Inclusion Of Yeast Research Articles

Factors Affecting Yeast Digestibility and Immunostimulation in Aquatic Animals.

The aquafeed industry increasingly relies on using sustainable and appropriate protein sources to ensure the long-term sustainability and financial viability of intensive aquaculture. Yeast has emerged as a viable substitute protein source in the aquaculture sector due to its potential as a nutritional supplement. A substantial body of evidence exists to suggest that yeast has the potential to act as an effective immune-stimulating agent for a range of aquaculture fish species. Furthermore, the incorporation of yeast supplements and feed additives has the potential to bolster disease prevention, development, and production within the aquaculture sector. Except for methionine, lysine, arginine, and phenylalanine, which are typically the limiting essential amino acids in various fish species, the various yeast species exhibit amino acid profiles that are advantageous when compared to fishmeal. The present review considers the potential nutritional suitability of several yeast species for fish, with particular attention to the various applications of yeast in aquaculture nutrition. The findings of this study indicate that the inclusion of yeast in the diet resulted in the most favorable outcomes, with improvements observed in the overall health, growth performance, and nutritional condition of the fish. Digestibility, a key factor in sustainable feed development, is discussed in special detail. Additionally, this review addresses the utilization of yeast as an immunostimulating agent for fish and its digestion in fish. Furthermore, the research emphasizes the necessity of large-scale production of yeast as a substitute for fishmeal in aquaculture.

124 Effects of Saccharomyces cerevisiae and dietary type offered to beef cattle on intake, feeding behavior, nutrient digestibility, and ruminal fermentation

Abstract The effects of live yeast and diet type offered to beef steers on intake, feeding behavior, nutrient digestibility, and ruminal fermentation profile were evaluated. Ruminally cannulated beef steers [n = 8; body weight (BW) = 550 ± 20 kg] were used in a duplicated 4 × 4 Latin square design following a 2 × 2 factorial arrangement of treatments: A) presence of live-yeast [Saccharomyces cerevisiae (CNCM I-1077), at 1 × 1010 CFUּ animal-1ּ d-1]; and B) diet type [steam-flaked corn-based grower or finisher diets (ad libitum intake)]. Live yeast was delivered with gel-capsules (0.25 g, as is) twice daily via ruminal-cannula. Four, 35 d periods were used. Feed refusal was subtracted from offered (dry matter basis) to calculate feed intake (DMI). The 24 h feeding behavior assessment was conducted on d 31 by trained personnel (time spent eating, ruminating, chewing, drinking, resting, and meal size/number). A 5-d fecal collection (twice daily) was used for the digestibility assessment. Ruminal pH was continuously measured (7 d, intra-ruminal Dascor wireless data loggers). Ruminal ammonia-N and volatile fatty acids (VFA) were analyzed at 0, 2, 4, 8, 16, and 23 h on d 35. The GLIMMIX procedure of SAS was used with animals as the experimental unit. No live yeast × diet interactions (P ≥ 0.17) were observed. Intake was not affected (P = 0.83) by live yeast, while steers offered the grower diet consumed more (P ≤ 0.01) NDF, ADF, and hemicellulose compared with the finisher diet. Live yeast increased (P ≤ 0.02) the dietary NDF, ADF, and hemicellulose digestibility of the grower diet by 13.7, 12.8, and 14.6%, and on the finisher diet by 6.7, 9, and 6.4%, respectively. Live yeast did not affect (P ≥ 0.23) major feeding behavior activities measured. Steers offered grower diet spent more time (P ≤ 0.01) on each meal, ruminating, eating, and chewing and less time (P < 0.01) resting. Live yeast did not affect (P ≥ 0.81) ruminal pH variables measured. Steers offered the grower diet had a greater (P < 0.01) ruminal pH pattern compared with the finisher diet. The ruminal ammonia-N and volatile fatty acids were not affected (P ≥ 0.16) by live yeast, while steers offered the finisher diet had a greater (P ≤ 0.01) total VFA and propionate molar proportion, while a lower (P ≤ 0.01) ammonia-N and acetate molar proportion compared with the grower diet. Regardless of the diet type, live yeast improved digestibility of fiber fractions, while dry matter intake was unaffected. Grower diets were more prone to stimulate feeding behavior activities than finisher, while live yeast seemed to not affect such variables. Expected effects of diet type on ruminal fermentation were ratified, while live yeast inclusion did not affect the ruminal fermentation variables evaluated.

Effects of Yeast-Enriched Functionalized Canola Meal Supplementation on Apparent Total Tract Macronutrient Digestibility and Fecal Characteristics, Fecal Microbiota, and Immune Function of Healthy Adult Dogs.

Brewer's dried yeast has a high nutritional value and has long been utilized by the animal feed industry as a source of protein, B-complex vitamins, and minerals. Brewer's dried yeast is also rich in bioactive compounds and may thereby be used as a functional ingredient, providing benefits beyond that of its nutrient content. Canola meal is a high-fiber ingredient that also has unique properties, especially when it is wetted and dried using a proprietary drying system that creates a "functionalized" canola meal. The objective of this experiment was to evaluate the effects of a yeast-enriched functionalized canola meal (FCM) on apparent total tract digestibility (ATTD) and the fecal quality, metabolite concentrations, and microbiota populations, and immune function of healthy adult dogs. Twelve adult female beagles [body weight (BW) = 7.6 ± 0.7kg; age = 5.8 ± 1.3] were used in a replicated 4×4 Latin square design with 28-d periods. Each experimental period consisted of a 22-d adaptation phase, 5 days of total and fresh fecal collection, and blood collection on the last day. To start, all dogs were fed a basal diet to maintain BW for 14 d. Following fecal and blood collections at baseline (-1 d) to confirm health status, experimental periods began testing the following dietary treatments using a Latin square design experiment: 1) FCM only (no yeast inclusion), 2) FCM + low yeast dose, 3) FCM + medium yeast dose, and 4) FCM + high yeast dose. All treatments were top-dressed onto the basal diet at a rate estimated to be 1% of daily intake (as-is basis). Statistical analysis was performed using the PROC MIXED procedure of SAS with the main effect of treatment and the random effect of dog. Significance was declared at P ≤ 0.05, and trends reported if 0.05 < P ≤ 0.10. Supplementation with yeast-enriched FCM had no significant effect on the ATTD of macronutrients or energy or the fecal characteristics, metabolite concentrations, and microbiota populations of dogs. Additionally, no significant differences were observed in circulating immune cell counts or response to Toll-like receptor agonists among treatments. Our results suggest that the yeast-enriched FCM could be included in canine diets without negatively affecting stool quality, fecal metabolite concentrations, or ATTD. Further research is necessary to determine the effective dose of yeast-enriched FCM, potential mechanisms of action, and other potential implications it has on canine health.

Obtention of pelleted Kluyveromyces marxianus CIDCA 9121 with immunomodulatory properties: Selection of protective agents using Plackett–Burman and Box–Behnken experimental designs

Probiotic yeasts are increasingly used in different animal production systems. Supply of feeding in the form of pellets provides productive advantages in several systems such as poultry production or aquaculture. The inclusion of viable yeast in the pellets has to overcome heat stress during palletization and also dehydration stress. We have worked with our previously characterized probiotic strain Kluyveromyces marxianus CIDCA 9121. We evaluated the resistance of this strain to a process dehydration and extrusion after pellet generation, conditions that were not analyzed for this genus of probiotic yeast. We determined the effects of different thermoprotective agents in order to maximize yeast viability over time and preservation of its probiotic traits. To this aim we used the single factor optimization method, Plackett-Burman central compound rotating design (P–B CCRD) and response surface methodology (RSM) for optimize survival conditions in a process performed at laboratory scale. We selected a combination of sucrose, maltose and maltodextrin and we have tested two different combinations of these agents in a pilot plant extrusion/dehydration process showing that one of them could increase yeast viability. Remarkably, we could observe that immunomodulatory capacity of this strain was not affected after dehydration in the presence of the different additives tested and subsequent rehydration, being the first report showing conservation of probiotic traits of K. marxianus strain upon pelleting opening new perspectives for product development.

277 Effect of yeast probiotics in lactation and nursery diets on progeny lifetime growth performance, immune response, and carcass characteristics

Abstract Mixed parity sows (n = 28; Line 241; DNA) and their offspring were used in a farrow-to-finish study to evaluate the effect of live yeast supplementation during lactation with or without yeast extract supplementation during the nursery period on sow and litter performance and lifetime growth performance, antibody titers, and carcass characteristics. Sows were blocked by parity and body weight (BW) on d 110 of gestation and allotted to 1 of 2 dietary treatments with 14 replications per treatment which consisted of a standard corn-soybean meal lactation diet with or without a yeast-based probiotic (0.10% Actisaf Sc 47 HR+; Phileo by Lesaffre, Milwaukee, WI). Following weaning, pigs (n = 350; 241×600, DNA; initial BW = 6.1 ± 0.02 kg) were randomly assigned in a 2 × 2 factorial design within sow treatment to 1 of 2 nursery diets which consisted of a control diet or a diet with pre-probiotic combination (0.10% MS309; Phileo by Lesaffre, Milwaukee, WI) fed for 42 d after weaning followed by common diets until marketing. Two nursery pens were combined in the finisher, such that there were 5 and 10 pigs/pen with 18 and 9 replications/treatment during the nursery and finishing periods, respectively. There were no significant effects of live yeast supplementation on lactation performance (P &amp;gt; 0.079). There was a sow × nursery diet interaction (P = 0.024) during the nursery period where pigs from sows fed Actisaf had increased average daily gain (ADG) when fed control nursery diets compared with pigs from control sows fed control nursery diets (Table). Pigs fed MS309 in the nursery from either sow treatment were intermediate. Pigs from sows fed Actisaf tended to be heavier at marketing (P = 0.067) with heavier hot carcass weight (HCW; P = 0.101), but there were no differences in overall finishing growth performance with the inclusion of yeast in lactation diets or nursery diets (P &amp;gt; 0.10). A subset of pigs were sampled at 7 time points to determine serum porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae antibody sample-to-positive (S/P) ratios and at 5 time points to ascertain percent inhibition of Lawsonia intracellularis. For all 3 immunological criteria, there were no sow diet × nursery diet × day interactions. There was a sow diet × day interaction for PCV2 S/P ratio (P = 0.097) where offspring from Actisaf sows tended to have greater PCV2 S/P ratios at 101 d of age compared with offspring from control sows (P = 0.046). There was a PCV2 S/P ratio nursery diet × day interaction (P = 0.036) where pigs fed MS309 had reduced PCV2 S/P ratios at 66, 78, and 162 d of age (P ≤ 0.022). In conclusion, feeding a pre/probiotic combination in the nursery did not affect performance or immune criteria. Conversely, feeding a live yeast probiotic during lactation resulted in tendencies for increased nursery ADG, final BW, and HCW.

PSII-11 Achieving heavier piglet weights at weaning with live yeast (Saccharomyces cerevisiae) supplementation under field conditions

Abstract The benefits of live yeast supplementation during both gestation and lactation on piglet performance, nutrient digestibility and immune status have been well reported. However, the application of live yeast to gestation diets in some commercial practices may not be warranted. Therefore, the objective of this study was to evaluate the effect of feeding live yeast to lactating sows on piglet performance at weaning under field conditions. Before start of the study, a total of 268 Camborough L42 gestating sows were fed a restricted, commercial diet. From ≈112 d of gestation until weaning, sows were fed a commercial lactation mash diet with or without inclusion of live yeast (Vistacell, AB Vista, UK) at 1 kg/t. Piglets were cross-fostered within treatment to standardize piglet numbers on sows, and weaned at approximately 24 d. Body weights of piglets at weaning were collected from around 40% of sows. Data were statistically analyzed by Mixed Model using JMP Pro v.16.2 software (SAS Institute Inc, Cary, NC), with significance being accepted at P &amp;lt; 0.05. Treatment was included as a fixed factor in all models, with sow ID and piglet ID nested within treatment included as random variables for sow and piglet performance, respectively. The interaction between treatment and parity was also included in the model for sow performance. Sow parities of 4 and above were combined into one group. Proportional piglet body weights were assessed by non-parametric Wilcoxon Test. An interaction between treatment and parity was shown for average daily feed intake (ADFI), whereby parity-1 sows fed the control diet and parities-3 and -4 sows fed live yeast had greater feed intakes than parity-2 sows fed live yeast. Sow body weights and body condition scores at weaning were unaffected by treatment. Piglet body weights at processing, the number of piglets weaned and weaning ages were also unaffected by treatment. However, piglets from sows fed live yeast were significantly heavier (7.12 kg vs. 6.85 kg) at weaning than piglets from sows fed control diets (P &amp;lt; 0.01). In addition, the proportion of piglets at weaning with body weights of less than 7 kg tended to be fewer (45% vs. 55%), with a greater percentage of heavier (&amp;gt;7 kg) piglets, from sows supplemented with live yeast (P = 0.08). In conclusion, these findings indicate that supplementing live yeast solely to the lactating sow can promote growth of nursing piglets leading to improved piglet performance at weaning.

Potential of perennial sorghum for biogas production: Pretreatment with yeast-contained inoculants during anaerobic storage

To investigate the behind mechanism on microbial roles during anaerobic storage of forages for biogas production, inoculants with different ratios of exogenous Lactiplantibacillus plantarum and Saccharomyces cerevisiae were applied during anerobic storage of perennial sorghum. Yeast-contained inoculants increased biogas production of perennial sorghum by 3.81–11.70%. When the proportion of yeast in microbial inoculant increased, the lactic, acetic and butyric acid contents significantly increased (P < 0.01) across the anaerobic storage. Species of Levilactobacillus brevis was the dominant bacteria, while the growth of some pernicious fungi such as Candia and Hannaella were restricted in samples. An equal appliance of lactic acid bacteria and yeast reduced relative abundances of Weissella cibaria and L. plantarum and increased relative abundance of L. brevis of perennial sorghum. In conclusion, the appropriate inclusion of yeasts in the pretreatment process of perennial sorghum can effectively improve the pretreatment efficacy and thus increase the biogas production.

188 Optimal Dose and Functional Properties of Yeast Supplementation in Adult Cats

Abstract Yeast cell wall products have shown different health benefits, such as antioxidant properties, increase of short-chain fatty acids production by intestinal microbes, and immune-stimulatory effects. These benefits are mediated by beta-glucan activity. This study aims to evaluate the optimal level of inclusion of yeast (Saccharomyces cerevisiae) and the longitudinal effects of supplementation for skin and coat quality, and oxidative biomarkers such as malondialdehyde (MDA), superoxide dismutase (SOD), c-reactive protein (CRP), and inflammatory biomarkers from a panel of 19 cytokines and chemokines, as well as the fecal metabolites such as phenol, indole, SCFA, and ammonia of adult cats. The study was a complete randomized design with 40 cats divided into 4 treatments (n = 10/trt). Animals were fed complete and balanced extruded diets with yeast inclusion in different levels formulated for maintenance. The 4 different diets were a control diet (CON) with no yeast inclusion, a low dose yeast diet (400 ppm of beta-glucan; LOW), a medium dose yeast diet (800 ppm of beta-glucan; MED), and a high dose yeast diet (1,600 ppm of beta-glucan; HIGH). Longitudinal analyses were performed every 21 days for a total of 42 days. Cats fed CON treatment had greatest scores (P &amp;lt; 0.05) for hair quality and gloss compared with LOW treatment for main treatment effect. Although no significant differences (P &amp;gt; 0.05) were observed for oxidative stress and inflammatory biomarkers, as well as fecal fermentative-end products. In conclusion, the optimal dose of yeast supplementation showed no detrimental effects on oxidative stress and inflammatory biomarkers, as well as fecal fermentative end products, and had comparable effects on skin and coat quality among the different dosages for adult cats.

The Impact of Distillers Dried Yeast on the Production Performance and Fecal Microbiome of Broiler Chickens

The aim of this research was to assess the influence of partially substituting post-extraction soybean meal with distillers dried yeast on the efficiency of broiler chicken fattening and the intestinal microflora.I Inactive distillers dried yeast Saccharomyces cerevisiae, cultivated on wheat extract, was employed in the study. The research was conducted on 112 Ross 308 line cockerels subjected to a 35-day fattening period, during which they were fed Starter (days 1–10), Grower (days 11–27), and Finisher (days 28–35) diets. Broiler chickens were randomly divided into four groups: control and three experimental groups with varying levels of distillers dried yeast—3%, 6%, and 9%. Cockerels in the control group (Starter diet) exhibited higher feed consumption compared to those receiving 3% yeast in their diet. Cockerels in the group receiving 3% yeast (Grower diet) demonstrated better feed conversion compared to those receiving 9% yeast in their diet. The study revealed that regardless of the broiler chicken fattening period, there was a decrease in the overall number of isolated microorganisms in the feces with an increase in the proportion of distillers dried yeast in the diet. This was confirmed by the total number of bacteria, anaerobic bacteria, Enterobacteriaceae, E. coli, Enterococcus sp., and S. aureus. Based on cluster analysis (dendrogram), it was observed that only a 9% addition of yeast to the diet significantly influenced the quantitative and qualitative composition of the fecal microbiota of broiler chickens. In summary, a properly balanced feed with distillery yeast can be used as a good source of energy and protein in feed mixtures for broilers, serving as a cost-effective alternative to soybean meal. However, for optimal production results and feed costs, the inclusion of yeast in the feed should not exceed 3%.

Live Yeast (Saccharomyces cerevisiae var. boulardii) Supplementation in a European Sea Bass (Dicentrarchus labrax) Diet: Effects on the Growth and Immune Response Parameters.

The present study has been aimed at evaluating the effects of the dietary inclusion of the live yeasts, Saccharomyces cerevisiae var. boulardii (LSB) administered at increasing concentrations (0, 100, and 300 mg kg-1 of feed, here referred to as LSB 0, 100, 300) for 90 days, on the health conditions of European sea bass. The main zootechnical parameters, histological and morphological analyses, innate immunity response parameters (intestinal cytokine expression, lysozyme content, spontaneous hemolytic and hemagglutinating activities, antibacterial activities, and peroxidase activity) were measured as fish welfare parameters. LSB did not impair either growth parameters or the morphometric indexes. LSB down-regulated interleukin-1β transcription in the distal gut of fish treated with 5.4 × 105 CFU g-1 (LSB100) for 21 days. The interleukin-6 mRNA level decreased significantly in the proximal gut for both doses of yeast, after 21 days of feeding; the gene expression of interleukin-6 was significantly lower in the sea bass fed 10.81 × 105 CFU g-1 (LSB300) probiotic. The levels of TNF-α mRNA were not influenced by probiotic supplementation. Increases, although not significant, in the hematological and immunological parameters were also recorded. The data collected in the present study suggests that an LSB-supplemented diet acts on the gut immune system of sea bass by modulating the expression of the key inflammatory genes.

106 Using Postbiotic Saccharomyces Cerevisiae Yeast in Gestation and Lactation Diets of Gilts to Improve Immunoglobulin Transfer and Offspring Growth Pre-Weaning

Abstract Gilts [n = 50; initial body weight (BW) 190.7 ± 4.2 kg] were used to determine the optional inclusion level of postbiotic Saccharomyces cerevisiae in late gestation and lactation diets to improve immunoglobulin transfer and piglet growth performance during the suckling period. Gilts were assigned to one of five (n = 10) diets: standard gestation and lactation diets (Y0) or diets with postbiotic yeast included at either 0.25% (Y0.25), 0.5% (Y0.5), 1.0% (Y1), or 1.2% (Y1.2). Diets were fed from d 85 of gestation until weaning (d 21 after farrowing). During gestation gilts were fed 2.6kg/d and feed was offered ad libitum during lactation. Gilt BW was recorded on d 85 and 110 of gestation, and gilt and piglet BW were recorded on d 1 and 21 of lactation. Twenty-four hours after farrowing, plasma was collected from each gilt and two median BW piglets per litter via orbital sinus. Additionally, 50 mL of colostrum was collected in equal parts from all functional teats on the right side. On d 21, plasma samples were collected from each gilt and two median BW piglets per litter. Concentrations of immunoglobulin (Ig) A, G, and M were quantified in plasma and colostrum. Data were analyzed in SAS with treatment as the main effect. Linear, quadratic, and yeast vs. no yeast contrast statements were used to assess responses to dietary inclusion of yeast. Time (minutes) between farrowing (defined as birth of the first piglet, confirmed by video recording) and sampling was used as a covariate for d 1 Ig concentrations. There were no differences in number of piglets born alive (12.5 ± 0.9), birth weight (1.40 ± 0.45kg), or gilt BW change during lactation (-7.98 ± 6.68kg). Lactation average daily feed intake tended to be 14.6% greater for gilts provided yeast versus no yeast (5.11 vs. 4.46 ± 0.31kg, respectively; P = 0.069). At weaning, offspring from Y0.25 fed gilts had greater BW than piglets from Y0- or Y1.2-fed gilts (6.48 vs. 5.66 and 5.82 kg ± 0.16, respectively; P &amp;lt; 0.001), with all other treatments intermediate. On d 1, colostrum and gilt plasma Ig concentrations were unaffected by diets. However, yeast increased piglet plasma concentrations of IgM (linear; P = 0.034) and tended to increase IgA (linear; P=0.093), and total Ig (linear; P = 0.074). On d 21, gilts fed yeast-containing diets tended to have greater plasma IgA (yeast vs. no yeast and quadratic; P = 0.063 and P = 0.076, respectively), but IgM was greater for gilts fed Y0 (yeast vs. no yeast; P &amp;lt; 0.05). On d 21, piglet plasma IgA tended to be greater when gilts were provided yeast-containing diets (yeast vs. no yeast; P = 0.069). Therefore, postbiotic Saccharomyces cerevisiae was effective in improving maternal transfer, with piglet IgA and IgM concentrations increasing linearly with increasing yeast inclusion, while Y0.25 also improved piglet growth performance during the suckling phase.

279 Maternal Programming of the Piglet Microbiome Through Supplementation with a Yeast Feed Additive

Abstract The objective of this study was to investigate effects of live yeast supplementation of sow diets during late gestation and lactation on sow reproductive performance and piglet microbiome development. Three dietary treatments were imposed on mixed-parity sows (n = 92) from three contemporary farrowing groups during late gestation and lactation. Dietary treatments were based upon the inclusion level (%) of Actisaf Sc47 in corn/soybean meal-based diets: Control (C, 0%), Low (L, 0.1%), and High (H, 0.5%). Sows were fed their assigned gestation diet (1.8 kg ∙animal-1∙day-1/) from days 85 to 110 of gestation. On day 111 of gestation, sows were fed their assigned lactation diet (3.6 kg/head/day) until parturition. Sows were allowed ad libitum access to their assigned lactation diet beginning day one postpartum until piglets were weaned. Fecal and vaginal swabs were collected from all sows on day 85 of gestation (T1-S) and the day before parturition (T2-S). Colostrum and milk samples were collected from 30 focal sows (10/treatment group), and fecal swabs were collected from 6 piglets per focal sow (n = 180) at 24 to 36 hours after birth (T1-P) and weaning (T2-P, ~19 days old). Extracted DNA from swab samples was sequenced on the MiSeq platform targeting the V4 variable region of the 16S rRNA bacterial gene, and sequence data were analyzed using DADA2 plus various packages within the R statistical software. Generalized linear mixed models were built for sow performance data using the R lme4 package, with treatment as a fixed effect, and farrowing group, parity, and sire as random effects. Piglet performance models also included sex as a fixed effect and maternal origin instead of sire as a random effect. No significant differences were observed among dietary treatment groups for gestation or lactation length, lactation feed intake, sow body weights, sow backfat depth, litter size at birth or weaning, pre-weaning piglet mortalities, or piglet growth performance. Although alpha and beta diversity did not differ among maternal dietary treatment groups in sow colostrum, milk, fecal, or vaginal samples (T1-S or T2-S), several taxa were significantly enriched or less abundant in sow samples based upon dietary yeast inclusion levels. Diversity of piglet fecal microbiomes was not different across maternal dietary treatment groups, but community composition was different at both time-points (T1-P: PERMANOVA, R2 = 0.13, P=0.02; T2-P: PERMANOVA, R2 = 0.01, P=0.048). These results indicate that yeast supplementation in sow diets in late gestation and lactation may influence development and composition of piglet gut microbiomes in early life.

Yeast extract improves growth in rainbow trout (Oncorhynchus mykiss) fed a fishmeal-free diet and modulates the hepatic and distal intestine transcriptomic profile

Replacing fishmeal with alternative protein sources and improving new ingredients diets with feed additives are major objectives in aquaculture. The aim of this study was to evaluate benefits for rainbow trout (Oncorhynchus mykiss) of supplementing a fishmeal-free diet, composed of processed animal proteins (dehydrated poultry protein, hydrolyzed feather meal, poultry and pork blood meal), with yeast extract. Juvenile rainbow trout (initial weight 37 ± 2 g) were fed either with a control diet (19% fishmeal) or with a diet based on terrestrial animal by-products (17%) supplemented or not with 3% of yeast extract. Effects of the diets were evaluated in a 4-week digestibility trial and a 12-week growth experiment. Fish health was investigated by measuring plasma immune markers and performing histological study of the gut. Underlying molecular responses were investigated using unbiased transcriptomic analysis of the liver and distal intestine. Results indicated that supplementing with 3% yeast extract did not influence nutrient digestibility substantially. Nevertheless, fish fed the yeast supplemented fishmeal-free diet grew more than those fed the non-supplemented processed animal protein diet (final body weight of 206.7 ± 14.2 g vs 182.3 ± 13.5 g) but less than their counterparts fed the fishmeal diet (230.5 ± 7.6 g). Plasma and structural parameters indicated no exacerbated immune response or signs of intestinal inflammation in fish fed the fishmeal-free diets. However, plasma total immunoglobulin M levels and intestinal villi were significantly higher in fish fed the diet supplemented with yeast extract. The transcriptomic analysis revealed that the diets influenced immune, inflammatory, pathogen fighting and coagulation gene-related expressions. These results suggest that the dietary inclusion of yeast can enhance a fishmeal-free diet by improving rainbow trout performances and potentially their robustness.

The Effects of Brewer’s Spent Yeast (BSY) Inclusion in Dairy Sheep’s Diets on Ruminal Fermentation and Milk Quality Parameters

Brewer’s spent yeast (BSY) is a byproduct of the beer industry, rich in proteins and bioactive compounds. The effects of BSY were investigated through a 6-week feeding trial on 30 lactating dairy Blackhead sheep (54.7 ± 5.66 kg, 177.34 days in milk) distributed under a completely randomised design in two groups: a control group (with soybean meal and sunflower meal as protein sources), and a BSY group, where soybean meal was totally replaced by BSY (5.4% inclusion, DM basis). The inclusion of BSY led to a 25% decrease in ruminal propionate and in the acetate/propionate ratio. BSY influenced the milk fatty acid profile by significantly decreasing the omega 6: omega 3 ratio and increasing the contents of caproic, capric, and lauric acids. Also, the inclusion of BSY was associated with an increase in the milk’s total polyphenols. Consistently, determinations of the parameters of the milk fat’s oxidative stability revealed a decrease in conjugated diene contents. Moreover, the mineral contents of milk were influenced, with an increase in Ca content noted. Overall, these results indicate that BSY represents an alternative feedstuff for ruminants’ nutrition, which could have the potential to induce changes in ruminal fermentation and milk composition that are beneficial for consumers.

Brewer’s Spent Grain with Yeast Amendment Shows Potential for Anaerobic Soil Disinfestation of Weeds and Pythium irregulare

Anaerobic soil disinfestation (ASD) is a promising alternative to chemical fumigation for controlling soilborne plant pathogens and weeds. This study investigated the impact of brewer’s spent grain (BSG), a locally available carbon source, on various weed species and the oomycete pathogen Pythium irregulare in ASD. Two greenhouse studies were conducted using BSG and yeast at full and reduced rates in a completely randomized design with four replicates and two runs per study. In both studies, ASD treatments significantly decreased the seed viability of all weed species and the Pythium irregulare inoculum, while promoting higher cumulative anaerobicity compared to the non-treated control. The addition of yeast had a notable effect when combined with BSG but not with rice bran. When used in reduced carbon rates, yeast supplementation enhanced the efficacy of BSG, providing comparable control to the full rate for most weed species, including redroot pigweed, white clover, and yellow nutsedge. Interestingly, no ASD treatment affected the soil temperature. Furthermore, BSG treatments caused higher concentrations of volatile fatty acids compared to ASD with rice bran and the non-treated control. This finding suggests that the inclusion of yeast in ASD shows potential for reducing the carbon input required for effective soil disinfestation.

Growth performance and haematological indices of broiler finisher chickens fed diets containing Calopogonium mucunoides leaf meal supplemented with yeast

A total of 150 four-week-old Anak finisher broiler chickens were used to determine the growth performance and haematological indices of broiler finisher chickens fed diets containing Calopogonium mucunoides leaf meal supplemented with yeast. They were randomly grouped into 5 treatments with each consisting of 30 broiler chickens. Each treatment group was replicated thrice with equal number of birds (10) per replicate. Five experimental diets were formulated; control diet contained basal diet and soyabean meal which was quantitatively replaced with sun dried Calapogonium mucunoide leaf meal supplemented with yeast at 10, 15, 20 and 25% in other diets. The experiment was laid out in Completely Randomized Design (CRD). The blood of the experimental birds was collected and analysed for packed cell volume (PCV), red blood cell (RBC), white blood cell (WBC), Haemoglobin Concentration (Hb), Mean Cell Haemoglobin (MCH) and Mean Cell Volume (MCV) at the end of 4 weeks. Data obtained were subjected to one way analysis of variance. The results of the study showed that inclusion of yeast significantly (P &lt; 0.05) influenced the feed intake, final liveweight gain, weight gain, feed conversion ratio, red blood cells (RBC) and MCH (Mean Corpuscular Haemoglobin) of the finisher broiler chicken. All parameters tended to improve with increased dietary level of Calopogonium mucunoides leaf meal supplemented with yeast in diets of broiler finisher chickens. Calopogonium mucunoides leaf meal supplemented with yeast did not significantly (P &gt; 0.05) influence PCV (Packed Cell Volume), HBg/dl, WBC (White Blood Cells) and MCHC. It was concluded in this study that Calopogonium mucunoides leaf meal supplemented with yeast could be included at 25% to improve body weight gain, feed conversion ratio and red blood cell of finisher broiler chickens.

Effects of brewer's spent yeast inclusion level and ensiling duration on fermentative, fungal load dynamics, and nutritional characteristics of brewer's spent yeast-based silage

ObjectiveThis study was conducted to evaluate the effect of brewer's spent yeast (BSY) inclusion level and ensiling duration (ED) on fermentative, fungal load dynamics, and nutritional characteristics of brewer's spent-yeast based silage. Materials and methodsTo prepare the silages materials, 4 BSY inclusion levels (0, 10, 20, and 30%) to replace BSG and 3 ED (2,4 and 6 weeks) were arranged in 4 × 3 factorial combination using a completely randomized design (CRD) in 5 replications. The ratio of brewery spent grain (BSG) to wheat bran (WB) used majorly as protein and energy sources, respectively was 30:69 with a 1% salt addition. Parameters measured include observation for surface spoilage, yeast and mold colony count, silage temperature, pH, total dry matter loss (TDML), major proximate, detergent fractions and permanganate lignin, in-vitro organic matter digestibility (IVOMD) and estimated metabolizable energy (EME) values. ResultsThe study revealed that at any BSY inclusion level and ED, extensive mold growths and discolorations were not observed. However, slightly higher values of 6.5, 5.7, and 12.2 colonies forming unit (CFU)/g DM yeast, mold, and total fungal counts (TFC), respectively were recorded only at the 6 weeks of the fermentation period with 30% BSY inclusion level. Brewer's spent yeast inclusion level and ED had a significant (P < 0.05) effect on silage temperature (mean = 18.05 °C) and pH (mean = 4.16). Among proximate and detergent values, crude protein (mean CP g/kg DM = 204.5), neutral detergent fiber (mean NDF g/kg DM = 552.9), and acid detergent fiber (mean ADF g/kg DM = 115.9) responded significantly (P < 0.05) to both BSY inclusion levels and ED. ConclusionAmong nutritional quality, CP, IVOMD, and EME of silage samples were subjected to substantial improvements when silage masses were prepared from 20% BSY inclusion levels and when the same silage materials were allowed to ferment for four weeks. In addition, the lab-based experiment should be supported with additional silage quality parameters like volatile fatty acid content of the silage materials and supplementation of ruminant livestock under both on-station and on-farm conditions using either a pilot and/or target animals.

Experimental investigation on the bond behaviour of steel reinforcement in self-healing concrete

The appearance of cracks in structural reinforced concrete is inevitable and when out of control, it can be the cause of concrete failure. The ingress of water and harmful substances via the cracks is critical as the embedded steel reinforcements in the concrete can be corroded. Crack formation will directly weaken the bond between the reinforcing bar and concrete. To mitigate this issue, cracks should be repaired and closed relatively fast and this can potentially be obtained by incorporating self-healing technologies. Self-healing concrete demonstrates a good healing efficiency by the use of smart materials which allow for autonomous healing or enhance the autogenous healing mechanism of concrete. However, it is questioned whether the precipitates only artificially close the crack or also contribute to improve the bond with the reinforcement. In this study, an experimental investigation was conducted to evaluate the bond properties of self-healing concrete by means of pull-out tests. Four types of healing agents were used including two non-axenic biomass agents (HTN and YEAST) and two commercial agents (crystalline admixture and bacteria (CA and BAC)). The fresh properties and mechanical properties of the concrete including the healing agents were initially investigated. Pull-out tests were executed on uncracked, cracked and healed specimens. Two healing periods (28 and 112 days water immersion) were considered to evaluate the effect of healing time on bond recovery. Test results confirm that the addition of healing agents induced a better improvement of bond properties of steel reinforcement in uncracked concretes with respect to the reference concrete (no healing agent added). The highest bond strength enhancement by 57% on uncracked concrete was obtained with the addition of CA, while the inclusion of other agents such BAC, HTN and YEAST also possessed the bond strength improvement by 47, 21 and 7%, respectively. The presence of a longitudinal crack in concrete significantly reduced the bond strength up to 80% and this effect was not significantly affected by the crack size, when considering cracks in the range of 200─500 µm, and the introduction of healing agents. Nevertheless, the bond properties were slightly recovered after healing due to self-healing effects and formation of healing products in the crack was clearly visible.

Effect of yeast species and processing on intestinal microbiota of Atlantic salmon (Salmo salar) fed soybean meal-based diets in seawater

BackgroundYeasts are gaining attention as alternative ingredients in aquafeeds. However, the impact of yeast inclusion on modulation of intestinal microbiota of fish fed plant-based ingredients is limited. Thus, the present study investigates the effects of yeast and processing on composition, diversity and predicted metabolic capacity of gut microbiota of Atlantic salmon smolt fed soybean meal (SBM)-based diet. Two yeasts, Cyberlindnera jadinii (CJ) and Wickerhamomyces anomalus (WA), were produced in-house and processed by direct heat-inactivation with spray-drying (ICJ and IWA) or autolyzed at 50 °C for 16 h, followed by spray-drying (ACJ and AWA). In a 42-day feeding experiment, fish were fed one of six diets: a fishmeal (FM)-based diet, a challenging diet with 30% SBM and four other diets containing 30% SBM and 10% of each of the four yeast products (i.e., ICJ, ACJ, IWA and AWA). Microbial profiling of digesta samples was conducted using 16S rRNA gene sequencing, and the predicted metabolic capacities of gut microbiota were determined using genome-scale metabolic models.ResultsThe microbial composition and predicted metabolic capacity of gut microbiota differed between fish fed FM diet and those fed SBM diet. The digesta of fish fed SBM diet was dominated by members of lactic acid bacteria, which was similar to microbial composition in the digesta of fish fed the inactivated yeasts (ICJ and IWA diets). Inclusion of autolyzed yeasts (ACJ and AWA diets) reduced the richness and diversity of gut microbiota in fish. The gut microbiota of fish fed ACJ diet was dominated by the genus Pediococcus and showed a predicted increase in mucin O-glycan degradation compared with the other diets. The gut microbiota of fish fed AWA diet was highly dominated by the family Bacillaceae.ConclusionsThe present study showed that dietary inclusion of FM and SBM differentially modulate the composition and predicted metabolic capacity of gut microbiota of fish. The inclusion of inactivated yeasts did not alter the modulation caused by SBM-based diet. Fish fed ACJ diet increased relative abundance of Pediococcus, and mucin O-glycan degradation pathway compared with the other diets.

Diet production and utilization of corn fermented protein compared to traditional yeast in healthy adult cats.

The inclusion of yeast in pet food can provide health benefits and increase palatability. Corn fermented protein is a co-product from ethanol production which contains approximately 20% to 25% yeast. The objective of this study was to determine the effects of the yeast in CFP on diet production and utilization when fed to healthy adult cats. The four experimental diets included a control with 15% soybean meal (CON) and diets containing either 3.5% brewer's dried yeast (BDY), 2.5% brewer's dried yeast plus 17.5% distillers dried grains with solubles (BDY+DDGS), or 17.5% corn fermented protein (CFP). All treatments except CON were formulated to contain 3.5% yeast. Experimental diets were fed to adult cats (n = 11) in an incomplete 4 × 4 replicated Latin square design. Cats were adapted to diet for 9 d followed by a 5-d total fecal collection. Titanium dioxide (0.4%) was added to all diets as an external marker to estimate digestibility. Data were analyzed using a mixed model in SAS (version 9.4, SAS Institute, Inc., Cary, NC) with treatment as a fixed effect and cat and period as random effects. Preconditioner discharge temperature was greater (P < 0.05) for CON and BDY (average, 96 °C) compared to BDY + DDGS and CFP (average, 91 °C). Extruder screw speed, die temperature, kibble toughness, and kibble hardness were greatest (P < 0.05) for CFP. The bulk density of BDY + DDGS at 392 g/L was greater (P < 0.05) than BDY and CFP (average, 342 g/L). The sectional expansion index of kibble for CFP was greater (P < 0.05) than BDY + DDGS and smaller (P < 0.05) than CON but similar to BDY. Fecal output was greatest (P < 0.05) for cats fed BDY + DDGS. Nutrient digestibility was lowest (P < 0.05) for BDY + DDGS. The concentrations of short-chain and branched-chain fatty acids in fecal samples were not altered (P > 0.05) by dietary treatment. Cats had no preference (P > 0.05) when comparing CON to BDY or BDY + DDGS. However, cats consumed significantly less CFP compared to CON. The significant differences for bulk density, fecal output, and nutrient digestibility among dietary treatments are likely due to a greater fiber effect of DDGS compared to CFP. Therefore, the yeast component in CFP may provide greater kibble expansion and nutrient utilization compared to DDGS when fed to cats.