Effect of Organic Selenium-Enriched Yeast on Relieving the Deterioration of Layer Performance, Immune Function, and Physiological Indicators Induced by Heat Stress

Exploring the effects of varying levels of selenium-chitosan on production performance, egg quality, and immune health in laying japanese quail

The purpose of this research was to see how different levels of Se-chitosan, a novel organic source of Se, affected the production performance, egg quality, egg Se concentration, microbial population, immunological response, antioxidant status, and yolk fatty acid profile of laying Japanese quail. This experiment used a totally randomized design, with 5 treatments, 6 repeats, and 10 birds in each repetition. The dietary treatment groups were as follows: no Se supplementation (control group), 0.2 mg/kg Na-selenite supplementation, and 0.2, 0.4, and 0.6 mg/kg Se-chitosan supplementation. The feed conversion ratio (FCR) improved linearly in quails fed different levels of Se-chitosan compared to the control group (P < 0.05). Furthermore, Se-chitosan at concentrations of 0.2 and 0.4 mg/kg demonstrated both linear and quadratic increases in albumen height, Haugh unit, and yolk color in fresh eggs compared to the control group. Additionally, Se-chitosan contributed to enhanced shell thickness and strength, along with an increased Se concentration in the yolk. Se-chitosan supplementation at different levels linearly and quadratically reduced coliforms (COL) while increasing lactic acid bacteria (LAB)/coliform ratios (P < 0.05). Se-chitosan supplementation linearly and quadratically increased the total antibody response to sheep red blood cells (SRBC) and IgG titers (P < 0.05). It also linearly decreased the level of malondialdehyde in fresh and stored egg yolks and increased the activity of antioxidant enzymes catalase and glutathione peroxidase linearly, and superoxide dismutase (SOD) both linearly and quadratically in quail blood serum (P < 0.05). Additionally, supplementation of Se-chitosan at levels of 0.2 and 0.6 mg/kg linearly decreased the ∑ n-6 PUFA/∑ n-3 PUFA ratio in the yolk compared to the control group (P < 0.05). It can be concluded that incorporating Se-chitosan as a novel organic source of Se in the diet of laying quails can enhance production performance, egg quality, egg Se concentration, yolk lipid oxidation, microbial population, immune response, antioxidant enzyme activity, and yolk fatty acid profile.

Dynamic responses of systemic immunity and splenic inflammation to long-term cyclic high-temperature exposure in growing pullets and laying hens

Two trials were conducted to draw the phase-response curve of productive and immunological variables in heat-exposed layer chickens at different ages (71 to 130 d, and 211 to 270 d). Birds were acclimated to the following conditions for 60 d: constant optimal ambient temperature at 24°C and high ambient temperature at 34°C for 8 h/d (10:00-18:00). Data collection and biochemical measurements were performed every 10 d. In both age ranges, high temperature favored the innate immunity (P < 0.01) at the cost of performance (P < 0.05) during a given period, including the relative abundance of B and T-helper lymphocytes, lymphocyte proliferation ratio (B and T lymphocytes), and serum immunoglobulin contents (IgG and IgM) in the peripheral blood, as well as splenic expression of inflammation-related genes (iNOS, TLR-4, TNF-α, IL-6, and INF-γ). Compared with laying hens, growing pullets showed a time-delayed activation of immune response following heat challenge, and had no immunosuppression up to the end of exposure. Overall, the immune system of layer birds has a trade-off with production tissues in a hot environment, and exhibits distinct age-range-specific responses of acclimatization.

Climate change and broiler production

Climate change has emerged as a significant occurrence that adversely affects broiler production, especially in tropical climates. Broiler chickens, bred for rapid growth and high meat production, rely heavily on optimal environmental conditions to achieve their genetic potential. However, climate change disrupts these conditions and poses numerous challenges for broiler production. One of the primary impacts of climate change on broiler production is the decreased ability of birds to attain their genetic potential for faster growth. Broilers are bred to possess specific genetic traits that enable them to grow rapidly and efficiently convert feed into meat. However, in tropical climates affected by climate change, the consequent rise in daily temperatures, increased humidity and altered precipitation patterns create an unfavourable environment for broilers. These conditions impede their growth and development, preventing them from reaching their maximum genetic influence, which is crucial for achieving desirable production outcomes. Furthermore, climate change exacerbates the existing challenges faced by broiler production systems. Higher feed costs impact the industry's economic viability and limit the availability of quality nutrition for the birds, further hampering their growth potential. In addition to feed scarcity, climate change also predisposes broiler chickens to thermal stress. This review collates existing information on climate change and its impact on broiler production, including nutrition, immune function, health and disease susceptibility. It also summarizes the challenges of broiler production under hot and humid climate conditions with different approaches to ameliorating the effects of harsh climatic conditions in poultry.

SeMet alleviates LPS-induced eggshell gland necroptosis mediated inflammation by regulating the Keap1/Nrf2/HO-1 pathway

Exposure to lipopolysaccharide (LPS) can lead to inflammation in a variety of tissues and organs. Selenium (Se) plays a crucial role in mitigating inflammatory damage. Compared with inorganic selenium, organic selenium, such as selenomethionine (SeMet), has the advantages of a higher absorption rate and lower toxicity in animals. This study examined the protective effects of SeMet on eggshell gland tissue damage caused by LPS. Hy-Line Brown laying hens were chosen as the experimental animals and were randomly assigned to four groups: control group (C), lipopolysaccharide group (LPS), SeMet group (Se), and SeMet + lipopolysaccharide group (Se + LPS). H&E staining and transmission electron microscope were performed to observe the pathological changes of eggshell glands, oxidative stress related indicators were measured using relevant kits, qRT‒PCR and western blotting were used to evaluate the mRNA and protein levels of the Nrf2 pathway, necroptosis, and inflammation related indicators. The results showed that LPS treatment increased the content of malondialdehyde (MDA), decreased the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX), and decreased the content of glutathione (GSH). LPS increased the levels of Keap1, RIPK1, RIPK3, MLKL, TNF-α, COX-2, and NF-κB, while decreasing the levels of HO-1, NQO1, Nrf2, and Caspase-8. However, SeMet treatment effectively reversed the changes of the above indicators, indicating that SeMet alleviates eggshell gland cell necroptosis-mediated inflammation induced by LPS via regulating the Keap1/Nrf2/HO-1 pathway. This study elucidated the mechanism by which SeMet alleviates LPS-induced eggshell gland tissue damage in Hy-Line Brown laying hens and provided a new direction for expanding the application of SeMet in the feeding and production of laying hens.

Global waterfowl production: stocking rate is a key factor for improving productivity and well-being-a review

Waterfowl is an important animal-protein source, which has the potential to get a bigger share in the animal production sector. However, waterfowl farming practices and welfare standards are not well established yet. Stocking rate is one of the farming standards that can enhance the productivity, behavior, and well-being of birds; however, rare studies are available in this area. Thus, this article (1) gives an overview of the recent global waterfowls' meat and egg production and their population distribution, (2) reviews the effects of stocking rate on social, feeding, and sexual behaviors, (3) shows the effects of stocking rate on growth performance, carcass weight, and meat quality of ducks and geese, and (4) declares the relationship between the stocking rate and egg production. Conclusively, an optimal stocking rate standard can improve behaviors, productivity (meat-egg), and meat quality. Moreover, using weight (kg)/m2 will help in affording the required space allowance for different ducks and geese under various housing systems. The fish-waterfowl production system could be a promising and sustainable solution for increasing waterfowl production, maintaining the welfare of birds, saving energy, and reducing the water footprint of waterfowl meat. Based on prior research findings, we recommended adopting the stocking rate (SR) standard for specific duck and goose breeds to achieve an optimal production-welfare balance.

Detoxification of Selenium Yeast on Mycotoxins and Heavy Metals: a Review

Mycotoxins are secondary metabolites produced by specific fungi. More than 400 different mycotoxins are known in the world, and the concentration of these toxins in food and feed often exceeds the acceptable limit, thus causing serious harm to animals and human body. At the same time, modern industrial agriculture will also bring a lot of environmental pollution in the development process, including the increase of heavy metal content, and often the clinical symptoms of low/medium level chronic heavy metal poisoning are not obvious, thus delaying the best treatment opportunity. However, the traditional ways of detoxification cannot completely eliminate the adverse effects of these toxins on the body, and sometimes bring some side effects, so it is essential to find a new type of safe antidote. Trace element selenium is among the essential mineral nutrient elements of human and animal bodies, which can effectively remove excessive free radicals and reactive oxygen species in the body, and has the effects of antioxidant, resisting stress, and improving body immunity. Selenium is common in nature in inorganic selenium and organic selenium. In previous studies, it was found that the use of inorganic selenium (sodium selenite) can play a certain protective role against mycotoxins and heavy metal poisoning. However, while it plays the role of antioxidant, it will also have adverse effects on the body. Therefore, it was found in the latest study that selenium yeast could not only replace the protective effect of sodium selenite on mycotoxins and heavy metal poisoning, but also improve the immunity of the body. Selenium yeast is an organic selenium source with high activity and low toxicity, which is produced by selenium relying on the cell protein structure of growing yeast. It not only has high absorption rate, but also can be stored in the body after meeting the physiological needs of the body for selenium, so as to avoid selenium deficiency again in the short term. However, few of these studies can clearly reveal the protective mechanism of yeast selenium. In this paper, the detoxification mechanism of selenium yeast on mycotoxins and heavy metal poisoning was reviewed, which provided some theoretical support for further understanding of the biological function of selenium yeast and its replacement for inorganic selenium. The conclusions suggest that selenium yeast can effectively alleviate the oxidative damage by regulating different signaling pathways, improving the activity of antioxidant enzymes, reversing the content of inflammatory factors, regulating the protein expression of apoptosis-related genes, and reducing the accumulation of mycotoxins and heavy metals in the body.

Effect of Dietary Organic Selenium on Growth Performance, Gut Health, and Coccidiosis Response in Broiler Chickens

A total of 252 one-day-old Ross broilers were randomly allocated to one of six treatments in a 2 × 3 factorial arrangement with respective Eimeria challenges (non-infection and infection) and three different selenium (Se) diets. Dietary treatments were as follows: (1) Se un-supplemented control (CON), (2) inorganic Se treatment (SS; 0.3 mg/kg as sodium selenite), and (3) organic Se treatment (SY; 0.3 mg/kg as selenized yeast). Six replicate cages were allocated per treatment. Chickens in the respective Eimeria infection groups were infected with an E. acervulina, E. tenella, and E. maxima oocyst mixture (15,000 oocysts/chicken) on day 16. Growth performance was measured on days 16, 22, and 24. On day 22, intestinal samples were collected from randomly selected chickens to evaluate gut lesion scores, antioxidant enzymes, and tight junction gene expression. Blood, breast, and liver samples were collected to analyze the Se concentrations on day 24. Dietary SY supplementation improved (p < 0.05) the growth performance of the chickens regardless of the Eimeria challenge. Moreover, independent of Eimeria infection, Se supplementation elevated (p < 0.05) the heme oxygenase 1 (HMOX-1) expression in jejunal mucosa at 6 days post-infection (dpi). Duodenal junctional adhesion molecule 2 (JAM-2) expression and jejunal occludin (OCLN) were elevated (p < 0.05) with dietary SY supplementation at 6 dpi. Among Se sources, broiler chickens fed with the SY diet showed higher (p < 0.05) Se concentrations in breast muscle and serum on 8 dpi. These results confirmed the beneficial effects of dietary Se and the efficiency of organic Se compared with inorganic Se for growth improvement and muscle Se enrichment in broiler chickens regardless of coccidiosis infection.

Hypocholesterolemic, Antioxidative, and Anti-Inflammatory Effects of Dietary Spirulina platensisis Supplementation on Laying Hens Exposed to Cyclic Heat Stress

This study aimed to investigate the role of dietary Spirulina platensis (SP) supplementation in relieving the negative impacts of heat stress (HS) on the productive performance, cholesterol profile, redox status, and inflammatory cytokines of laying hens. A total of 288, 45-wk-old and 1550.7 ± 2.3 g initial body weight, HY-Line W-36 laying hens were housed in two environmental-controlled compartments. Layers were allotted to eight treatments of a two × four factorial design, with six replicates containing six birds per treatment. The temperature in one of the compartments was kept at a thermoneutral condition (24 °C group), while the temperature in the other compartment was raised to a cyclic heat stress of 35 °C from 9:00 a.m. to 5.00 p.m. (35 °C group). Layers in each compartment were fed on one of four experimental diets, containing 0%, 3%, 6%, or 9% SP (SP groups). The trial continued for five weeks. As a result of this study, exposure of laying hens to cyclic HS resulted in a significant (p < 0.05) increase in the total cholesterol (CH), low-density lipoprotein-CH, liver- and egg yolk-CH, ceruloplasmin, malondialdehyde, interleukins (IL-1β and IL-6), and tumor necrosis factor-α, and a significant (p < 0.05) decrease in the high-density lipoprotein-CH, total antioxidant capacity, and reduced glutathione levels. HS negatively (p < 0.05) affected the hen−day egg production (EP, 90.5% vs. 77.0%), egg weight (EW, 61.8 g vs. 56.8 g), feed intake (FI, 111.6 g vs. 101.5 g) and feed conversion ratio (FCR, 2.00 vs. 2.37). As SP levels increased in layer diets, a linear (p < 0.05) improvement response in most of the parameters was obtained in both HS and non-HS layers, recording the best results with 9% SP (e.g., 78.8% vs. 87.6% EP, 56.7 g vs. 61.9 g EW, 103.3 g vs. 110.2 g FI, and 2.38 vs. 2.04 FCR, in 0% vs. 9% SP, respectively). When incorporating SP into the diets of HS-layers, the negative impacts of HS were remarkably relieved (p < 0.05). Therefore, diets containing 9% SP could be used as a promising approach to improve the productive and physiological performance of laying hens, particularly under heat stress conditions.