Effects of dietary Lactobacillus rhamnosus CF supplementation on growth, meat quality, and microenvironment in specific pathogen-free chickens

Gut microbes-muscle axis in muscle function and meat quality

The concept of the gut microbes-muscle axis underscores the impact of intestinal microbiota on the muscular system, an area that is increasingly coming to light. However, current interpretations and applications of this concept remain underdeveloped. In this review, we concluded and discussed factors, such as short-chain fatty acids, amino acids, vitamins, bile acids, antibiotics, cytokines, hormones, and extracellular vesicles that mediate gut microbes-muscle crosstalk and influence the gut microbes-muscle axis. Additionally, we examined how the gut microbes-muscle axis affects muscle mass, muscle strength, muscle metabolism, as well as muscle oxidative and immune status. Furthermore, we reviewed the influence of the microbes-muscle axis on muscle fiber type transition, muscle fat deposition, and meat quality. These insights illuminate the potential mechanisms by which the gut microbes-muscle axis operates in humans and animals. Thus, this review provides a theoretical foundation for future research and offers practical guidance for its application in biomedical and livestock industries.

Effects of Lactobacillus acidophilus on production performance and immunity of broiler chickens and their mechanism

Introduction

Lactobacillus species have attracted more and more attention as a potential antibiotic substitute for human health and animal production due to their remarkable antibacterial effects. However, the underlying mechanism is unclear. This experiment's goal was to investigate the impacts of lactic acid bacteria (LAB) on the growth performance, carcass characteristics, immune function of broiler chickens and their mechanism.

Methods

One hundred and eighty 1-day-old AA broilers were used and randomly allocated into 3 treatment groups with 6 replicates of 10 chickens per replicate. The 3 treatment groups were control group (CK), L. acidophilus added group (LAB-E, 1.0 × 108 CFU/kg) for the first 7 days; L. acidophilus added group (LAB-A, 1.0 × 108 CFU/kg) for the whole experimental period. Broilers had free access to water and feed.

Results

The results showed that addition of L. acidophilus for the whole experimental period significantly decreased ADFI, FCR and the abdominal fat percentage of broilers (p < 0.05), tended to increase the levels of IgG in broiler serum (p = 0.093). The LAB-A group had higher HDL-C content and IL-2, IL-4 content, and lower level of LPS in broiler serum compared to the controls (p < 0.05).

Discussion

In conclusion, L. acidophilus improved feed efficiency and immune function of broilers by controlling nutrient metabolism and inflammation responses of broilers. L. acidophilus can be used as a potential substitute for antibiotics in broiler production.

Lactic Acid Bacteria Surface Proteins in the Mechanisms of Cell Adhesion and Immunoregulation

This study delves into the role of lactic acid bacteria (LAB) surface proteins in cell adhesion and immunoregulation. Using fluorescence microscopy, we observed distinct adhesion patterns on various cell types. LAB surface proteins demonstrated concentration-dependent inhibition of Salmonella adhesion, with LAB69 exhibiting potent antagonistic effects. Genetic expression analysis revealed nuanced responses in key genes (MD2, TLR4, IL-10, MUC3, MIF) across different cell types, highlighting the diverse immunomodulatory effects of LAB surface proteins. Modulation of pro-inflammatory (TNF-α) and anti-inflammatory (IL-10) cytokines further emphasized the complex interplay. In conclusion, this study underscores the pivotal role of LAB surface proteins in mediating cell adhesion and immunoregulation, providing a foundation for isolating specific immunomodulatory molecules within LAB surface proteins for potential applications in microbial ecological agents.

Partial replacement of soybean with local alternative sources: effects on behavior, cecal microbiota, and intestinal histomorphometry of local chickens

Interest in partially replacing soybean meal in poultry diets with alternative protein sources such as agri-industrial by-products and black soldier fly (BSF, Hermetia illucens) has gained significant attention due to sustainability concerns. This study aimed to evaluate the effects of broiler diets in which soybean meal was partially substituted with agri-industrial by-products with or without BSF larvae meal, on the behavior, intestinal histomorphometry, and microbiome profile of a local broiler chicken strain. There were three dietary treatments. (1) A corn-soybean-based diet (Control), (2) a diet in which soybean was partly replaced (SPR) with local agri-industrial by-products, namely sunflower meal, brewers' dried grain, and wheat middlings, and (3) a diet in which BSF (5%) meal was added to SPR (SPR+BSF). Behavior was recorded on days 14, 35, and 49 at the pen level. On day 55, intestinal segments and cecal contents were collected from eight chickens per pen for histomorphometry and microbiome analysis. Dietary manipulations did not affect the behavior of broiler chickens (P > 0.05) suggesting that the experimental diets had no influence on behavior. A significant interaction between the intestinal segment and diets revealed that the SPR and SPR+BSF diets decreased duodenal villus height (VH) compared to the control diet (P < 0.05). However, this effect was not consistent across all of intestinal segments. Diet did not affect villus height to crypt depth ratio (VH/CD; P > 0.05), indicating no significant impact on the absorptive capacity of the digestive system. Firmicutes and Bacteroidetes were the dominant phyla in the cecal samples. Colidextribacter and Oscillibacter spp. were more abundant in chickens fed the SPR diet compared to those fed the control diet. The SPR+BSF diet resulted in higher abundance of Rikenella and Colidextribacter spp. compared to the control diet, while Desulfovibrio, Ruminococcus torques group, and Lachnoclostridium were more abundant in the ceca of birds fed the SPR diet than those fed SPR+BSF. In conclusion, replacement of soybean with agri-industrial by-products and BSF larvae meal could regulate the cecal microbiota composition without negatively affecting the behavior and intestinal histomorphometry of the local chickens.

Effects of Lactobacillus farciminis and Lactobacillus rhamnosus on the duodenal development of specific-pathogen-free broiler chickens

Background and Aim

The positive effects of Lactobacillus farciminis and Lactobacillus rhamnosus on growth and feed consumption indicators have been described; however, the underlying mechanisms remain unclear. This study aimed to determine whether the addition of L. farciminis CNCM-I-3699 (2.1010 GU/g) and L. rhamnosus CNCM-I-3698 (2.1010 GU/g) to the feed of Ross 308 specific-pathogen-free (SPF) broiler chickens (at a dose of 4 g/10 kg feed) affects live weight gain, the feed conversion ratio (FCR), and duodenal development in SPF broiler chickens.

Materials and Methods

In total, 780 SPF broiler chicks were randomly divided into two groups (three replicates per group) immediately after hatching: The control group (n = 390) and the probiotic group (n = 390). Live body weight (g) and FCR were measured on days 1, 7, 14, 21, 28, and 35 of the study. Histological examinations (hematoxylin and eosin staining) of the duodenum were performed, and the villus height (VH), villus width, crypt depth (CD), muscle layer thickness, and VH: CD ratio were measured. In addition, immunohistochemical examinations were performed to determine the number of proliferating cell nuclear antigen (PCNA)-positive cells.

Results

Feeding a probiotic mixture containing L. farciminis and L. rhamnosus to SPF broiler chickens for 35 days increased the duodenal absorption area and muscle layer thickness. In addition, it accelerated the histological development of the duodenum, as evidenced by the significantly higher number of PCNA-positive cells within the crypts. Although SPF broiler chickens in the ProL group exhibited greater live weight gain and lower FCR throughout the study, these differences were not statistically significant.

Conclusion

These results suggest that L. farciminis and L. rhamnosus can serve as additives to SPF broiler chicken feed to promote growth and development.

Effect of supplementation with Lactobacillus rhamnosus GG powder on intestinal and liver damage in broiler chickens challenged by lipopolysaccharide

This study explores the effect of dietary along with Lactobacillus rhamnosus GG (LGG) powder on intestinal and liver damage in broiler chickens challenged by lipopolysaccharide (LPS). A total of 100 healthy 1-day-old Ross 308 broiler chickens were selected and randomly divided into two treatments: the control group and the LGG treatment group. There were five replicates for each group, with 10 chickens per replicate. The chickens in the control group were fed a basal diet, while LGG treatment was supplemented with 1,000 mg/kg LGG along with the basal diet. The experiment lasted 29 days, and the trial included two phases. During the first 27 days, the animals were weighed on the 14th and 27th days to calculate growth performance. Then, on day 29, 2 animals from each replicate were intraperitoneally injected with 1 mg/kg BW LPS, and another 2 animals were treated with an equal volume of saline. The chickens were slaughtered 3 h later for sampling and further analysis. (1) LGG addition to the diet did not affect growth performance, including average daily gain (ADG), average daily feed intake (ADFI), and feed-to-weight ratio (F/G) of broiler chickens; (2) LPS stimulation decreased villus height (VH), and caused oxidative stress and increased the amount of diamine oxidase (DAO) in plasma, and the relative expression of intestinal inflammation genes (interleukin-8 [IL-8], interleukin 1β [IL-1β], inducible nitric oxide synthase [iNOS], and tumor necrosis factor-α [TNF-α]) and the relative expression of liver injury genes (b-cell lymphoma 2 [BCL2], heat shock protein70 [HSP70], and matrix metallopeptidase 13 [MMP13]). (3) Supplementation of LGG increased VH and the relative expression of intestinal barrier genes (mucins 2 [Mucin2] and occludin [Occludin]) and decreased the amount of DAO in plasma and the relative expression of intestinal inflammatory factors (IL-8, iNOS, and IL-1β). LGG supplementation also increased the expression of liver injury-related genes (MMP13 and MMP9). In conclusion, LGG enhanced intestinal barrier function, improved intestinal morphology, and alleviated the intestines' inflammatory response in LPS-stimulated broiler chicken, and it has a slightly protective effect on liver damage.

Insights into the evaluation, influential factors and improvement strategies for poultry meat quality: a review

Poultry meat, an essential source of animal protein, requires stringent safety and quality measures to address public health concerns and growing international attention. This review examines both direct and indirect factors that compromise poultry meat quality in intensive farming systems. It highlights the integration of rapid and micro-testing with traditional methods to assess meat safety. The paper advocates for adopting probiotics, prebiotics, and plant extracts to improve poultry meat quality.

Characteristics and health impacts of bioaerosols in animal barns: A comprehensive study

Bioaerosols produced during animal production have potential adverse effects on the health of workers and animals. Our objective was to investigate characteristics, antibiotic-resistance genes (ARGs), and health risks of bioaerosols in various animal barns. Poultry and swine barns had high concentrations of airborne bacteria (11156 and 10917 CFU/m3, respectively). Acinetobacter, Clostridium sensu stricto, Corynebacterium, Pseudomonas, Psychrobacter, Streptococcus, and Staphylococcus were dominant pathogenic bacteria in animal barns, with Firmicutes being the most abundant bacterial phylum. Based on linear discriminant analysis effect size (LEfSe), there were more discriminative biomarkers in cattle barns than in poultry or swine barns, although the latter had the highest abundance of bacterial pathogens and high abundances of ARGs (including tetM, tetO, tetQ, tetW sul1, sul2, ermA, ermB) and intI1). Based on network analyses, there were higher co-occurrence patterns between bacteria and ARGs in bioaerosol from swine barns. Furthermore, in these barns, relative abundance of bacteria in bioaerosol samples was greatly affected by environmental factors, mainly temperature, relative humidity, and concentrations of CO2, NH3, and PM2.5. This study provided novel data regarding airborne bio-contaminants in animal enclosures and an impetus to improve management to reduce potential health impacts on humans and animals.

Lactococcus G423 improve growth performance and lipid metabolism of broilers through modulating the gut microbiota and metabolites

This study aimed to explore whether Lactococcus G423 could improve growth performance and lipid metabolism of broilers by the modulation of gut microbiota and metabolites. A total of 640 1-day-old AA broilers were randomly divided into 4 groups [Control (CON), Lac_L, Lac_H, and ABX]. Average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio (FCR), breast muscle, thigh muscle, and abdominal fat pad were removed and weighed at 42 days of age. Serum was obtained by centrifuging blood sample from jugular vein (10 mL) for determining high-density lipoprotein (HDL), total cholesterol (TC), low-density lipoprotein (LDL), and triglyceride (TG) using ELISA. The ileal contents were harvested and immediately frozen in liquid nitrogen for 16S rRNA and LC-MS analyses. Then, the results of 16S rRNA analysis were confirmed by quantitative polymerase chain reaction (qPCR). Compared with the CON group, FCR significantly decreased in the Lac_H group (p < 0.05) in 1-21 days; ADG significantly increased and FCR significantly decreased in the Lac_H group (p < 0.05) in 22-42 days. 42 days weight body and ADG significantly increased in the Lac_H group (p < 0.05) in 42 days. Abdominal fat percentage was significantly decreased by Lactococcus G423 (p < 0.05), the high dose of Lactococcus G423 significantly decreased the serum of TG, TC, and LDL level (p < 0.05), and the low dose of Lactococcus G423 significantly decreased the serum of TG and TC level (p < 0.05). A significant difference in microbial diversity was found among the four groups. Compared with the CON group, the abundance rates of Firmicutes and Lactobacillus in the Lac_H group were significantly increased (p < 0.05). The global and overview maps and membrane transport in the Lac_L, Lac_H, and ABX groups significantly changed versus those in the CON group (p < 0.05). The results of LC-MS demonstrated that Lactococcus could significantly improve the levels of some metabolites (6-hydroxy-5-methoxyindole glucuronide, 9,10-DiHOME, N-Acetyl-l-phenylalanine, and kynurenine), and these metabolites were involved in four metabolic pathways. Among them, the pathways of linoleic acid metabolism, phenylalanine metabolism, and pentose and glucuronate interconversions significantly changed (p < 0.05). Lactococcus G423 could ameliorate growth performance and lipid metabolism of broilers by the modulation of gut microbiota and metabolites.

Using probiotics to improve nutrient digestibility and gut-health of weaned pigs: a comparison of maternal and nursery supplementation strategies

Maternal probiotic supplementation has been found to have a positive impact on the gut health of piglets, not only during the lactation period, but also after weaning. Providing probiotics to nursery pigs is also a common strategy for supplementation. The goal of this study was to evaluate which would be the most effective strategy to improve nutrient digestibility, energy metabolism, and intestinal health in weaned pigs considering the maternal or nursery options. A total of 32 newly weaned pigs were randomly split into a 2 × 2 factorial arrangement considering maternal probiotic supplementation (with or without) in gestation-lactation and probiotic supplementation in the nursery period (with or without). After weaning, experimental diets were provided for 22 days. Total fecal and urine collection was performed from day 15 to 21. Blood samples were collected from all pigs on days 3 and 22 of the experiment to assess serum biochemistry and intestinal permeability. All pigs were euthanized on day 22 for intestinal tissue collection. Pigs born from probiotic-fed sows had greater (p < 0.05) total tract digestibility of dry matter (+1%) and gross energy (+1.3%), and greater (p < 0.05) metabolizable energy coefficient (+1.3%), which resulted in a 46 kcal/kg increase (p < 0.05) in the metabolizable energy content of the diet. Nitrogen intake (p = 0.035), uptake (p = 0.007), and retention (p = 0.012) were all increased in these pigs. Fecal moisture was reduced in pigs born from probiotic-fed sows and pigs fed the probiotic diet only in the nursery (p < 0.05). Pigs born from probiotic-fed sows had reduced intestinal permeability by 16% (p < 0.05), whereas pigs fed the probiotic diet in the nursery only tended to improve this response (p < 0.10). The villus:crypt ratio of pigs born from probiotic-fed sows was greater compared to the control (p < 0.05), while serum levels of alanine aminotransferase were lower (p < 0.05). Pigs born from probiotic-fed sows had increased nutrient digestibility and improved gut health. Therefore, it is concluded that supplementing the sow diets with probiotics rather than just providing diets in the nursery phase is an advantageous strategy.

A combination of selenium and Bacillus subtilis improves the quality and flavor of meat and slaughter performance of broilers

This study aimed to investigate the effects of the combination of selenium and Bacillus subtilis (Se-BS) on the quality and flavor of meat and slaughter performance of broilers. A total of 240 one-day-old Arbor Acres broilers were randomly allotted to four treatments of a basal diet supplemented with no selenium (control), sodium selenite (SS), BS, or Se-BS and raised for 42 days. Compared with the control group, Se-BS significantly increased the carcass weight, the half-eviscerated weight, the completely eviscerated weight, the carcass rate, and redness in broiler muscles; improved the antioxidant state by increasing glutathione peroxidase (GPx) and glutathione S-transferase activities, the total antioxidant capacity, and GPx-1 and thioredoxin reductase 1 messenger RNA (mRNA) levels; promoted biological activity by increasing the contents of glutamate, phenylalanine, lysine, and tyrosine; and increased Se and five types of nitrogenous volatile substances in muscles. On the other hand, Se-BS treatment decreased the shear force, drip loss, and the malondialdehyde, glutathione, and lead contents in muscles. Se-BS exerted a better effect on slaughter performance, the physicochemical quality of meat, the redox status, the amino acid contents, the trace element contents, and volatile substances compared with SS and BS. In conclusion, Se-BS had a positive effect on the quality and flavor of meat and slaughter performance of broilers, suggesting that Se-BS may be a beneficial feed additive.

Evaluation of the Efficacy of Enterococcus faecium L3 as a Feed Probiotic Additive in Chicken

The study was devoted to the comparison of the probiotic effect of enterococcal Enterococcus faecium L3 to the antibiotic enramycin as a chicken feed additive. Two hundred and sixteen chickens were divided into three groups and tested by different parameters including weight gain, food consumption, blood biochemistry, immunology, and caecal microbiome at two checkpoints, 21 and 39 days after birth. By the end of the experiment, a group of chickens getting probiotic demonstrated weight gain of more than 100 g at the average relative to the control group with no additive in animal feed (P < 0.05). Blood serum biochemistry showed a significant increase in HDL level (P < 0.05) relative to the control group. The 16S RNA sequencing demonstrated the growth abundance of Lachnospiraceae and the decrease of Proteobacteria in probiotic fed group. On the contrary, the antibiotic fed group showed a noticeable increase in the abundance of Proteobacteria which included the genus Salmonella. Thus, probiotic E. faecium L3 being added to chicken food as a single additive may be considered as a possible replacement of antibiotic enramycin.

Effects of blackcurrant extract on indole and ammonia productions in an in vitro human fecal culture model

Blackcurrant is available as a traditional medicine in Europe. However, the detailed effects of blackcurrant on the human gut microbiota remain unknown. In this study, we investigated the prebiotic effects of a blackcurrant extract using a human fecal culture model in six healthy subjects. Feces were individually inoculated into a medium with or without the blackcurrant extract and then fermented for 48 hr under anaerobic conditions. The results obtained from analysis of samples from the fermented medium demonstrated that after 48 hr of fermentation, the pH of the medium with the blackcurrant extract was significantly decreased (control, 6.62 ± 0.20; blackcurrant extract, 6.41 ± 0.33; p=0.0312). A 16S rRNA gene sequencing analysis of the microbiota of the fermented medium showed a significant increase in the relative abundance of Bifidobacteriaceae. In measuring the concentrations of putrefactive components in the fermented medium, we found that the blackcurrant extract significantly reduced ammonia levels and displayed a tendency toward reduced indole levels. Our results suggest that blackcurrant extract could be a potential ingredient for relief of putrefactive components in the gut.

The Effects of Lactobacillus farciminis and Lactobacillus rhamnosus on Growth, Blood Biochemical, and Meat Quality Indicators of Specific Pathogen-Free Broiler Chickens

The aim of our study was to evaluate the effects of Lactobacillus farciminis and Lactobacillus rhamnosus on live weight gain, feed consumption indicators, and some metabolic blood biochemical and meat quality indicators of specific pathogen-free Ross 308 broiler chickens. We carried out the study in three trials and included a total of 780 unsexed Ross 308 chickens, which we randomly divided into two groups: the control group (Con, n = 390, basal diet) and the probiotic group (ProL, n = 390, basal diet + a powder consisting of L. farciminis and L. rhamnosus 4 g/10 kg of feed). We raised broilers until day 35. We determined the amount of feed consumed, the average daily weight gain, the feed conversion ratio, the average daily feed intake, and the cumulative feed intake once a week. We collected blood samples from 45 broilers from each group at the end of the study. In addition, we slaughtered 30 broilers from each group by cervical dislocation to obtain a breast muscle sample (without skin) to determine meat quality in these chickens (cholesterol and unsaturated, omega-3, omega-6, omega-9, and saturated fatty acids). Feeding a probiotic mixture containing L. farciminis and L. rhamnosus did not significantly affect the growth and feed intake indicators. Feeding these probiotics significantly lowered the blood serum cholesterol levels but did not provide the expected reduction in meat cholesterol levels. However, feeding a probiotic mixture increased the levels of polyunsaturated fatty acids (omega-3 and omega-6 fatty acids) in the breast meat and decreased saturated fatty acids. To better explain the effect of the combination of lactic acid bacteria (L. farciminis and L. rhamnosus) on the growth and development of broiler chickens in our study, histological and immunohistochemical examinations should be performed.

Effects of Lactobacillus plantarum and its Fermentation Products on Growth Performance, Immune Function, Intestinal pH and Cecal Microorganisms of Lingnan Yellow Chicken

The present research was conducted to investigate the effects of dietary supplementation of Lactobacillus plantarum and its fermentation products on growth performance, specific immune function, intestinal pH, and cecal microorganisms in yellow-feather broilers. A total of 1,200 yellow-feather broilers of similar weight and good health condition at 1 d of age were selected and randomly divided into 5 groups. The CK group was fed the basal diet, and the experimental group (I, II, III, IV) were supplemented with 0.1, 0.15% L. plantarum and 3, 4% L. plantarum fermentation products. The results showed that each treatment could improve the growth performance (P < 0.05) and feed conversion rate of yellow-feather broilers. Besides, the pH value of the gastrointestinal tract of yellow-feather broilers (P < 0.05) was significantly reduced through the use of L. plantarum and its fermentation products as additives, which also facilitated the animals to regulate the balance of cecal microorganisms. The immune function assay showed that the bursal index (P < 0.05), spleen index (P < 0.05), and the content of serum immunoglobulins IgA and IgG (P < 0.05) were significantly increased in yellow-finned broilers aged 1 to 21 d by supplementing the diet with L. plantarum. In conclusion, adding L. plantarum or its fermentation products to the diet can improve the growth performance of yellow-feather broilers, and the direct addition of L. plantarum is better than adding fermentation products.

Lactobacillus (L. plantarum & L. rhamnosus) and Saccharomyces (S. cerevisiae): effects on performance, biochemical parameters, ammonium ion in manure, and digestibility of broiler chickens

Two strains of Lactobacillus combined with Baker's yeast (Saccharomyces cerevisiae) used as probiotics were evaluated to replace antibiotics in poultry flocks by reducing ammonia emissions in manure of broilers without comprising performance or health. One-day-old Cobb 500 broilers (600) were fed starter, grower, and finisher diets as control (CON); probiotic S. cerevisiae, inclusion rate at 4.26 × 10⁶ CFU/kg of feed (SCY); probiotic L. plantarum and L. rhamnosus, inclusion rate at 4.35 × 10⁸ CFU/kg of feed (LPR) for each; and a combination of Lactobacillus plantarum and L. rhamnosus at 4.35 × 10⁸ CFU/kg of feed for each plus Saccharomyces cerevisiae and 4.26 × 10⁶ CFU/kg of feed (SWL). The 4 treatments had 5 replicates (pens), each with 30 broilers. Performance was measured weekly as feed consumption, weight gain, BW, and feed conversion ratio (FCR) over a 6-wk grow-out period. Accompanying biochemical analyses included lipase activity of the pancreas, liver weight, and uric acid (UA) concentration in liver. Albumin, total protein, UA, ammonia, and blood urea nitrogen (BUN) were measured in serum. Ammonium (NH₄⁺) in manure and apparent ileal digestibility from digesta were also measured. Significance was determined at P ≤ 0.05. Results showed that biochemical analyses had no significant treatment effect; however, there were significant temporal changes in performance measures for individual treatments. Feed consumption increased over time for all treatments (P = 2.00 × 10^-16). CON had lower weight gain in wk 2 (P = 0.013) compared to all treatment and the lowest BW in wk 5 (P = 0.0008) and wk 6 (P = 0.0124) compared to SWL. Specific probiotic strains, with well-defined inclusion rates, and surrounding environmental analyses of present microbes are needed to ascertain effects of probiotics. Other important areas for investigation include 1) confirmation of probiotics present in the digesta/ceca and how they alter the microbiota within the gastrointestinal (GI) tract and 2) the serum heterophil:lymphocyte ratio to further examine potential immune responses to the probiotics.

Potential Mechanism and Effects of Different Selenium Sources and Different Effective Microorganism Supplementation Levels on Growth Performance, Meat Quality, and Muscle Fiber Characteristics of Three-Yellow Chickens

A trial was conducted to investigate the effects of different Se sources, including sodium selenite (S-Se) and selenium yeast (Y-Se) and different effective microorganism (EM) addition levels on growth performance, meat quality, and muscle fiber characteristics of three-yellow chickens and its potential mechanism. A total of 400 birds were randomly distributed into 4 groups (S-Se, S-Se + EM, Y-Se, and Y-Se + EM groups) consisting of a 2 × 2 factorial arrangement. The main factors were the source of Se (I_Se = inorganic Se: 0.2 mg/kg S-Se; O_Se = organic Se: 0.2 mg/kg Y-Se) and the level of EM (H_EMB = high EM: 0.5% EM; Z_EMB = low EM: 0% EM). Each treatment had 5 replicates and each replicate consisted of 20 broiler chickens. The trial lasted for 70 days. The results showed that, in breast muscle, the broiler chickens fed O_Se source decreased the pH_24h, drip loss, shear force, perimeter, cross-sectional area, and diameter, but increased the a24h* and density compared with the broiler chickens fed I_Se source (p < 0.05); broiler chickens supplied with H_EMB level decreased the cross-sectional area and diameter, but increased the pH_24h, a24h,* and density compared with the broiler chickens supplied with Z_EMB level (p < 0.05). In thigh muscle, O_Se source and H_EMB level also could improve the meat quality and change muscle fiber characteristics of broiler chickens (p < 0.05). Meat quality was correlated with the muscle fiber characteristics (p < 0.05). O_Se source and H_EMB level could regulate the expression levels of muscle fiber-relative genes in the breast and thigh muscles (p < 0.05). In conclusion, O_Se source and H_EMB level could improve the meat quality of the breast and thigh muscles of three-yellow chickens by changing the muscle fiber characteristics, and they changed the muscle fiber characteristics by regulating the expression levels of muscle fiber-relative genes.

Dietary administration of Bacillus subtilis KC1 improves growth performance, immune response, heat stress tolerance, and disease resistance of broiler chickens

The purpose of the present study was to evaluate the probiotic properties of Bacillus subtilis KC1 as a feed additive in the poultry feed. Effects of the Bacillus subtilis supplementation on growth performance, heat-stress tolerance, resistance to Mycoplasma gallisepticum (MG) and Salmonella Pullorum challenge of broilers were determined. The protective effects of the Bacillus subtilis on liver function and immune response of broilers challenged with Aflatoxin B1 (AFB1) were also scrutinized. The results showed that the Bacillus subtilis supplementation could improve growth performance, increased body weight, relative weight of the immune organ and dressing percentage, and decrease feed conversion ratio. In addition, the Bacillus subtilis supplementation alleviated adverse effects caused by heat stress, MG, and Salmonella Pullorum challenge. Furthermore, the Bacillus subtilis supplementation resulted in improved liver function and enhanced immune response of broilers challenged with AFB1. In conclusion, these results suggested a tremendous potential of Bacillus subtilis KC1 as a feed additive in the poultry feed.

Modified Black Soldier Fly Larva Fat in Broiler Diet: Effects on Performance, Carcass Traits, Blood Parameters, Histomorphological Features and Gut Microbiota

Simple Summary

Black soldier fly (Hermetia illucens L.; BSF) is gaining interest as a functional feed additive, due to the high amount of medium-chain fatty acids (MCFAs) and monoglycerides, which provide antimicrobial activities and stimulate gastrointestinal health through inhibition of potentially pathogenic bacteria. The present study evaluated the effect of BSF and modified BSF larvae fat in broiler chicken’s diet. Overall results were comparable among the studied diets, suggesting that modified BSF larvae fat showed a positive modulation of fecal microbiota by a positive reduction in potentially pathogenic bacteria such as Clostridium and Corynebacterium, without affecting intestinal morphology or showing any adverse histopathological alternations.

Abstract

In this study, a total of 200 male broiler chickens (Ross 308) were assigned to four dietary treatments (5 pens/treatment and 10 birds/pen) for two feeding phases: starter (0–11 days of age) and grower-finisher (11–33 days of age). A basal diet containing soy oil (SO) as added fat was used as control group (C), tested against three experimental diets where the SO was partially substituted by BSF larvae fat (BSF) or one of two types of modified BSF larvae fat (MBSF1 and MBSF2, respectively). The two modified BSF larvae fats had a high and low ratio of monobutyrin to monoglycerides of medium chain fatty acid, respectively. Diet did not influence the growth or slaughter performance, pH, color, or the chemical composition of breast and thigh muscles, gut morphometric indices, or histopathological alterations in all the organs. As far as fecal microbiota are concerned, MBSF1 and MBSF2 diets reduced the presence of Clostridium and Corynebacterium, which can frequently cause infection in poultry. In conclusion, modified BSF larva fat may positively modulate the fecal microbiota of broiler chickens without influencing the growth performance and intestinal morphology or showing any adverse histopathological alternations.

Dietary Supplementation of Potential Probiotics Bacillus subtilis, Bacillus licheniformis, and Saccharomyces cerevisiae and Synbiotic Improves Growth Performance and Immune Responses by Modulation in Intestinal System in Broiler Chicks Challenged with Salmonella Typhimurium

This study evaluates the effects of probiotics and synbiotics on the performance, immune responses, and intestinal morphology, and the expression of immunity-related genes of broiler chicks challenged with Salmonella typhimurium. Three hundred and sixty broiler chicks were divided into six groups, including broiler chicks challenged and non-challenged with S. typhimurium and fed with probiotic, synbiotic, and basal diet without additive. Growth performance (food intake, daily gain, feed conversion ratio, and mortality), immune responses (antibody titer against sheep red blood cells, immunoglobulins G and M), intestinal morphology, lactic acid bacteria population, and the expression of immunity-related genes (interferon-γ, interleukins 6 and 12, and tumor necrosis factor-α) were investigated. The administration of S. typhimurium decreased growth performance (P = 0.0001), immune responses (P = 0.0001), intestinal morphology (P = 0.0001), lactic acid bacteria population (P = 0.0001), and the expression of immunity-related genes (P = 0.0001) of broiler chickens. However, broiler chicks fed with probiotic (P = 0.001) and synbiotic (P = 0.0001) showed better growth performance, immune responses, intestinal morphology, lactic acid bacteria population, and the expression of immunity-related genes in comparison with infected broiler chicks fed with basal diet lack of probiotic and synbiotic. Feeding probiotics (P = 0.001) and synbiotics (P = 0.0001) showed positive effects for challenged and non-challenged broiler chicks. In sum, feeding synbiotic and probiotic alleviated the negative effects of S. typhimurium on growth and immunity of broiler chicks. It can be suggested to apply synbiotic and probiotics as benefit additive against infectious challenges, such as S. typhimurium.

Lactobacillus ingluviei C37 from chicken inhibits inflammation in LPS-stimulated mouse macrophages

Probiotics are growing alternatives to antibiotics, and can contribute to the prevention and treatment of diseases and enhance livestock production. Lactobacillus (L.) ingluviei is a novel probiotic species with growth-enhancement effects; however, this species remains poorly understood, and there have been (to our knowledge) no studies focusing on its immunological effects. Here, we isolated L. ingluviei C37 (LIC37) from chicken and evaluated the bacterium's immunomodulatory properties to explore its probiotic potential. Real-time quantitative PCR and ELISA showed that in vitro exposure of inflammation-stimulated mouse peritoneal macrophages to heat-killed LIC37 led to decreases in tumor necrosis factor-α and interleukin (IL)-6 levels and an increase in IL-10. These findings suggested that LIC37 exerts anti-inflammatory effects by modulating cytokine profiles. This species may be an attractive probiotic bacterial strain for use in animal production.

Effects of dietary inclusion of Lactobacillus and inulin on growth performance, gut microbiota, nutrient utilization, and immune parameters in broilers

The effects of dietary Lactobacillus (BCRC 16092) and inulin on growth performance, intestinal microflora, mineral utilization, and tissue mineral contents were evaluated in broilers. The experiment was conducted using 1,152 one-day-old broilers randomly distributed to 9 treatments in a factorial arrangement (3 × 3) using 3 levels of inulin (0, 1, and 2%) and 3 levels of Lactobacillus addition (108, 109, and 1010 CFU/kg). Broilers (1 D of age; 8 replicates per treatments and 16 broilers per replicate) with an initial body weight of 48.36 ± 0.21g were evaluated for 42 D. A 4-D mineral digestibility trial was conducted during the final week of the experiment. The results showed that Lactobacillus supplementation can increase average daily gain and nutrient digestibility and improve feed/gain in broilers (P < 0.05). Moreover, Lactobacillus and inulin supplementation increased the numbers of Lactobacillus and Bifidobacteria, increased serum concentration of IgG and IgA, and decreased the numbers of Escherichia coli and pH in ileum and cecum. The present study demonstrated Lactobacillus and inulin fed to broilers has a positive effect on gut microbiota, growth and nutrient utilization, immune system, and mineral metabolism.

Effect of a Synbiotic Mix on Intestinal Structural Changes, and Salmonella Typhimurium and Clostridium Perfringens Colonization in Broiler Chickens

Synbiotics can prevent gastrointestinal infections in broilers. This work studies the effect of a Synbiotic on broilers. One-day-old male broilers were divided into groups: Control; Synbiotic; Synbiotic + S. Typhimurium; Synbiotic + C. perfringens; Synbiotic + S. Typhimurium + C. perfringens; S. Typhimurium; C. perfringens; and S. Typhimurium + C. perfringens. Histopathological analysis revealed that the Synbiotic promoted longer villi, less deep crypts, and better villi-crypt ratio. Broilers treated with the Synbiotic, infected with pathogens or not, had healthier mucosa. In groups infected with pathogens, the frequency and intensity of histopathologic lesions were lessened often in groups treated with the Synbiotic. The Synbiotic group had higher lactic acid bacteria counts than the Control group on day 39, and the isolation frequency of S. Typhimurium was lower (p < 0.05) in the Synbiotic-treated groups. On day 18, mucosa, villi, villi-crypt ratio, crypt, and feed intake were influenced by Enterobacteriaceae. However, on day 39 (end of the trial), those parameters were influenced by lactic acid bacteria. The Synbiotic influenced morphological modifications in the duodenal mucosa, which in turn gave the broilers the ability to resist infections caused by S. Typhimurium and C. perfringens, by inhibiting their growth and decreasing the intensity and frequency of histopathological injuries.

Effects of Bacillus subtilis C-3102 on production, hatching performance, egg quality, serum antioxidant capacity and immune response of laying breeders

To investigate the supplemental effects of Bacillus subtilis C-3102 on the production, hatching performance, egg quality, serum antioxidant capacity and immune response of laying breeders, a total of 480 Xuefeng black-bone (25-week-old) hens were randomly assigned into four treatment groups: Hens fed the basal diets with 0 (CON), 3.0 × 10⁵ (BS-1), 6.0 × 10⁵  cfu/g (BS-2) and 9.0 × 10⁵ (BS-3) cfu/g of B. subtilis C-3102. As the B. subtilis C-3102 level increased, egg weight (linear, p < 0.01; quadratic, p = 0.003), fertility (linear, p = 0.021; quadratic, p = 0.059), hatchability (linear, p = 0.038; quadratic, p = 0.119) and yolk colour (linear, p = 0.006; quadratic, p = 0.021) increased in a linear or quadratic manner. Yolk index increased quadratically (linear, p = 0.054; quadratic, p = 0.017), and eggshell thickness (linear, p = 0.036; quadratic, p = 0.128), the activity of GSH-Px (linear, p = 0.024; quadratic, p = 0.078), the concentration of IgM (linear, p = 0.016; quadratic, p = 0.056) and the level of AIV-Ab (linear, p = 0.034; quadratic, p = 0.103) in the serum increased linearly as dietary supplementation of B. subtilis C-3102 increased. The results showed that dietary treatments did not affect egg production, feed conversion ratio, egg mass, hatchability of fertile eggs, eggshell-breaking strength, egg-shape index, yolk percentage, Haugh unit, T-SOD, T-AOC, MDA, IgA and IgG concentrations and the level of NDV-Ab in the serum. In conclusion, dietary supplementation of 9.0 × 10⁵  cfu/g B. subtilis C-3102 in laying breeders diets may be a feasible means of effectively increasing egg weight, fertility and hatchability, and improving egg quality such as eggshell thickness, yolk index and yolk colour. Besides, B. subtilis C-3102 can enhance the activity of GSH-Px, the concentration of IgM and the level of AIV-Ab in the serum.

Combined Use of C. butyricum Sx-01 and L. salivarius C-1-3 Improves Intestinal Health and Reduces the Amount of Lipids in Serum via Modulation of Gut Microbiota in Mice

The study was conducted to investigate whether combined use of C. butyricum Sx-01 and L. salivarius C-1-3 could improve the intestinal health and reduce the lipid levels in sera of mice and whether these benefits were related to regulating the intestinal microflora. Eighty Kunming male mice were divided into four groups with five replicates per group and four mice per replicate. Mice in the control group were administrated with 0.2 mL normal saline; mice in three experimental groups were daily orally administrated with 4 × 10⁸ cfu of L. salivarius, 4 × 10⁸ cfu of C. butyricum, and a combination thereof (2 × 10⁸ cfu of L. salivarius, and 2 × 10⁸ cfu of C. butyricum), respectively. The experiment lasted for 14 days. The results showed that the average daily feed intake (ADFI) and feed/gain (F/G) ratio of growing mice underwent no significant changes (p > 0.05); however, the average daily gain (ADG) tended to increase over short periods of time. The activities of SOD and GSH-Px in serum in the combination group were significantly increased (p < 0.05); The triglyceride, and total cholesterol, contents in serum in the combined treatment group were significantly decreased (p < 0.05); The total volatile fatty acids and butyric acid in faecal matter of mice in the experimental groups were all significantly increased at 14 days (p < 0.05); The length of villi, and the mucosal thickness of colon and caecum (p < 0.05) were significantly improved; The relative abundance of some bacteria with antioxidant capacity or decomposing cholesterol capacity or butyrate producing capacity was increased, while the relative abundance of some pathogenic bacteria was decreased in the colon. Furthermore, our results showed that the beneficial effects of the combined use of the two strains was higher than that of single use. Overall, the results demonstrated that the combined use of C. butyricum Sx-01 and L. salivarius C-1-3 can significantly improve intestinal health and reduce the amount of lipids in sera of mice. The reason for these effects might be that besides their own probiotic effects, combined use of the two strains could regulate the intestinal microflora.