The present study aimed to evaluate the effect of dietary fermented extracts sourced from Saccharomyces cerevisiae (nucleotides, β-glucans and MOS) (Hilyses^®) on the production and health of Nile tilapia (Oreochromis niloticus) broodstock, as well as on seed survival and performance. The trial was performed in a hatchery along the spawning season and continued in the laboratory to monitor the performance in fry and fingerlings. The broodstock were divided into two groups, (C) fed a basal diet and (H) fed 0.4% Hilyses. Blood and histological parameters, antioxidant power, cortisol level and the expression of some immune-related (TLR-2, IL-1β and TNF-α) and growth-related genes (MUC-2 and IGF-1) were measured. The obtained seeds were subdivided into four treatments: (C-C) fed a basal diet, (C-H) fed 0.4% Hilyses, (H-C) fed a basal diet and (H-H) fed 0.4% Hilyses. Results revealed that the dietary inclusion of Hilyses in the broodstock increased seed production, survival, hematological parameters, and antioxidant power. Moreover, it improved the intestinal microstructure and upregulated the immune- and growth-related genes. The growth indices of fry and fingerlings were significantly increased in all Hilyses-treated groups (p < 0.05). The performance in the (H-H) group significantly surpassed those of all groups. Therefore, dietary fermented yeast could be used as a strategic solution to sustain tilapia production.

Functional additives, such as autolyzed yeasts, have been used to achieve greater production efficiency and animal health. These compounds are also alternatives to the use of performance-enhancing antimicrobials. The objective was to evaluate the productive performance, ingestive behavior, apparent digestibility of feed DM and the carcass characteristics of beef steers finished in feedlot receiving autolyzed yeasts in the diet. The experimental design was randomized blocks, consisting of three treatments and six repetitions, where each repetition was represented by a stall with two animals. 36 bulls, ½ Angus × ½ Nelore blood, from the same herd, with an average age of 11 months and an average body weight of ± 330 kg were used.The treatments were as follows: CON - yeast-free diet; Y4 - yeast diet (4 g animal day-1) and Y7 - yeast diet (7 g animal day-1). The product used is a functional ingredient containing the yeast Saccharomyces cerevisiae. The inclusion of autolyzed yeasts resulted in greater daily body weight gain and better feed conversion in the initial feedlot phase. The apparent digestibility of DM of diets containing autolyzed yeast was superior to the control diet, and its use did not interfere with the animal ingestive behavior. Supplementation with autolyzed yeasts at the inclusion level of 4 g day-1 promoted better results in the finishing of feedlot steers, and that the supplemented groups (4 g animal day-1 and 7 g animal day-1) achieved the same degree of carcass finishing, higher than the control group.

Salmonella enteretidis (SE) has a great propensity to translocate from the cecum into internal organs such as the spleen and liver. However, a major concern is the ability of SE to colonize the ovaries. This study aimed to evaluate the efficacy of cell walls from Saccharomyces cerevisiae to control the Salmonella load in the ceca and ovaries of commercial layer pullets. Ten-week-old layer pullets were divided into 2 groups: one group was fed a control diet with commercial feed without additives, and another group was fed the same diet supplemented with 0.5 kg/metric ton of yeast cell walls (YCWs). At 16 wk of age, the birds in both groups were challenged with 3.0 × 10⁹ CFU/mL SE by oral gavage. The birds were euthanized on d 7 and 14 postchallenge to collect the ceca and ovaries for Salmonella load determination. The results demonstrated that there were no statistical differences in ovary SE infection rates. The trend in the prevalence of SE positivity in the ovaries was similar at 14 d, with 2.1% (YCW pullets) to 4.2% positive for the ovaries of the nontreated pullets. There was also no significant difference in the SE log10 MPN/gram between the YCW and the control groups. In the ceca, the high level of SE (3.0 × 10⁹ cfu/pullet), which results in ovarian transmission, causes high intestinal tract inflammation. There was a significant difference in the prevalence of SE in the ceca at 7 d postchallenge but not at 14 d postchallenge. In conclusion, the reduction in Salmonella load observed in the ceca on d 7 in this study shows the potential of YCW supplementation for reducing Salmonella colonization in poultry.

Maintenance may be defined as the state in which the animal can maintain all its vital functions without any loss or gain in body tissue and without...

The effects of graded levels of hydrolyzed yeast (HY) supplementation (0.0, 0.5, 1.0, and 2.0 g/kg, i.e., Control, HY0.5, HY1.0, HY2.0, respectively) on growth performance, gut health, and immune responses of juvenile Nile tilapia ( Oreochromis niloticus ) were assessed in this study. The experiment was conducted in a completely randomized design for 14 weeks, where the treatments were distributed in 16 300‐L tanks with four replicates each. Despite no significant differences, the final body weight and weight gain were numerically higher in treatments containing HY (44.7 and 34.7 g, 43.5 and 33.5 g, and 45.5 and 35.5 g in HY0.5, HY1.0, and HY2.0, respectively). Feed efficiency (FE) was improved linearly ( p < 0.05) with increasing dietary HY level (0.65, 0.70, and 0.72, respectively). Similarly, there was also a significant linear relationship between protein deposition (PD), as well as protein and energy retention efficiency (ERE), with the increasing dietary HY level. Among the blood parameters, only the hematocrit (HCT) value was significantly lower in HY1.0 and HY2.0 compared to the control and HY0.5 treatments. Gut histology showed significantly higher villi length in fish fed HY2.0 diets (795 ± 89.6 µm) compared to those fed the control diet (504 ± 80.7 µm). The average surface volume (SV) of the villi was also higher in tilapia fed HY0.5, HY1.0, and HY2.0 diets (0.025, 0.026, and 0.038 mm ³ , respectively) compared to the control diet (0.021 mm ³ ). All four target genes were significantly upregulated in HY1.0 and HY2.0 treatments. The expression of the genes supporting growth and ATP production, insulin‐like growth factor‐1 (IGF‐1) and glyceraldehyde‐3‐phosphate (G‐3‐P), respectively, was significantly improved, as well as the expression of the immune‐related gene, hepcidin. The expression of ghrelin also showed a significant increase with increasing HY levels. It can be concluded that the HY supplementation improved feed utilization, gut health, nutrient absorption capacity, and immunity in Nile tilapia.