Effects of yeast cultures with different fermentation times on the growth performance, caecal microbial community and metabolite profile of broilers

Efficacy of Bacillus subtilis to replace in-feed antibiotics of broiler chickens under necrotic enteritis-challenged experiments: a systematic review and meta-analysis

Necrotic enteritis (NE) and coccidiosis are among the most prevalent infectious diseases in broiler chickens, contributing to large profitability losses. Bacillus subtilis is a promising direct-fed probiotic to counter various pathogens infection in broiler chickens. Here, we performed a meta-analysis to investigate the effects of B. subtilis on broiler chickens performance. A total of 28 studies were selected according to a PRISMA checklist. Random-effect model and mixed-effect model of meta-analysis were fitted to estimate the overall effects of B. subtilis (BS) treatment compared to either the control group (CON) or NE-infected group (NEinf) as a baseline. Hedges' g effect size and its variance were used as estimators of standardized mean difference (SMD) calculation where the results were presented at a 95% confidence interval (95% CI) of the SMD. Overall, NEinf broiler chickens depressed (P < 0.01) body weight (BW), average daily gain (ADG), and feed intake, and elevated (P < 0.01) feed conversion ratio (FCR). Treatment with BS improved ADG and final BW of NEinf with no difference (P = 0.15) between BS and antibiotics (AB), indicating that they had comparable efficacy to treat NE in broiler chickens. BS supplemented to uninfected CON (BSS) improved (P < 0.01) final BW, ADG, and FCR. Compared to CON, BS, and AB failed to recover the FCR but these treatments decreased (P < 0.01) FCR when compared to the NEinf group with similar efficacy (P = 0.97). As expected, NEinf birds had a higher mortality rate (P < 0.01) and higher lesion score (P < 0.01) compared to CON, and treatment using AB and BS successfully decreased (P < 0.01) the mortality rate and lesion score. Compared to BS, AB was more effective to lower (P = 0.01) mortality rate, but comparable (P = 0.65) to minimize lesion score. To conclude, B. subtilis could be an effective natural additive to replace in-feed antibiotics in broiler chickens challenged with C. perfringens. However, the efficacy to reduce mortality rate was better with antibiotics treatment.

Yeast-Derived Products: The Role of Hydrolyzed Yeast and Yeast Culture in Poultry Nutrition—A Review

Simple Summary

Yeast and yeast-derived products are largely employed in animal nutrition to support animals’ health and to improve their performance. Thanks to their components, including mannans, β-glucans, nucleotides, vitamins, and other compounds, yeasts have numerous beneficial effects. Among yeast-derived products, hydrolyzed yeasts and yeast cultures have received less attention, but, although the results are somewhat conflicting, in most of the cases, the available literature shows improved performance and health in poultry. Thus, the aim of this review is to provide an overview of hydrolyzed-yeast and yeast-culture employment in poultry nutrition, exploring their effects on the production performance, immune response, oxidative status, gut health, and nutrient digestibility. A brief description of the main yeast bioactive compounds is also provided.

Abstract

Yeasts are single-cell eukaryotic microorganisms that are largely employed in animal nutrition for their beneficial effects, which are owed to their cellular components and bioactive compounds, among which are mannans, β-glucans, nucleotides, mannan oligosaccharides, and others. While the employment of live yeast cells as probiotics in poultry nutrition has already been largely reviewed, less information is available on yeast-derived products, such as hydrolyzed yeast (HY) and yeast culture (YC). The aim of this review is to provide the reader with an overview of the available body of literature on HY and YC and their effects on poultry. A brief description of the main components of the yeast cell that is considered to be responsible for the beneficial effects on animals’ health is also provided. HY and YC appear to have beneficial effects on the poultry growth and production performance, as well as on the immune response and gut health. Most of the beneficial effects of HY and YC have been attributed to their ability to modulate the gut microbiota, stimulating the growth of beneficial bacteria and reducing pathogen colonization. However, there are still many areas to be investigated to better understand and disentangle the effects and mechanisms of action of HY and YC.

Dietary Supplementation of a New Probiotic Compound Improves the Growth Performance and Health of Broilers by Altering the Composition of Cecal Microflora

Simple Summary

In most countries, antibiotic growth promoters are restricted or banned in the livestock industry, and probiotics have been widely explored to replace them. Lactobacillus LP184 and Yeast SC167 were selected as probiotic strains that could remain viable in feed and the gastrointestinal tract and were combined to form a compound to act as a substitute for antibiotics in broilers’ diets. This study aimed to investigate the effects of the compound probiotics as a potential alternative to antibiotics in broiler production. The feeding trial contained three dietary treatments and lasted for 42 days. The negative control group was fed the basal diet. The positive control group was fed the basal diet supplemented with commercial antibiotics. The probiotics group was fed the basal diet containing the compound probiotics. The results showed that the compound probiotics were a competent alternative for synthetic antibiotics to improve the production of broilers. The compound probiotics enhanced the immune and antioxidant capacities of broilers, which could not be achieved using antibiotics. The positive effects of the compound probiotics on the growth performance and health of broilers can likely be attributed to the improvement of intestinal morphology and cecal microbial diversity, effects which are distinct from those of antibiotics. These findings demonstrate the feasibility of replacing antibiotics with compound probiotics in broilers’ diets.

Abstract

The current study aimed to investigate the effects of a new probiotic compound developed as a potential alternative to synthetic antibiotics for broilers. A total of 360 newly hatched Arbor Acres male chicks were randomly divided into three treatment groups. Each treatment consisted of six replicates with 20 birds in each replicate. The negative control group was fed the basal diet. The positive control group was fed the basal diet supplemented with a commercial antimicrobial, virginiamycin, at 30 mg/kg of basal feed. The compound probiotics group was fed a basal diet containing 4.5 × 10⁶ CFU of Lactobacillus LP184 and 2.4 × 10⁶ CFU of Yeast SC167 per gram of basal feed. The feeding trial lasted for 42 days. The results showed that the compound probiotics were a competent alternative to synthetic antibiotics for improving the growth performance and carcass traits of broilers. The compound probiotics enhanced the immune and antioxidant capacities of the broilers, while antibiotics lacked such merits. The positive effects of compound probiotics could be attributed to an improvement in the intestinal morphology and cecal microbial diversity of broilers, effects which are distinct from those of antibiotics. These findings revealed the differences between probiotics and antibiotics in terms of improving broilers’ performance and enriched the basic knowledge surrounding the intestinal microbial structure of broilers.

Yeast culture improved the growth performance, liver function, intestinal barrier and microbiota of juvenile largemouth bass (Micropterus salmoides) fed high-starch diet

The present study was conducted to investigate the effects of yeast culture on the growth, health and microflora of the juvenile largemouth bass fed high-starch diet. The experiment set three isonitrogenous and isolipidic diets, control (high-starch diet), HSY₁ (high-starch diet with 1% yeast culture) and HSY₃ (high-starch diet with 3% yeast culture). A feeding trial was conducted in largemouth bass juveniles for 8 weeks. The results indicated fish fed with 3% yeast culture not only could improve specific growth rate (SGR), but also significantly decreased hepatic lipid content, hepatic glycogen content, and hepatopancreas somatic index (HSI) compared with the control group (p<0.05). The total superoxide dismutase (T-SOD) and catalase (CAT) activities of HSY₃ group significantly increased while malondialdehyde (MDA) content significantly reduced in liver compared with the control group (p<0.05). Meanwhile, the mRNA expression levels of hepatic Sod and Cat were up-regulated (p<0.05), and liver metabolism showed 111 metabolites were significantly changed in HSY₃ group, liver lipid metabolism pathway remarkably changed. Besides, the intestinal anti-inflammatory cytokines were significantly up-regulated, and the pro-inflammatory cytokines were significantly down-regulated as the inclusion of yeast culture (p<0.05). Notably, HSY₃ group diet up-regulated the expression of Zo-1, Claudin and Occludin in intestine compared with the other groups (p<0.05). Serum d-lactate (D-lac), diamine oxidase (DAO) and lipopolysaccharide (LPS) decreased significantly with the inclusion of yeast culture (p<0.05). Furthermore, the abundance of probiotics (such as Lactobacillus, Bacillus and Bifidobacterium) increased significantly, and the abundance of intestinal potential pathogenic bacteria (Plesiomonas) decreased in HSY₃ group (p<0.05). The phenotypic analysis showed that gram-negative bacteria significantly decreased while gram-positive bacteria increased in HSY₃ group (p<0.05). All in all, this study revealed that supplementation of 3% yeast culture can improve the growth performance and the health of juvenile largemouth bass, and has the potential to be used as an effective synbiotics for M. salmoides.

Qualitative indicators of protein concentrates from pea and chickpea flour

A comparative analysis of the qualitative indicators of food and feed protein concentrates (PC) from pea and chickpea flour was carried out. The chickpea PC contains more protein than the pea PC: 83.22±0.35 and 71.78±0.35% on dry matter (DM), respectively, the biological value adjusted for protein digestibility (PDCAAS) in the pea PC (96%) is higher than that in the chickpea PC (76%). The PCs differed in the content of essential amino acids, copper, cobalt, manganese, nickel, the amount of flavonoids and foaming ability. Higher foaming capacity and lower foam stability in the chickpea PC correlated with higher flavonoid content and percent parallel β-structure and anti-parallel 310-helix proteins. A fodder biomass with a protein content of 61.68-64.10% and a biomass with a cultural liquid with 50.60-53.56% protein on DM were obtained. Biologically valuable concentrates differed in the mass fraction of fat, soluble, insoluble carbohydrates, potassium, magnesium, cobalt, manganese, sodium and the ratio of saturated:unsaturated fatty acids. A correlation was found between the amount of flavonoids, the optical density at D590 nm, and the color of preparations (correlation coefficient R=0.895). It is recommended to use the PCs for food purposes, serum concentrates, in feed for various animals.

Bacillus subtilis DSM29784 Alleviates Negative Effects on Growth Performance in Broilers by Improving the Intestinal Health Under Necrotic Enteritis Challenge

Along with banning antibiotics, necrotic enteritis (NE), especially subclinical enteritis (SNE), poses a significant threat to the chicken industry; however, probiotics are a potentially promising intervention. We aimed to investigate the beneficial effects of Bacillus subtilis DSM29784 (BS) on the treatment of Clostridium perfringens (CP)-induced SNE in broilers. A total of 360 1-day-old broiler chicks were divided into three treatment groups, namely control (Ctr), SNE, and BS treatment (BST) groups, all of which were fed with a basal died for 21days, and then from day 22 onward, only the BST group had a BS supplemented diet (1×10⁹ colony-forming units BS/kg). On day 15, all chicks, except the Ctr group, were challenged with a 20-fold dose coccidiosis vaccine and 1ml CP (2×10⁸) on days 18–21 for SNE induction. Beneficial effects were observed on growth performance in BST compared to SNE broilers. BST treatment alleviated intestinal lesions and increased the villus height/crypt depth ratio. Further, BST broilers showed increased maltase activity in the duodenum compared with SNE chicks, and a significantly decreased caspase-3 protein expression in the jejunum mucosa. Moreover, an increased abundance of Ruminococcaceae and Bifidobacterium beneficial gut bacteria and an altered gut metabolome were observed. Taken together, we demonstrate that the manipulation of microbial gut composition using probiotics may be a promising prevention strategy for SNE by improving the composition and metabolism of the intestinal microbiota, intestinal structure, and reducing inflammation and apoptosis. Hence, BS potentially has active ingredients that may be used as antibiotic substitutes and effectively reduces the economic losses caused by SNE. The findings of this study provide a scientific foundation for BS application in broiler feed in the future.