Effects of dietary yeast autolysate (Saccharomyces cerevisiae) on performance, egg traits, egg cholesterol content, egg yolk fatty acid composition and humoral immune response of laying hens

Immunostimulant, hepatoprotective, and nephroprotective potential of Bacillus subtilis (NMCC-path-14) in comparison to dexamethasone in alleviating CFA-induced arthritis

To investigate and compare efficacy as well as safety of Bacillus subtilis and dexamethasone (Dexa) in complete Freund's adjuvant (CFA)-induced arthritis, we used glucocorticoid monotherapy (Dexa 5 mg/kg/day) and B. subtilis (1 × 108 CFU/animal/day p.o) as pre-treatment and concurrent treatment for a duration of 35 days. Specific emphasis was on chronic aspect of this study since long-term use of Dexa is known to produce undesirable side effects. Treatment with Dexa significantly attenuated the arthritic symptoms but produced severe side effects like weight loss, increased mortality, immunosuppression, and altered histology of liver, kidney, and spleen. Oxidative stress was also elevated by Dexa in these organs which contributed to the damage. Treatment with B. subtilis improved symptoms of arthritis without producing any deleterious side effects as seen with Dexa therapy. Immunohistochemistry (IHC) profile revealed decreased expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), interleukin (IL)-1β, tumor necrosis factor alpha (TNF-α), and increased nuclear factor erythroid 2-related factor 2 (Nrf-2) expression by B. subtilis and Dexa treatment in ankle joint of arthritic mice. Radiological scores were also improved by both treatments. This study concludes that B. subtilis could be an effective alternative for treating arthritis than Dexa since it does not produce life-threatening side effects on prolong treatment.

Dietary supplementation with β-mannanase and probiotics as a strategy to improve laying hen performance and egg quality

The objective of this study was to assess the impact of β-mannanase and probiotic on the performance, serum biochemistry, gut morphometric traits, and fresh egg quality of laying hens. A total of 120 cages, housing light-weight laying hens (36 weeks old), were randomly assigned to four different treatments. These treatments included a control group fed non-supplemented diets; diets supplemented with 300 g/ton of beta-mannanase; diets supplemented with 50 g/ton of probiotic; or diets containing both 300 g/ton of β-mannanase and 50 g/ton of probiotics. The trial spanned a duration of 26 weeks and was divided into three productive phases, each lasting 28 days. The inclusion of β-mannanase resulted in a significant improvement in the laying rate by 11% (p < 0.05) compared to the control treatment. Similarly, the addition of probiotics also enhanced the laying rate by 7% (p < 0.05), as well as the supplementation with combined additives (11.5%). Combined additives showed an increase in egg masses, and additive association improved by 13.9% (p < 0.001) in contrast to the control treatment. Overall, β-mannanase and combined additives used during the supplementation period resulted in improvements in the weight of fresh eggs. These benefits were observed after a period of 14 weeks without supplementation (p < 0.05). Furthermore, significant differences were observed in the serum biochemistry and egg masses of birds that were fed diets containing both additives (β-mannanase + probiotics) compared to the control group. Parameters such as uric acid, total cholesterol, and triglycerides displayed notable variations. The villi height: crypt depth showed differences with combined additives (β-mannanase + probiotics). The β-mannanase improved specific gravity, yolk height, length, and pH, and yolk color traits compared to the control treatment. The use of probiotics helped to improve yolk height, pH, and color score. Besides, combined additives (β-mannanase + probiotics) improve yolk height, length, weight, pH, and better traits in yolk color. Hence, incorporating β-mannanase and probiotics into laying hen diets proves to be a highly effective strategy for enhancing laying rate and overall health status, while simultaneously elevating certain quality attributes of fresh eggs.

Effects of live and autolyzed yeast supplementation during transition period on ruminal fermentation, blood attributes, and immune response in dairy cows under heat stress condition

This study was conducted to compare nutrient digestibility, performance and immune response of dairy cows received live and autolyzed yeast during the transition period in high ambient temperature. Cows (n = 25) were randomly divided and received a basal diet with or without live yeast or autolyzed yeast as on top three weeks pre-parturition until three weeks post-parturition. The Control group received a basal diet without yeast products; other groups received 0.5 g live yeast; 1.0 g live yeast; 10 g autolyzed yeast and 20 g/d/head autolyzed yeast. Live yeast resulted in higher nutrient digestibility compared with autolyzed yeast and the control. Methane production was the highest in autolyzed yeast and the lowest in live yeast. Average milk production was the highest in cows that received live yeast. The highest IgG level was for cows that received autolyzed yeast at a dose of 20 g/d/head. Live yeast had no significant effect, but autolyzed yeast increased the relative expression of γ-Interferon and interleukin-2 as compared with the control group. It was concluded that live yeast at a dose of 1.0 g/d/head could influence ruminal fermentation and milk production, but autolyzed yeast at a dose of 20 g/d/head could influence the immune response of dairy cows during the transition period and heat stress.

Effects of enzymatically hydrolyzed yeast supplementation on blood attributes, antioxidant status and gene expression of cytokines in vaccinated dairy cows

This study was done to assess the effects of hydrolyzed yeast on blood cells counts, antioxidant status and gene expression of pro-inflammatory and anti-inflammatory cytokines of vaccinated dairy cows. Twenty Holstein lactating dairy cows were randomly divided into four groups received basal diet without (control) and with 10, 20 and 30 g/d/head of hydrolyzed yeast. Cows were vaccinated against foot and mouth disease virus at day 10 and blood samples were taken 10 days after. Cows received hydrolyzed yeast at doses of 20 and 30 g/d/head had the lowest and those in the control group had the highest malondialdehyde concentration. Cows received hydrolyzed yeast at dose of 20 g/d/head had the highest lymphocyte and the lowest neutrophil/lymphocyte ratio. IL-1β and TNF-α downregulated and INF-γ up-regulated in cows received different doses of hydrolyzed yeast. The lowest expression of IL-1β and TNF-α and the highest expression of INF-γ was for cows received hydrolyzed yeast at dose of 20 g/d/head. The highest titers against foot and mouth disease virus were for cows received hydrolyzed yeast at dose of 20 g/d/head and the lowest titer was for the control group. Supplementation of 20 g/d/head hydrolyzed yeast recommended in vaccinated cows.

The Efficacy of Yeast Supplementation on Monogastric Animal Performance-A Short Review

Due to a continual growth in the world's population and the prohibition of antibiotics in animal production, the livestock industry faces significant challenges in the global demand for meat, eggs, and dairy products. The growing demand for organic products and the prohibition on antibiotic growth promoters (AGPs) have compelled animal nutrition experts to search for natural substitutes that include medical plants and beneficial microorganisms. Natural feed additives like probiotics are found to be more effective than AGPs in reducing the load of harmful intestinal pathogens. One of the probiotics that has generated considerable interest since ancient times is yeast. Yeast is used as a supplement in animal feeds due to its relatively high protein, amino acid, energy, and micronutrient content. Yeast byproducts such as yeast cells and cell walls contain nutraceutical compounds (i.e., β-glucans, mannooligosaccharides, and nucleotides) and have been shown to improve animal growth performance and health. Though the application of yeast supplements has been reviewed to date, only a scarce amount of information exists on the yeast-derived products in non-ruminant nutrition. Additionally, it is difficult for nutritionists to differentiate the characteristics, composition, and optimal feeding among the diverse number of yeast-containing products. Due to the increasing popularity of using yeast-based products in animal feeds, the development of analytical approaches to estimate yeast and its components in these products is greatly needed. Thus, in this review, we intend to provide current knowledge of different categories of commercially available yeast and yeast-derived additives, along with their role in improving animal growth performance and health, their proposed mechanisms of action, and the challenges of quantifying yeast content and biologically active components.

Use of a commercial feed supplement based on yeast products and microalgae with or without nucleotide addition in calves

The use of feed additives with antioxidant and immune response modulatory activity could be a useful strategy in suckling calves to reduce morbidity and mortality. This strategy is based on several feed additives tested for these purposes. The aim of the paper is the examination of a commercial feed additive for adult cows for use in calves, with and without nucleotide supplementation. Seventy-five Holstein Friesian male calves were divided in 3 groups, with each calf randomly assigned to a group according to birth order. All calves received 2 L of pooled colostrum within 2 h of birth. The commercial feed supplement group was orally administered with 5 g/head of Decosel (dried brewer's yeast lysate (Saccharomyces cerevisiae), brewer's yeast walls (Saccharomyces cerevisiae), diatoms, spirulina, barley flour, calcium carbonate; Agroteam srl, Torrimpietra, Italy) and the nucleotides + commercial feed supplement group was orally administered with 5 g/head of an additive containing 2.5 g of Decosel and 2.5 g of nucleotides once daily from birth to 25 d. The control group was orally administered 20 mL of fresh water/head once daily. Calves that received the supplement and the nucleotides showed lower rates of protein and metabolizable energy conversion, with longer villi and greater crypt depth in duodenum. Moreover, the commercial feed supplement alone increased antioxidant capacity [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and ferric-reducing antioxidant power] in plasma some activity of antioxidant liver enzymes, and peripheral blood mononuclear cell viability after in vitro concanavalin A and H₂O₂ stimuli. Dietary supplementation with a commercial feed supplement containing yeast products (yeast cell walls and hydrolyzed yeast) and microalgae enhanced the redox balance and gut morphology in calves, allowing calves to improve their immune response, increasing resistance to stress. Moreover, these beneficial effects were strongly potentiated when dietary nucleotides were added to the supplement.

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.

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.

Role of Yeast and Yeast-Derived Products as Feed Additives in Broiler Nutrition

Antibiotic resistance is looming problem in broiler production globally and there has been an increasing interest to look for sustainable alternatives to antibiotics. Yeast and its derived products are recognized as potential feed additives because of their beneficial impacts on poultry. Particularly, yeast exhibited positive effects on the humoral immunity by increasing serum immunoglobulin (Ig) A levels. Moreover, yeast and its products showed immune adjuvant-like properties that helped the broilers chicken to develop faster and stronger innate immune response under pathogenic challenges. Use of yeast and its products as prebiotic/probiotic improves the gut architecture mainly by improving the gut development and gut microbiome, reduction in colonization of pathogens through competitive exclusion, binding of toxins and enhancing digestion and absorption of nutrients. These unique properties of yeast and yeast products enhance animal welfare and productivity; warrant them to be used as a promising feed additive. This article, therefore, provides insights into the functional role of yeast and its products in the broiler diets and highlights its importance as a commercially viable alternative of synthetic antibiotic growth promoters in the broiler feed industry.

Effect on physiological and production parameters upon supplementation of fermented yeast culture to Nicobari chickens during and post summer

Nicobari is an indigenous bird reared for meat and eggs. This study evaluated the effect of heat stress on plasma levels of leptin, growth hormone and their receptors, liver AMP kinase, plasma cholesterol and lipid peroxide (MDA). The laying period coincided with the post summer period. The birds were equally divided into three groups, control group was offered ad libitum feed and treatment groups were supplemented with fermented yeast culture at 700 mg (T1) and 1.4 g/kg (T2) of feed/day. The levels of plasma Leptin and GH hormones were higher (p < 0.05) in the control group when compared to the treatment groups. The expression of the hormone receptors was higher in the brain, and MMP3 gene expression in the magnum was lower in the treatment group. Plasma cholesterol, MDA and AMP kinase were significantly higher (p < 0.05) in the control group. Fermented yeast culture supplementation decreased feed intake and increased egg production parameters, which indicates a greater efficiency of supplementation. Supplementation reduced the severity of necrosis of villi in the jejunum when compared to control. In conclusion, higher ambient temperature during summer had negative effect on production parameters through modulation of physiological parameters which could be ameliorated by supplementation of FYC.

Bacillus amyloliquefaciens BLCC1-0238 Can Effectively Improve Laying Performance and Egg Quality Via Enhancing Immunity and Regulating Reproductive Hormones of Laying Hens

In this study, we sought to evaluate the effects of dietary Bacillus amyloliquefaciens (B. amyloliquefaciens) BLCC1-0238 supplementation on laying performance, egg quality, antioxidant enzyme activities, reproductive hormone, and immunity of laying hens. A total of 240 Hy-Line Brown laying hens (28 weeks old) were randomly divided into four groups, and three replicates per group (n = 20 per replicate). The control group was fed a standard basal diet, and the three treatment groups were provided the basal diet supplemented with either 0.01%, 0.03%, or 0.06% B. amyloliquefaciens BLCC1-0238 (2 × 10¹⁰ CFU/g), respectively. Hens were allowed 2 weeks to acclimate prior to initiation of the 8-week experiment. It was observed that dietary supplementation with 0.01% or 0.03% B. amyloliquefaciens BLCC1-0238 significantly increased egg production and egg mass. However, no significant differences in feed intake, egg weight, and feed conversion ratio among the four groups were observed. Different levels of B. amyloliquefaciens BLCC1-0238 supplementation also significantly increased egg shell strength and thickness. With respect to the levels of reproductive hormones in the hens, B. amyloliquefaciens BLCC1-0238 supplementation significantly reduced serum adrenal cortical hormone (ACTH) levels, while increasing estradiol (E2) and follicle-stimulating hormone (FSH) secretion in the treatment groups compared to the control group. Relative to the control group, supplementation with 0.03% and 0.06% B. amyloliquefaciens BLCC1-0238 was observed to significantly increase serum glutathione S-transferase (GST) concentration, and supplementation significantly reduced serum IL-1 and IL-6 levels, whereas IL-4 levels increased for all concentrations tested. In conclusion, supplementation of a basal chicken diet with B. amyloliquefaciens BLCC1-0238 can improve laying performance and egg quality through the reduction of stress responses, up-regulation of growth hormones, and supporting immunity in laying hens.

Production performance, egg quality, plasma biochemical constituents and lipid metabolites of aged laying hens supplemented with incomplete degradation products of galactomannan

This study was conducted to investigate the efficacy of incomplete degradation products of galactomannan (IDPG) on the production performance, egg quality, plasma parameters, and lipid metabolites of laying hens. A total of 288 laying hens were allocated into 4 treatments and fed diets supplemented with 0%, 0.01%, 0.025%, and 0.05% IDPG. Results showed that IDPG supplementation significantly increases egg production and decreases feed conversion ratio (P < 0.05). Eggs laid by hens receiving IDPG exhibited higher eggshell strength (P < 0.05). Moreover, IDPG supplementation significantly increased the serum albumin content, and decreased the blood ammonia content as well as triglyceride levels in serum and liver (P < 0.05). Overall, IDPG can be considered as an effective feed additive due to its capacity of improving egg production, increasing plasma protein, and changing lipid metabolism of laying hens.

Effect of Hydrolyzed Yeast Administration on Faecal Microbiota, Haematology, Serum Biochemistry and Cellular Immunity in Healthy Dogs

Fungal microorganisms are regularly found in the gastrointestinal tract of healthy and diseased dogs especially from the phyla Ascomycota and Basidiomycota; however, it is necessary to better understand their role in host health. One of the most commonly studied yeast species in humans or animals is Saccharomyces cerevisiae especially in its live cell form. Scarce knowledge on its hydrolysate product effects in dogs forced us to test diet supplemented with hydrolyzed brewery S. cerevisiae (at a dose 0.3% of the diet) for 14 days to healthy adult dogs. Twenty German Shepherds were randomly divided into 2 groups: control and experimental, ten dogs in each. The experiment lasted 42 days (blood and faeces sample collection at days 0, 14, 28 and 42). The results of this straighforward experiment showed significant increase in the abundance of bifidobacteria (day 14), lactic acid bacteria (day 42) and clostridia (day 42). The faecal pH was significantly increased at day 28. In blood serum, the concentration of triglyceride and cholesterol decreased (day 42) while activities of alanine aminotransferase (at day 14) and aspartate aminotransferase significantly increased (at days 28 and 42). Activities of these enzymes were above reference range top in 7 dogs (ALT) and 4 dogs (AST). Haematological paramaters and activity of phagocytes as well as on percentage of lymphocyte subsets CD4⁺, CD8⁺, CD4⁺CD8⁺ and CD21⁺ were not changed during the experiment. The important point of these results is their onset mostly in the post-supplementation period. The observation of some unexpected effects emphasizes the need for reassessment to use yeasts products for dogs but further studies using different doses are necessary.

Prospects of yeast based feed additives in poultry nutrition: Potential effects and applications

Yeast and its derivatives are extensively utilized as feed additives in poultry industry owing to their desirable health and growth promoting effects. Exhaustive number of studies had reported positive effects of yeast based additives on growth, meat quality, immunity, antioxidant status, and gastrointestinal functions in poultry birds. Owing to their prebiotic/probiotic properties, they also play significant role in gut development and modulation of gut microbiome by favouring beneficial microbes while reducing colonization of pathogenic microbes by competitive exclusion. They also possess effective potential for binding of dietary toxins in addition to improving digestion and utilization of nutrients. Moreover, yeast based additives have exhibited desirable effects on humoral immunity by increasing serum immunoglobulin (Ig) A levels. These additives have been also used as immune adjuvants to boost innate immune response under any pathogenic challenges in birds. Due to their diverse biological activities, yeast products are potentially capable for immune hemostasis by mediating balance between pro- and anti-inflammatory activities. These unique properties of yeast based products make them promising feed additive to promote health and productivity leading to efficient poultry production. Yeast can be supplemented in poultry diets @ 5.0–10.0 g/kg of feed. Numerous studies had reported significant improvement in body weight gain (3 to 8%) and FCR (1.6 to 12%) in broilers in response to supplementation of yeast based additives. Moreover, yeast supplementation also improved hemoglobin (Hb g/dl) levels up to 2.59 to 6.62%, total protein (>0.69%) while reducing serum cholesterol (mg/dl) up to 3.68 to 13.38%. Despite the potential properties and beneficial effects, use of yeast and its derivatives as feed additives in poultry industry is not matching its inherent potential due to many reasons. This review aims to highlight the importance and potential role of yeast and its products as natural growth promoter to replace in feed antibiotics to address the issues of antibiotic residues and microbial resistance. This article provides insights on functional role of yeast based additives in poultry diets and their importance as commercially viable alternatives of antibiotic growth promoters in poultry feed industry.

Effect of Trichoderma reesei Degraded Date Pits on Antioxidant Enzyme Activities and Biochemical Responses of Broiler Chickens

The long-term use of antimicrobials as growth promoters in poultry feed leads to antimicrobial resistance in pathogens. Thus, alternatives to antibiotics are essential for reasons associated with both safety and cost-effectiveness. Underutilized plant sources need to be developed to replace antibiotics in broiler feed. Several feed resources have been introduced so far, but they have yet to be applied widely. Date pits are a major by-product of the date industry (6–8%) and have the potential antioxidant to replace antibiotics. In this study, fresh date pits were degraded using the mold Trichoderma reesei under solid-state degradation (SSD), resulting in degraded date pits (DDP). A total of 180 Brazilian “Cobb 500” broiler chicks were divided into six feed treatments in triplicate groups. The treatments were corn-soy basal diet (positive control; C+), corn-soy + 20% oxytetracycline at 0.05% (negative control; C–), corn-soy + 10% DDP, corn-soy + 0.2% mannan-oligosaccharides (MOS), corn-soy + 0.1% mannose, and corn-soy + 0.2% mannose. The antioxidant and biochemical effects of DDP, MOS, and mannose were determined in the blood serum, liver, and intestine of broilers at age 21 and 42 days. The results indicated that the contents of antioxidants such as flavonoids and phenolics, as well as the MOS content in DDP, were increased by the degradation process. Additionally, mannose, glucose, arabinose, rhamnose, and glucuronic acid were significantly increased in DDP after degradation. The activity of antioxidant enzymes (GPx—glutathione peroxidase, catalase, and SOD—superoxide dismutase) in the serum, liver, and intestine of broilers fed with diets containing 10% DDP and 0.2% MOS was increased significantly compared to the control group. Malondialdehyde activity was decreased, whereas the mean corpuscular hemoglobin level and the iron content were significantly upregulated in the broilers fed with 10% DDP, 0.1% mannose, and 0.2% MOS diets compared with the control. Thus, DDP can be used to improve the antioxidant status and has a prebiotic-like effect in broiler chicken performance.

Auto-lysed yeast and yeast extract effects on dry matter intake, blood cells counts, IgG titer and gene expression of IL-2 in lactating dairy cows under heat stress

The objective of this study was to assess the effects of auto-lysed yeast and yeast extract on performance and immune responses of cows in hot climate in the early lactation period. Twenty five lactating dairy cows randomly assigned to 5 groups and 5 replicates. Cows received basal diet with or without auto-lysed yeast (20 or 40 g/d/head) or yeast extract (20 or 40 g/d/head) as on top-dressed. There were no differences for daily dry matter intake, milk production milk fat and the counts of red blood cells and white blood cells among treatments (p > 0.05). There were significant differences among treatments for immunoglobulin G (IgG) level, lymphocyte and neutrophil percentages. Yeast extract had no effect on IgG level, but auto-lysed yeast increased IgG level and neutrophil percentage and decreased lymphocyte percentage (p < 0.05). The highest relative interleukin-2 gene expression was for cows received auto-lysed yeast at the level of 40 g/d/head. Yeast extract had no significant effect on interleukin-2 gene expression as compared to the control group. It was concluded that auto-lysed yeast at the level of 40 g/d/head had no effect on performance, but it could positively influence on immune response of lactating dairy cows in hot climate during early period of lactation.

Yeast culture promotes the production of aged laying hens by improving intestinal digestive enzyme activities and the intestinal health status

Yeast culture (YC) positively affects the performance of laying hens. The purpose of the present study was to explore the underlying mechanism for the YC-mediated performance improvement. Sixty 67-week-old Hy-Line Brown laying hens were randomly allocated into 2 experimental groups with 5 replicates of 6 birds each. One group was fed a control diet, whereas the other received the control diet supplemented with YC at 3.0 g/kg; treatment lasted for 8 wk. The results showed that dietary YC supplementation increased (P < 0.05) the total egg weight (11.2–13.6%) and egg-laying rate (13.0–13.5%) but decreased (P < 0.05) the feed/egg ratio by 9.3 to 11.0% during weeks 5 to 6 and 7 to 8 compared with the control. However, egg quality, including eggshell strength, eggshell thickness, egg weight, albumen height, egg yolk color, and Haugh unit, was not affected (P > 0.05) by YC supplementation. Furthermore, dietary YC supplementation increased (P < 0.05) chymotrypsin and ɑ-amylase activities by 54.8 to 62.5% in the duodenal chyme and reduced (P < 0.05) plasma endotoxin by 44.1%. YC dietary supplementation also upregulated (P < 0.05) the mRNA levels of intestinal barrier–related genes (occludin and claudin 1) and antimicrobial peptides genes (β-defensin 1 and 7 and cathelicidin 1 and 3) in the duodenum or jejunum compared with the control. In conclusion, dietary YC supplementation improved the performance of aged laying hens, potentially through the upregulation of intestinal digestive enzyme activities and intestinal health-related gene expression.

Regulation of hyperglycemia in diabetic mice by autolysates from β-mannanase-treated brewer's yeast

BACKGROUND

Diabetes mellitus is a serious chronic disease, characterized by hyperglycemia. This study administered either β-mannanase-treated yeast cell autolysis supernatant (YCS) or yeast cell-wall residues after autolysis (YCR) to investigate their influence on the alleviation of diabetes in a diabetic mouse model.

RESULTS

Application of either YCS or YCR led to body weight gain, blood glucose reduction, and an improvement in lipid composition in the diabetic mice. Administration of YCS was more effective in inhibiting oxidative stress than YCR. The expression of PPARα and CPT1α was enhanced, improving lipid biosynthesis, and Trx1 and HIF-1-α genes were downregulated due to the activation of thioredoxin following the interventions, indicating that the processes of lipid metabolism and oxidative stress were heavily involved in the reduction of diabetic characteristics following the interventions. The current study revealed that consumption of YCR also led to a reduction in hyperglycemia, this being associated with its richness in mineral elements, such as chromium and selenium.

CONCLUSION

This study may highlight the potential of both YCS and YCR as functional ingredients in dietary formula for improving diabetic syndromes. © 2019 Society of Chemical Industry.

Influence of Pichia pastoris X-33 produced in industrial residues on productive performance, egg quality, immunity, and intestinal morphometry in quails

This study was conducted in quails to evaluate the probiotic potential of Pichia pastoris X-33, cultivated in parboiled rice effluent supplemented with biodiesel glycerol or in standard medium Yeast Extract–Peptone–Dextrose (YPD). Forty-days-old female quails were divided into three treatments: T1 (Control) received a basal diet without P. pastoris; T2 (Pichia Effluent) received a basal diet supplemented with P. pastoris grown in parboiled rice effluent and biodiesel glycerol, and T3 (Pichia YPD) received a basal diet supplemented with P. pastoris produced in YPD. The birds were vaccinated against Newcastle Disease (NDV), Avian Infectious Bronchitis (IBV), and Gumboro Disease on days 1 and 28. The following parameters were analyzed: performance, egg quality, humoral immune response to the vaccines, organ weight, and intestinal morphometry. P. pastoris grown in YPD increased egg weight (p < 0.05). The lowest liver weight on day 14 was obtained in Pichia Effluent, whereas both P. pastoris supplemented groups had the lowest duodenum weights on day 14. Besides that, livers and duodenums presented no morphological changes in any of the three treatments. Supplementation of P. pastoris modulated the immune system of the birds, increasing anti-IBV, anti-NDV, and anti-Gumboro antibodies levels compared to the Control (p < 0.05). In conclusion, quail’s immune response was improved by Pichia pastoris X-33, either it was grown in YPD or industrial residues, and the egg weight increased with Pichia pastoris X-33 grown in YPD, thereby demonstrating to be a promising probiotic for poultry.

Intestinal mucosa develops in a sex-dependent manner in Japanese quail (Coturnix japonica) fed Saccharomyces cerevisiae

1. The aim of study was to investigate whether the impact of the yeast Saccharomyces cerevisiae on the histological structure of the intestine, innervation of the small intestine wall, and basal biochemical serum parameters in Japanese quail was sex dependent. 2. One-day-old healthy male and female Japanese quail were fed either a basal diet containing no yeast (control group) or the basal diet plus 1.5% (15 g/kg of diet) of yeast (S. cerevisiae inactivated by drying). Samples from the duodenum and jejunum were taken from each bird at the age of 42 days. Blood samples were collected at this age and the concentrations of glucose, total protein, creatinine, uric acid, lipid profile (total cholesterol, low density lipoproteins (LDL), high density lipoproteins (HDL) and triacylglycerols (TG)), alanine aminotransferase (ALAT), aspartate aminotransferase (AspAT), lactate dehydrogenase (LDH), amylase (AMY), calcium, phosphorus and iron were determined. 3. Female quail fed diets supplemented with yeast had significantly lower total cholesterol and amylase activity than the control females. The concentration of HDL was higher in the male quail than in the females, irrespective of the treatment. An opposite effect was observed in LDL. The diet treatments influenced the activity of AspAT, which was significantly less in the male quail fed diets with 1.5% yeast. 4. Supplementation with S. cerevisiae increased the myenteron, submucosa and mucosa thickness, villus length and thickness and size of absorptive surface, while the number of villi and enterocytes were decreased in the duodenum in males. Female quail showed an increased absorptive surface in the jejunum. The Meissner (submucosal) plexuses were influenced by the feeding and sex to a greater extent than the Auerbach plexus (in the muscularis propria). 5. The results demonstrated that S. cerevisiae (1.5%) in the diet caused significant positive effects in Japanese quail, exerting an effect on the morphology of the small intestine in a sex-dependent manner.

Bacillus Probiotic Supplementations Improve Laying Performance, Egg Quality, Hatching of Laying Hens, and Sperm Quality of Roosters

The study aims at elucidating the effect of bacilli probiotic preparations on the physiology of laying hens and roosters. Probiotic formulations were prepared as soybean products fermented by Bacillus subtilis KATMIRA1933 and Bacillus amyloliquefaciens B-1895. In this study, groups of male and female chickens were used. These groups received a probiotic preparation based on either B. subtilis KATMIRA1933 or B. amyloliquefaciens B-1895, or of a mixture of strains, from the first day to the age of 39 weeks. These preparations positively affected egg production, quality of sperm production, and quality and hatchery of eggs. Considering the simplicity and cost effectiveness of the soy-based probiotic preparation, these formulations should be considered as advantageous in modern livestock production.

Effects of dietary Lactobacillus acidophilus and Bacillus subtilis on laying performance, egg quality, blood biochemistry and immune response of organic laying hens

The objective of this study was to evaluate the effects of two different probiotic micro-organisms on the performance, egg quality and blood parameters of organically reared hens. A total of 900 16-week-old Hy-Line layer hybrids were randomly assigned to three groups of 300 birds each. The control (CTR) group was fed a corn-soya bean cake-based diet; the L group was fed the same diet supplemented with 0.1% Lactobacillus acidophilus, while the B group was fed the same diet supplemented with 0.05% Bacillus subtilis. Data were recorded at the beginning (weeks 5 and 6: T1) and at the end (weeks 19 and 20: T2) of the experiment, and no differences in hen performance were recorded between dietary groups or sampling times. All of the investigated clinical chemistry parameters, except GGT, were affected by diet (p < 0.05), with the best results recorded for the probiotic-treated groups. The immune-response values showed higher blood bactericidal activity in the B and L groups at T2 (p < 0.05) and a lower lysozime concentration in the B group at T1. Higher antibody production against Newcastle disease virus was observed in the L group compared to the CTR (p = 0.013). No differences in oxidative status were recorded, and no effects of diet on egg quality were observed. Among the physical egg characteristics, only the Roche scale colour was affected by diet (p < 0.05): the egg yolk was paler in the L group. The age of the hen was the most relevant factor affecting physical egg characteristics. The chemical parameters of the egg were almost unaffected by supplementation with probiotics except for the lipid content, which decreased with the L diet (p < 0.05). Both probiotic inclusions had beneficial effects on hen metabolism and welfare, and L. acidophilus induced the best immune response.

Influence of dietary inclusion of Bacillus licheniformis on laying performance, egg quality, antioxidant enzyme activities, and intestinal barrier function of laying hens

This experiment was conducted to evaluate the effects of dietary inclusion of Bacillus licheniformis on laying performance, egg quality, antioxidant enzyme activities, and intestinal barrier function of laying hens. Hy-Line Variety W-36 hens (n = 540; 28 wk of age) were randomized into 6 groups, each group with 6 replications (n = 15). The control group received the basal diet formulated with maize and soybean meal. The treatment groups received the same basal diets supplemented with 0.01, 0.02, 0.03, 0.06, and 0.09% Bacillus licheniformis powder (2 × 10(10) cfu/g) for an 8-wk trial. The results showed that dietary supplementation with 0.01 and 0.03% B. licheniformis significantly increased egg production and egg mass. However, no significant differences were observed in egg weight, feed consumption, and feed conversion efficiency among the 6 groups. Supplementation with different levels of B. licheniformis was found to be effective in improvement of egg quality by increasing egg shell thickness and strength. Compared with control, d-lactate content, diamine oxidase activity, and adrenocorticotropic hormone level in serum decreased significantly, and the level of estradiol and follicle-stimulating hormone increased significantly in plasma of all the experimental groups. Dietary supplementation with B. licheniformis increased the intestinal villus height and reduced the crypt depth. In conclusion, dietary inclusion of B. licheniformis could improve laying performance and egg quality significantly in a dose-dependent manner by decreasing the stress response, upregulating the growth hormone, and improving intestinal health.

Effect of iodine-enriched yeast supplementation of diet on performance of laying hens, egg traits, and egg iodine content

The aim of the study was to evaluate the effect of iodine yeast (I-yeast) supplementation on the performance, egg traits, and iodine content of eggs of laying hens. The experiment was conducted as a completely randomized design. A total of 60 laying hens (Hy-Line Brown), 25 wk of age, was divided into 3 groups (4 replicates), and a feeding experiment was conducted for 12 wk. The concentrations and forms of iodine added to the basal diet were as follows: control group, 1 mg of iodine/kg of feed, Ca(IO(3))(2)•H(2)O; experimental groups E1 and E2, 1 and 2 mg of iodine per kilogram of feed, I-yeast, respectively. The iodine yeast did not significantly affect BW gain. Lower level of hen day egg production for groups E1 and E2 was not confirmed statistically; however, it was probably the consequence of low replication. Feed intake was the lowest in the E1 group and feed conversion rate was the highest in the E2 group. Furthermore, the egg and albumen weight was the highest in the group supplemented with 2 mg/kg of iodine from I-yeast (P < 0.05). The concentration of iodine in the egg yolk from groups E1 and E2 was respectively about 80 and 90% higher, compared with the control group. Eggshells from the group fed with 2 mg/kg of I-yeast contained almost 3 times more iodine than eggshells from the control group. The results suggest that iodine yeast supplementation in the diet of laying hens is an effective method for increasing iodine concentration in eggs and thus could contribute to elimination of iodine deficiency disorders in humans consuming iodine-enriched eggs.