Effects of astaxanthin and esterified glucomannan on hematological and serum parameters, and liver pathological changes in broilers fed aflatoxin-B1-contaminated feed

Effects of non-fasting molting on performance, oxidative stress, intestinal morphology, and liver health of laying hens

Animal welfare concerns in laying-hen production facilities have necessitated research on alternative strategies for improving egg production and hen health. At present, most laying-hen facilities in China use the fasting method, but with international emphasis on animal welfare, scholars have begun to find ways to improve production efficiency while ensuring animal welfare standards are adhered to. Therefore, this study investigated the effects of non-fasting molting on production performance, oxidative stress, intestinal morphology, and liver health of laying hens. A total of 180 healthy 90-week-old Dawu Jinfeng laying hens with similar body weights and laying rates (76 ± 2%) were randomly divided into three groups, with five replicates per group and 12 hens per replicate. The hens in the experimental group (NF) were molted using the non-fasting method, the negative control group (C) was not treated with centralized molting, and the positive control group (F) was molted using the fasting method. The results showed that: (1) During the molting period, the laying rate in the NF group (10.58%) decreased and was significantly lower than that in the other two groups (P < 0.05). During the secondary laying peak period, the laying rate in the NF group was highest (89.71%); significantly higher than that in the C group (P < 0.05). (2) During the molting period, compared to the C group, the NF group showed a significant decrease and increase in the total antioxidant capacity (T-AOC) and superoxide dismutase (T-SOD) activity, respectively (P < 0.05). During the secondary laying peak period, the T-SOD activity of the NF group was significantly lower than that of the C group (P < 0.05). (3) During the molting period, the villus height (VH) and the ratios of VH to crypt depth (V/C) of the duodenum, jejunum, and ileum in the NF group were significantly lower than those in the C group (P < 0.05). At the secondary laying peak period, the jejunum V/C was significantly higher than that in the C group (P < 0.05), whereas in the duodenum and ileum it increased but not significantly (P > 0.05). (4) During the molting period, serum glutathione transaminase (AST) and glutathione alanine transaminase (ALT) activities were significantly higher (P < 0.05), and very low-density lipoprotein (VLDL) content and liver weight were significantly lower (P < 0.05) in the non-fasted and fasted groups. However, there was a low degree of liver injury (cell boundary still visible) in the NF group. At the secondary laying peak period, there was no significant difference (P > 0.05) in the indices among the three groups and the liver returned to normal. In summary, non-fasting molting can improve the production performance of laying hens in the later stages, ensure the welfare and health of animals, and provide a theoretical basis for the efficient production of laying hens.

The Efficacy of Additives for the Mitigation of Aflatoxins in Animal Feed: A Systematic Review and Network Meta-Analysis

The contamination of animal feed with aflatoxins is an ongoing and growing serious issue, particularly for livestock farmers in tropical and subtropical regions. Exposure of animals to an aflatoxin-contaminated diet impairs feed efficiency and increases susceptibility to diseases, resulting in mortality, feed waste, and increased production costs. They can also be excreted in milk and thus pose a significant human health risk. This systematic review and network meta-analysis aim to compare and identify the most effective intervention to alleviate the negative impact of aflatoxins on the important livestock sector, poultry production. Eligible studies on the efficacy of feed additives to mitigate the toxic effect of aflatoxins in poultry were retrieved from different databases. Additives were classified into three categories based on their mode of action and composition: organic binder, inorganic binder, and antioxidant. Moreover, alanine transaminase (ALT), a liver enzyme, was the primary indicator. Supplementing aflatoxin-contaminated feeds with different categories of additives significantly reduces serum ALT levels (p < 0.001) compared with birds fed only a contaminated diet. Inorganic binder (P-score 0.8615) was ranked to be the most efficient in terms of counteracting the toxic effect of aflatoxins, followed by antioxidant (P-score 0.6159) and organic binder (P-score 0.5018). These findings will have significant importance for farmers, veterinarians, and animal nutrition companies when deciding which type of additives to use for mitigating exposure to aflatoxins, thus improving food security and the livelihoods of smallholder farmers in developing countries.

Astaxanthin as a Potential Antioxidant to Improve Health and Production Performance of Broiler Chicken

Recent interest in carotenoids has increased due to their antioxidant and production performance. Astaxanthin (AST) is a xanthophyll carotenoid abundantly distributed in microalgae, which is described as a highly potent antioxidant. Therefore, recent studies have tended to investigate the role of antioxidants in improving metabolic processes and physiological functioning of the body. It is now evident that AST could significantly reduce free radicals and oxidative stress and help to maintain a healthy state. Moreover, AST also could improve the performance of broiler chicken by increasing the daily feed intake, followed by improvement in the food conversion rate.

Effects of Chronic Exposure to Low Levels of Dietary Aflatoxin B1 on Growth Performance, Apparent Total Tract Digestibility and Intestinal Health in Pigs

This study aimed to investigate the effects of chronic exposure to low levels of dietary aflatoxin B1 (AFB1) on growth performance, apparent total tract digestibility and intestinal health in pigs. In a 102-day experiment, fourteen barrows (Duroc×Landrace×Yorkshire, initial BW = 38.21 ± 0.45 kg) were randomly divided into control (CON, basal diet) and AFB1 groups (the basal diet supplemented with 280 μg/kg AFB1). Results revealed that the AFB1 exposure decreased the final BW, ADFI and ADG in pigs (p < 0.10). AFB1 exposure also decreased the apparent total tract digestibility of dry mater and gross energy at 50 to 75 kg and 105 to 135 kg stages, and decreased the apparent total tract digestibility of ether extract at 75 to 105 kg stage (p < 0.05). Meanwhile, AFB1 exposure increased serum diamine oxidase activity and reduced the mRNA abundance of sodium-glucose cotransporter 1, solute carrier family 7 member 1 and zonula occluden-1 in the jejunal mucosa (p < 0.05). Furthermore, AFB1 exposure decreased superoxide dismutase activity (p < 0.05) and increased 8-hydroxy-2'-deoxyguanosine content (p < 0.10) in jejunal mucosa. AFB1 exposure also increased tumor necrosis factor-α, interleukin-1β and transforming growth factor-β mRNA abundance in jejunal mucosa and upregulated Escherichia coli population in colon (p < 0.05). The data indicated that chronic exposure to low levels of dietary AFB1 suppressed growth performance, reduced the apparent total tract digestibility and damaged intestinal barrier integrity in pigs, which could be associated with the decreased intestinal antioxidant capacity and the increased pro-inflammatory cytokine production.

Astaxanthin supplementation enriches productive performance, physiological and immunological responses in laying hens

Objective

Astaxanthin is a natural super antioxidant. The present study was carried out to investigate the effect of astaxanthin rich Phaffia rhodozyma (PR) supplementation in diets on laying production performance, egg quality, antioxidant defenses and immune defenses in laying hens.

Methods

A total of five hundred and twelve 60-week-old Lohmann Brown laying hens (2,243±12 g) were randomly assigned to four groups, each including 4 replicates with 32 birds per replicate. Astaxanthin rich PR was added to corn-soybean meal diets to produce experimental diets containing 0 (Control), 800 mg/kg, 1,200 mg/kg, and 1,600 mg/kg PR, respectively. The astaxanthin content in the diet was 0.96 mg/kg, 1.44 mg/kg and 1.92 mg/kg respectively.

Results

Results showed that dietary PR supplementation tended to increase daily feed intake (p = 0.0512). There was no effect of astaxanthin rich PR on Haugh units, albumen height, egg shape index, eggshell strength, and eggshell thickness at weeks 6 (p>0.05). However, egg yolk color was significantly improved (p<0.05). In addition, astaxanthin rich PR supplementation significantly increased serum glutathione peroxidase and superoxide dismutase activity (p<0.05), increased serum immunoglobulin G content (p<0.05), and reduced malondialdehyde content (p<0.05) in laying hens.

Conclusion

In conclusion, astaxanthin rich PR can improve the color of egg yolk, enhance the antioxidant defenses, and regulate the immune function.

Aflatoxin B1 induces reactive oxygen species-dependent caspase-mediated apoptosis in normal human cells, inhibits Allium cepa root cell division, and triggers inflammatory response in zebrafish larvae

Mycotoxin contamination of food and water is a serious global concern. Aflatoxin B1 (AFB1) is a deadly mycotoxin that contaminates both food and water bodies in the environment. AFB1 is reported to cause severe health issues, including hepatotoxicity, teratogenicity, and immunotoxicity in humans; however, the mechanistic effects on plant and aquatic animals are not fully understood. To obtain a clear understanding of the effects of AFB1 on the ecosystem, we examined the influence of AFB1 exposure on different model systems corresponding to various habitats. In the current study, AFB1 contamination consequences were studied on a human normal cell lines (HaCaT, CCD 841 CoN), meristematic Allium cepa (onion) root cells, and zebrafish embryonic development. Our results clearly indicate that concentrations of AFB1 >10 μM are toxic to HaCaT cells. Morphological changes of HaCaT and CCD 841 CoN cells were clearly observed after exposure to AFB1. Particularly in HaCaT cells, treatment with 50 μM and 100 μM AFB1induces oxidative stress by excessive endogenous free-radical production such as ROS and NO generation. These consequences accelerate the ROS-dependent DNA damage events, which subsequently result in caspase mediated programmed cell death. Exposure of A. cepa root cells to AFB1 for 24 h resulted in abnormal cell division. A. cepa root cells subjected to AFB1 treatment showed a significant concentration-dependent increase in metaphase arrest. Exposure of zebrafish embryos to AFB1 also revealed that AFB1 contamination restricts the larval growth and development, resulting in a remarkably increased zebrafish mortality rate. Collectively, results of the current study indicate that AFB1 contamination triggers the programmed cell death machinery, subsequently affecting the ecosystem.

Astaxanthin Protects OTA-Induced Lung Injury in Mice through the Nrf2/NF-κB Pathway

The aim of this research was to evaluate the potential protective mechanism of astaxanthin (ASTA) against oxidative damage and inflammation caused by ochratoxin (OTA) in mouse lung. We divided mice into a control group (CG), an OTA group (PG), an astaxanthin group (AG), and an OTA+ASTA group (JG). Oxidative indices (malondialdehyde (MDA), total superoxide dismutase (T-SOD), and reduced glutathione (GSH)) and inflammatory markers (interleukin 1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α)) were assayed in the lung, and the lung-weight-to-body-weight ratio was calculated. Apoptosis was detected in pathological sections by the TdT-mediated dUTP nick-end labeling (TUNEL) assay. Oxidative damage and inflammation were detected in the lung of mice after exposure to OTA. Besides, Nrf2- and NF-κB-pathway-associated proteins were detected by Western blot. In contrast with OTA, ASTA significantly raised the expression of Nrf2, HO-1, and MnSOD, while the expression of other proteins (Keap1, TLR4, and NF-κB) was significantly decreased. These results indicate that ASTA exerted protective effects against OTA-induced oxidative damage and inflammation in the lung by regulating the Nrf2 and NF-κB pathways.

The effects of astaxanthin on liver histopathology and expression of superoxide dismutase in rat aflatoxicosis

The metabolism of aflatoxin B1 (AFB1) generates reactive oxygen species (ROS) that destroys hepatocytes. Meanwhile, astaxanthin (AX) is known to have stronger antioxidative activity than other carotenoids. This study aimed to investigate hepatoprotective role of AX from AFB1-induced toxicity in rat by histopathological study and immunohistochemistry of Cu/Zn-SOD (SOD1) which acts as the first enzyme in antioxidative reaction against cell injury from ROS. Twenty Wistar rats were randomly divided into 4 groups. The control and AFB1 groups were gavaged by water for 7 days followed by a single DMSO and 1 mg/kg AFB1, respectively. The AXL+ AFB1 and AXH+ AFB1 groups were given of 5 mg/kg and 100 mg/kg AX for 7 days before 1 mg/kg AFB1 administration. The result showed significantly elevated liver weight per 100 g body weight in AFB1 group. The histopathological finding revealed vacuolar degeneration, necrosis, megalocytosis and binucleation of hepatocytes with bile duct hyperplasia in AFB1 group. The severities of pathological changes were sequentially reduced in AXL+AFB1 and AXH+AFB1 groups. Most rats in AXH+AFB1 group owned hypertrophic hepatocytes and atypical proliferation of cholangiocytes which are adaptive responses to severe hepatocyte damage. The SOD1 expression was also significantly higher in AXH+AFB1 group than solely treated AFB1 and AXL+AFB1 groups. In conclusion, AX alleviated AFB1-induced liver damage in rat by stimulating SOD1 expression and transdifferentiation of cholangiocytes in dose dependent manner.

Astaxanthin protects against early burn-wound progression in rats by attenuating oxidative stress-induced inflammation and mitochondria-related apoptosis

Burn-wound progression can occur in the initial or peri-burn area after a deep burn injury. The stasis zone has a higher risk of deterioration mediated by multiple factors but is also considered salvageable. Astaxanthin (ATX), which is extracted from some marine organisms, is a natural compound with a strong antioxidant effect that has been reported to attenuate organ injuries caused by traumatic injuries. Hence, we investigated the potential effects of ATX on preventing early burn-wound progression. A classic "comb" burn rat model was established in this study for histological and biological assessments, which revealed that ATX, particularly higher doses, alleviated histological deterioration in the stasis zone. Additionally, we observed dose-dependent improvements in oxidative stress and the release of inflammatory mediators after ATX treatment. Furthermore, ATX dose-dependently attenuated burn-induced apoptosis in the wound areas, and this effect was accompanied by increases in Akt and Bad phosphorylation and a downregulation of cytochrome C and caspase expression. In addition, the administration of Ly 294002 further verified the effect of ATX. In summary, we demonstrated that ATX protected against early burn-wound progression in a rat deep-burn model. This protection might be mediated by the attenuation of oxidative stress-induced inflammation and mitochondria-related apoptosis.

Comparison of serum biochemical parameters between two broiler chicken lines divergently selected for abdominal fat content

In humans, obesity is associated with increased or decreased levels of serum biochemical indicators. However, the relationship is not as well understood in chickens. Due to long-term intense selection for fast growth rate, modern broilers have the problem of excessive fat deposition, exhibiting biochemical or metabolic changes. In the current study, the Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF) were used to identify differences in serum biochemical parameters between the 2 lines. A total of 18 serum biochemical indicators were investigated in the 16th, 17th, and 18th generation populations of NEAUHLF, and the genetic parameters of these serum biochemical indicators were estimated. After analyzing the data from these 3 generations together, the results showed that the levels of 16 of the tested serum biochemical parameters were significantly different between the lean and fat birds. In the fat birds, serum concentrations of high-density lipoprotein cholesterol (HDL-C), HDL-C:low-density lipoprotein cholesterol (LDL-C), total bile acid, total protein, albumin, globulin, aspartate transaminase (AST):alanine transaminase (ALT), γ-glutamyl transpeptidase (GGT), uric acid, and creatinine were very significantly higher (P < 0.01), whereas LDL-C, albumin:globulin, glucose, AST, ALT, and free fatty acids concentrations in serum were very significantly lower than those in the lean birds (P < 0.01). Of these 16 serum biochemical parameters, 5 (LDL-C, HDL-C:LDL-C, total bile acid, albumin, and albumin:globulin) had high heritabilities (0.58 ≤ h2 ≤ 0.89), 6 (HDL-C, total protein, globulin, AST:ALT, GGT, and creatinine) had moderate heritabilities (0.29 ≤ h2 ≤ 0.48), and the remaining 5 had low heritabilities (h2 < 0.20). Serum HDL-C, HDL-C:LDL-C, and glucose had higher positive genetic correlation coefficients (rg) with abdominal fat traits (0.30 ≤ rg ≤ 0.80), whereas serum globulin, AST, and uric acid showed higher negative genetic correlations with abdominal fat traits (–0.62 ≤ rg ≤ –0.30). The remaining 10 serum biochemical parameters had lower genetic correlations with abdominal fat traits (–0.30 < rg < 0.30). In conclusion, we identified serum HDL-C and HDL-C:LDL-C levels as potential biomarkers for selection of lean birds. These findings will also be useful in future studies for investigating obesity and lipid metabolism in humans as well as in other animal species.

Aflatoxin B1 impairs mitochondrial functions, activates ROS generation, induces apoptosis and involves Nrf2 signal pathway in primary broiler hepatocytes

Aflatoxin B1 (AFB1) is known as a mycotoxin that causes various health problems in animals, but the precise mechanism of AFB1 on mitochondrial functions and apoptosis in primary broiler hepatocytes (PBHs) is not clear. The objective of this study was to investigate the effects of AFB1 on the mitochondrial functions, reactive oxygen species (ROS) generation, apoptosis and nuclear factor erythroid 2-like factor 2 (Nrf2)-related signal pathway in PBHs. Here, the mitochondrial membrane potential (MMP), ROS generation, antioxidative genes and apoptosis in PBHs induced by AFB1 were investigated. The results showed that AFB1 evoked mitochondrial ROS generation, decreased MMP and induced apoptosis in PBHs. AFB1 increased the percentage of apoptotic cells, and expression of caspase-9 and caspase-3, upregulated messenger RNA (mRNA) expression of Nrf2 and downregulated mRNA expressions of NAD(P)H: quinine oxidoreductase 1, superoxide dismutase and Heme oxygenase 1 in PBHs. The expression of Bax was also observed in cytoplasm. These findings suggested AFB1 results in a significant impairment of mitochondrial functions, activates ROS generation, induces apoptosis, and is involved in Nrf2 signal pathway through mitochondria ROS-dependent signal pathways in PBHs.