Heat as a stressor of poultry has been studied extensively for many decades; it affects poultry production on a worldwide basis and has significant impact on well-being and production. More recently, the involvement of heat stress in inducing oxidative stress has received much interest. Oxidative stress is defined as the presence of reactive species in excess of the available antioxidant capacity of animal cells. Reactive species can modify several biologically cellular macromolecules and can interfere with cell signaling pathways. Furthermore, during the last decade, there has been an ever-increasing interest in the use of a wide array of natural feed-delivered phytochemicals that have potential antioxidant properties for poultry. In light of this, the current review aims to (1) summarize the mechanisms through which heat stress triggers excessive superoxide radical production in the mitochondrion and progresses into oxidative stress, (2) illustrate that this pathophysiology is dependent on the intensity and duration of heat stress, (3) present different nutritional strategies for mitigation of mitochondrial dysfunction, with particular focus on antioxidant phytochemicals. Oxidative stress that occurs with heat exposure can be manifest in all parts of the body; however, mitochondrial dysfunction underlies oxidative stress. In the initial phase of acute heat stress, mitochondrial substrate oxidation and electron transport chain activity are increased resulting in excessive superoxide production. During the later stage of acute heat stress, down-regulation of avian uncoupling protein worsens the oxidative stress situation causing mitochondrial dysfunction and tissue damage. Typically, antioxidant enzyme activities are upregulated. Chronic heat stress, however, leads to downsizing of mitochondrial metabolic oxidative capacity, up-regulation of avian uncoupling protein, a clear alteration in the pattern of antioxidant enzyme activities, and depletion of antioxidant reserves. Some phytochemicals, such as various types of flavonoids and related compounds, were shown to be beneficial in chronic heat-stressed poultry, but were less or not effective in non-heat-stressed counterparts. This supports the contention that antioxidant phytochemicals have potential under challenging conditions. Though substantial progress has been made in our understanding of the association between heat stress and oxidative stress, the means by which phytochemicals can alleviate oxidative stress have been sparsely explored.

https://biblio.ugent.be/publication/8518014/file/8519404.pdf

Association between heat stress and oxidative stress in poultry; mitochondrial dysfunction and dietary interventions with phytochemicals.

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Association between heat stress and oxidative stress in poultry; mitochondrial dysfunction and dietary interventions with

Review on biological degradation of mycotoxins

Zearalenone as an endocrine disruptor in humans

Mycotoxins, the secondary metabolites of mycotoxigenic fungi, have been found in almost all agricultural commodities worldwide, causing enormous economic losses in livestock production and severe human health problems. Compared to traditional physical adsorption and chemical reactions, interest in biological detoxification methods that are environmentally sound, safe and highly efficient has seen a significant increase in recent years. However, researchers in this field have been facing tremendous unexpected challenges and are eager to find solutions. This review summarizes and assesses the research strategies and methodologies in each phase of the development of microbiological solutions for mycotoxin mitigation. These include screening of functional microbial consortia from natural samples, isolation and identification of single colonies with biotransformation activity, investigation of the physiological characteristics of isolated strains, identification and assessment of the toxicities of biotransformation products, purification of functional enzymes and the application of mycotoxin decontamination to feed/food production. A full understanding and appropriate application of this tool box should be helpful towards the development of novel microbiological solutions on mycotoxin detoxification.

/pdf/strategies-and-methodologies-for-developing-microbial-4zmnpdn6p4.pdf

Strategies and Methodologies for Developing Microbial Detoxification Systems to Mitigate Mycotoxins.

Effects of dietary α-lipoic acid, acetyl-l-carnitine, and sex on antioxidative ability, energy, and lipid metabolism in broilers

The purpose of this research was to investigate the toxicity of zearalenone (ZEA) on the growing performance, genital organs, serum hormones and histopathological changes of pre-pubertal female gilts, and to evaluate the efficacy of Bacillus subtilis ANSB01G in alleviating ZEA toxicosis in gilts. Eighteen pre-pubertal female gilts were randomly allocated to three treatments with one replicate per treatment. The gilts were fed following three diets for 24 days: the Control group was given a basic diet with normal corn; Treatment 1 (T1) was prepared by substituting corn naturally contaminated with ZEA for all normal corn in the basic diet (with a final concentrations of 238.57 μg kg(-1) of ZEA); and Treatment 2 (T2) was prepared by mixing the T1 diet with 2 kg T(-1) of fermented-dried culture of ANSB01G. The results showed that the presence of ZEA in diets significantly increased the vulva size and reproductive organ weight of the T1 gilts as compared with the Control group, and the addition of ANSB01G to diet naturally contaminated with ZEA obviously ameliorated these symptoms, as was observed in the T2 group. The presence of low doses of ZEA in the T1 diet had no significant effect on the level of follicle-stimulating hormone (FSH), luteotrophic hormone (LH) or serum oestradiol (E2) in the serum of gilts, but the prolactin (PRL) level in group T1 increased significantly. The gilts of the T1 group exhibited conspicuous cell enlargement and fatty degeneration of the corpus uteri, swelling, inflammation and lymphocyte infiltration of liver cells as compared with the Control group. The presence of ANSB01G can alleviate these hyperoestrogenic effects caused by ZEA, maintaining the body of gilt in a normal and healthy status. It is suggested that reproductive organs of gilts are seriously affected even if they are fed a low dose of ZEA in less time, and the addition of B. subtilis ANSB01G can effectively alleviate ZEA toxicosis in gilts.

Ameliorative effects of Bacillus subtilis ANSB01G on zearalenone toxicosis in pre-pubertal female gilts

The present study was conducted to determine the effects of L-carnosine (LC) and/or alpha-lipoic acid (ALA) supplementation on growth performance, blood thyroid hormones and lipid profiles in finishing pigs. A total of 40 (Landrace×Yorkshire) pigs with an initial body weight of 57.93±3.14 kg were randomly allocated to 4 experimental diets using a 2×2 factorial arrangement with 2 LC supplemental levels (0 or 0.1%) and 2 ALA supplemental levels (0 or 0.03%) in basal diets. The results showed that pigs fed LC-supplemented diets increased final live weight, average daily gain, and average daily feed intake compared to those of pigs fed without LC-supplemented diets (p 0.05). Additionally, LC supplementation increased serum triiodothyronine, thyroxine levels, and ALA supplementation increased serum triiodothyronine levels (p<0.05). Serum total cholesterol and triglycerides levels were significantly decreased in LC and ALA supplemented groups, respectively (p<0.05). Moreover, serum low density lipoprotein cholesterol levels were lower in the ALA-supplemented groups than those of pigs fed without ALA-supplemented diets (p<0.05). However, no significant LC×ALA interaction effect on growth performance, blood thyroid hormones and lipid profiles was found. This study suggested that dietary supplementation of LC resulted in better growth performance compared to that of ALA supplementation. L-carnosine and/or ALA supplementation positively modified blood lipid profiles, which may have the potential to prevent cardiovascular diseases.

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Effects of Dietary L-carnosine and Alpha-lipoic Acid on Growth Performance, Blood Thyroid Hormones and Lipid Profiles in Finishing Pigs

(1) Background: L-carnosine (β-alanyl-L-histidine), a natural dipeptide, exists at relatively high concentrations in skeletal muscles, and has been shown to protect cells from adverse conditions due to its antioxidant, anti-aging, anti-glycation, and buffering properties. Satellite cells (SCs), residing on the myofiber surface, are crucial for muscle post-growth and regeneration. However, the effects of L-carnosine on muscle development of pigs in vivo, on proliferation and growth of SCs in vitro, and the relationship between SCs and muscle development have not yet been investigated. (2) Methods: The objective of this study was to assess the effect of dietary L-carnosine on growth performance and longissimus dorsi muscle development of pigs in vivo, and to elaborate its molecular mechanisms in vitro using L-carnosine-treated SCs. (3) Results: It was shown that L-carnosine supplementation (0.2 and 2 mM) increased (p < 0.05) SC proliferation and cell percentage in the synthesis (S) phase and decreased cell percentage in the resting (G0)/first gap (G1)/phase. Moreover, average daily gain (ADG) of pigs fed diets containing 0.1% of L-carnosine was higher (p < 0.05) than that of pigs fed diets without L-carnosine, and the longissimus dorsi muscle weight of pigs assigned to the L-carnosine treatments was 7.95% higher compared to control pigs. Both in the longissimus dorsi muscle and cultured SCs of pigs, the Akt/mTOR/S6K signaling pathway was activated (p < 0.05), suggesting that L-carnosine improved muscle growth and SC proliferation of pigs. (4) Conclusions: Considering the important role of SCs in post-natal muscle growth, there is evidence that L-carnosine may improve muscle growth of pigs through promoting SC proliferation via activating the Akt/mTOR/S6K signaling pathway.

/pdf/improved-satellite-cell-proliferation-induced-by-l-carnosine-3rj8anue.pdf

Improved Satellite Cell Proliferation Induced by L-Carnosine Benefits Muscle Growth of Pigs in Part through Activation of the Akt/mTOR/S6K Signaling Pathway

Yinghui Bao

Papers

Effects of dietary α-lipoic acid, acetyl-l-carnitine, and sex on antioxidative ability, energy, and lipid metabolism in broilers

Ameliorative effects of Bacillus subtilis ANSB01G on zearalenone toxicosis in pre-pubertal female gilts

Effects of Dietary L-carnosine and Alpha-lipoic Acid on Growth Performance, Blood Thyroid Hormones and Lipid Profiles in Finishing Pigs

Improved Satellite Cell Proliferation Induced by L-Carnosine Benefits Muscle Growth of Pigs in Part through Activation of the Akt/mTOR/S6K Signaling Pathway