecal microbial diversity and richness were higher than those of ileum (p < 0.05). One specific DGGE band was found in cecal sample and is closely related to Bacteroides uniformis. Cecum and rectum samples consisted of three coexistence bands, the related bacteria included Lactobacillus vaginalis and two members of Candidatus Arthromitus. The total bacterial population in cecum was higher than that in ileum and rectum (p < 0.05). Skatole levels were positively correlated with microbial Shannon-Wiener index, richness, total bacteria (p < 0.01) and Lactobacilli and Bifidobacterium (p < 0.05) populations. These results suggest that the variations in fermentation patterns are more likely to explain differences in intestinal skatole level. Bacteroides uniformis may play a role in the production of skatole.

The effects of inulin on the mucosal morphology and immune status of specific pathogen-free chickens

This study investigated the effects of inulin on mucosal morphology and immune function of specific pathogen-free (SPF) chickens. A total of 200 one-day-old White Leghorns SPF chickens were divided into 5 groups of 4 replicates of 10 chickens each. All SPF chickens were fed a basal diet supplemented with 0, 0.25, 0.5, 1.0, or 2.0% inulin. The mucosal morphology and immune indexes were analyzed on days 7, 14, and 21, respectively. Our results showed that the concentrations of acetate and propionate in the cecum and serum had increased with dietary inulin supplementation on day 21 (P < 0.05). Butyrate could not be detected in the cecal digesta, but was increased in the serum of 1 and 2% groups, as compared with the control group (P < 0.05). The villi height was increased (P < 0.05) and the crypt depth was decreased (P < 0.05) in the duodenum and ileum of SPF chickens fed inulin, as compared with the control group. Also, inulin at a low concentration (0.25 or 0.5%) significantly decreased (P < 0.05) the gene expression of nuclear factor-κB (NF-κB), lipopolysaccharide-induced tumor necrosis factor (LITAF) at 7, 14, and 21 d, and of interleukin-6 (IL-6), and inducible nitric oxide synthase (iNOS) at 7 and 14 d, and increased that of mucin 2 (MUC2) and claudin-1 in the ileum of SPF chickens at 7, 14, and 21 d. High inulin supplementation (2%) significantly increased the gene expression of NF-κB, LITAF, IL-6, iNOS, and Claudin-1 at 14 and 21 d compared to low inulin concentration (0.25 or 0.5%). The results indicated that the effects of inulin on mucosal immune function occurred in a dose-dependent manner. A low concentration (0.25 or 0.5%) of inulin may be beneficial in promoting intestinal immune function.

In vitro effects of inulin and soya bean oligosaccharide on skatole production and the intestinal microbiota in broilers

The experiment was conducted to investigate the in vitro effects of inulin and soya bean oligosaccharide (SBO) on the metabolism of L-tryptophan (L-try) to skatole production, and the intestinal microbiota in broilers. Treatments were as follows: caecal microbiota control (Cc), Cc + inulin, Cc + SBO, rectal microbiota control (Rc), Rc + inulin and Rc + SBO. Microbial suspensions were anaerobically incubated at 38°C for 24 hr. The results showed that concentrations of skatole and acetic acid were significantly lower in caecal microbiota fermentation broth (MFB) than those in rectal MFB (p < .05). Addition of inulin or SBO significantly decreased the concentrations of indole and skatole and rate of L-try degradation (p < .05). Inulin groups had lower indole than SBO groups (p < .05). PCR-DGGE analysis revealed that addition of inulin or SBO decreased the microbiota richness (p < .05), but no significant differences in Shannon index (p > .05). Four distinct bands were detected in inulin and SBO groups, which were related to two of Bacteroides, one of Firmicutes and Bifidobacteria. Six bands were detected only in control groups, which represented uncultured Rikenellaceae, Roseburia, Escherichia/Shigella dysenteriae, Bacteroides uniformis (T), Parabacteroides distasonis and Enterobacter aerogenes. Populations of Lactobacilli, Bifidobacteria and total bacteria in inulin groups were higher than those in control groups (p < .05). For SBO groups, only population of total bacteria increased (p < .05). However, there were no significant differences in Escherichia coli population among treatments (p > .05). These results suggest that reduced concentrations of skatole and indole in the presence of inulin and SBO may be caused by decrease in L-try degradation rate, which were caused by change in microbial ecosystem and pH value. Uncultured B. uniformis (T) and E. aerogenes may be responsible for degradation of L-try to skatole.