Heat-induced protein oxidation of soybean meal impairs growth performance and antioxidant status of broilers

The beneficial impacts of nano-propolis liposomes as an anti-stressor agent on broiler chickens kept under cyclic heat stress

This research assessed the impacts of dietary nano-propolis liposomes (NPRL) inclusion on the growth, blood biochemical components, immune function, and oxidative status of broilers exposed to cyclic heat stress (HS). Birds were fed with a basal diet supplemented with various levels of NPRL at 0 (HS), 100 (NPRL100), 250 (NPRL250) and 400 (NPRL400) mg/kg diets. Diets supplemented with NPRL significantly improved the growth indices and feed utilization, hemoglobin and red blood cells (P < 0.01). White blood cells, lymphocytes and monocytes were significantly decreased by NPRL inclusion (P < 0.001). Dietary supplementation of 250 or 400 mg of NPRL /kg reduced the pathogenic bacteria counts (Salmonella, E. coli and Enterococci) (P < 0.01). The birds fed diets with NPRL (400 mg/kg diet) significantly downregulated the mRNA IFNγ gene (p < 0.001), while both groups (NPRL100 and NPRL250) had similar results (P > 0.05). The iNOS gene was significantly decreased by the dietary NPRL inclusion in a dose-dependent manner. Birds in NRPL groups had inferior levels of the mRNA of interleukin-4 and tumor necrosis factor genes. The lysosome activity was significantly reduced by dietary 250 or 400 mg of NPRL inclusion (P < 0.001). Birds in NPRL250 and NPRL100 had greater IgG (P < 0.05) than the other groups. Regarding oxidative-related biomarkers, dietary NPRL inclusion decreased myeloperoxidase and malondialdehyde levels significantly compared to those with the HS group (P < 0.001). Broilers in the NPRL400 group had the lowest levels of total bilirubin and gamma-glutamyl transferase. NPRL250 had the lowest values of urea compared with other groups (P < 0.001). Dietary NPRL inclusion improved the broiler's hepatic and intestinal architecture exposed to cyclic heat stress. These results indicate that employing NPRL in the diets of stressed broilers can enhance heat resistance by enhancing blood metabolites and immunity, reducing inflammation and oxidative stress.

Effects of expeller soybean on growth performance, amino acid digestibility and intestinal integrity

Expeller soybean (ESB) is a widely used protein source in broiler diets due to its high amino acid digestibility. However, improper heat processing of ESB can negatively affect nutrient digestion, absorption, and metabolism leading to decreased growth performance. The study aimed to investigate the impact of varying processing temperatures on growth performance, amino acid digestibility (AID), and intestinal integrity using 3 different commercial batches of ESB processed at distinct temperatures. These temperatures were 182°C (normal-control), 199°C (overcooked), and 154°C (undercooked). 1,860 off-sex male Cobb 500 broilers were allocated randomly to these treatments, with 10 replicate floor pens (62 birds/pen) from 1 to 35 d of age. Birds consuming the overcooked ESB exhibited significantly lower body weight gain (BWG) and feed intake (FI) on d 14, 28, and 35. They also showed higher feed conversion ratio (FCR) and smaller relative right pectoralis major (RPM) weights at d 35. Meanwhile, birds fed undercooked ESB demonstrated reduced BWG at d 14. Serum fluorescein isothiocyanate-dextran (FITC-d; 4 kD) concentrations on d 16 were notably elevated in birds fed overcooked ESB, indicating increased gut permeability. Overcooked ESB reduced the AID coefficients of several amino acids on d 14 and 28, with Lys experiencing the highest reduction (8%). Undercooked ESB, however, mainly affected the AID of Val, and Phe at d 28. In conclusion, overcooked ESB decreased amino acid digestibility, impaired gut barrier function, and led to diminished growth performance. Conversely, undercooked ESB primarily affected the digestibility of Val and Phe and resulted in reduced BWG at d 14. These findings underscore the critical role of proper heat processing in preserving the nutritional quality of ESB in broiler diets, influencing optimal growth performance, and maintaining intestinal health.

Counteracting Roles of Lipidic Aldehydes and Phenolic Antioxidants on Soy Protein Oxidation Defined by a Chemometric Survey of Solvent and Mechanically Extracted Soybean Meals

Soybean meal (SBM) is a premier source of protein for feeding food-producing animals. However, its nutritional value can be compromised by protein oxidation. In this study, a total of 54 sources of solvent extracted SBM (SSBM) and eight sources of mechanically extracted SBM (MSBM), collected from different commercial producers and geographic locations in the United States during the years 2020 and 2021, were examined by chemometric analysis to determine the extent of protein oxidation and its correlation with soybean oil extraction methods and non-protein components. The results showed substantial differences between SSBM and MSBM in the proximate analysis composition, protein carbonyl content, lipidic aldehydes, and antioxidants, as well as subtle differences between 2020 SSBM and 2021 SSBM samples in protein oxidation and moisture content. Correlation analysis further showed positive correlations between protein carbonyl content and multiple lipid parameters, including the ether extract, p-anisidine value, individual aldehydes, and total aldehydes. Among the antioxidants in SBM, negative correlations with protein carbonyl content were observed for total phenolic content and isoflavone glycoside concentrations, but not for Trolox equivalent antioxidant capacity (TEAC), α-tocopherol, and γ-tocopherol. Overall, soybean oil extraction methods, together with other factors such as enzyme treatment and environmental conditions, can significantly affect the proximate analysis composition, the protein and lipid oxidation status, and the antioxidant profile of SBM. Lipidic aldehydes and phenolic antioxidants play counteracting roles in the oxidation of soy protein. The range of protein carbonyl content measured in this study could serve as a reference to evaluate the protein quality of SBM from various sources used in animal feed.

Potential implications of oxidative modification on dietary protein nutritional value: A review

During food processing and storage, proteins are sensitive to oxidative modification, changing the structural characteristics and functional properties. Recently, the impact of dietary protein oxidation on body health has drawn increasing attention. However, few reviews summarized and highlighted the impact of oxidative modification on the nutritional value of dietary proteins and related mechanisms. Therefore, this review seeks to give an updated discussion of the effects of oxidative modification on the structural characteristics and nutritional value of dietary proteins, and elucidate the interaction with gut microbiota, intestinal tissues, and organs. Additionally, the specific mechanisms related to pathological conditions are also characterized. Dietary protein oxidation during food processing and storage change protein structure, which further influences the in vitro digestion properties of proteins. In vivo research demonstrates that oxidized dietary proteins threaten body health via complicated pathways and affect the intestinal microenvironment via gut microbiota, metabolites, and intestinal morphology. This review highlights the influence of oxidative modification on the nutritional value of dietary proteins based on organs and the intestinal tract, and illustrates the necessity of appropriate experimental design for comprehensively exploring the health consequences of oxidized dietary proteins.

Effects of oxidized rice bran protein induced by rancidity on the hepatic function in mice

Rice bran protein (RBP) is a great resource of premium protein. However, rice bran (RB) rancidity, which inevitably occurs during rice milling, can induce RBP oxidation, further affecting the nutritional value of RBP. This study focused on the impact of RBP rancidity on the nutritional value of oxidized RBP. RBP with varying oxidation degrees and doses was given to mice via a 12-week intragastric administration. Oxidized RBP interfered with hepatic function and inflammation, and decreased the antioxidant capacities of the liver. Oxidized RBP also disturbed the hepatic lipid metabolism, and excessively oxidized RBP caused intrahepatic lipid accumulation and hepatic damage. Furthermore, oxidized RBP triggered the MyD88/NF-κB pathway but inhibited the Keap1-Nrf2/ARE pathway in the liver. Correlation analysis revealed that the protein expression of the Nrf2 pathway was negatively correlated with the NF-κB pathway. Results implied that oxidized RBP induced hepatic damage and hepatic dysfunction, indicating the deteriorating nutrition of oxidized RBP. The results exhibited the nutritional value of RBP after oxidative modification, and implied the importance of optimizing food-processing strategies to reduce the degree of protein oxidation, thereby avoiding the nutritional loss of dietary protein.

Effects of heat treatment on protein molecular structure and in vitro digestion in whole soybeans with different moisture content

The effects of heat treatment on protein structure and in vitro digestibility in whole soybeans with different moisture content (10.68%, 29.70%, 46.29%, and 62.05% wet basis) were investigated. Scanning electronic microscopy presented that thermal treatment destroyed the subcellular structure of soybean seeds and resulted in formation of protein aggregates. When β-conglycinin (7S) was heat-denatured, the protein aggregates were maintained mainly by hydrogen bonds and hydrophobic interactions (non-covalent) for each moisture content. Also, the decrease of the protein solubility and increase of in vitro digestibility were observed. However, when glycinin (11S) was denatured in soybeans with 10.68% and 29.70% moisture content, the insoluble and indigestible protein aggregates with protein oxidation-induced crosslinking and high content of β-sheet were presented; in contrast, for 46.29% and 62.05% moisture content, mild protein oxidation, low content of β-sheet, non-covalent interactions and increased protein digestibility were shown. Non-covalent interactions were shown a positive correlation with gastrointestinal digestibility (r = 0.59, p < 0.05). Meanwhile, protein oxidation or β-sheet content was significantly negatively correlated with in vitro protein digestibility (r = -0.69 and -0.61, respectively, p < 0.05). Protein structure rather than solubility contributed to difference of in vitro digestibility. The optimum thermal conditions to obtain high-quality digestible protein in whole soybeans are 160 °C for 10.68%, 145 °C for 29.70%, 160 °C for 46.29% and 115 °C/140 °C for 62.05% moisture content.

Effects of Bacillus methylotrophicus SY200 Supplementation on Growth Performance, Antioxidant Status, Intestinal Morphology, and Immune Function in Broiler Chickens

The present study was focused on evaluating the effects of Bacillus methylotrophicus SY200 in broiler production. A total of 120 healthy 7-day-old broiler chicks were randomly assigned to four dietary treatments, which included basal diet supplemented with 0%, 0.10%, 0.25%, or 0.50% (w/w) B. methylotrophicus SY200 preparation (1.0 × 10⁹ cfu/g), regarded as negative control group (NC), low-dose group (BML), medium-dose group (BMM), and high-dose group (BMH), respectively. Each treatment was fed the corresponding experimental diet for 35 days. Results showed that dietary supplementation of B. methylotrophicus SY200 could improve broiler weight gain, especially the finisher phase. Further studies suggested that a certain amount of B. methylotrophicus SY200 enhanced the broiler antioxidant status and improved the morphological development of jejunum. Besides, dietary supplementation of B. methylotrophicus SY200 especially in 0.50% levels significantly increased the relative weight of immune organs and Newcastle disease virus antibody titer, similarly, increased mRNA expression levels of claudin-1, claudin-3, zonula occluden-1, and zonula occluden-2 were observed in the jejunum of BMM group. Moreover, B. methylotrophicus SY200 also showed beneficial effects in improving broilers microbiota homeostasis by increasing the number of beneficial bacteria. Conclusively, B. methylotrophicus SY200 could effectively improve the antioxidant status, modulate the intestinal structure, enhance the intestinal mucosal barrier function, and regulate the immune function of broilers, which finally improves the performance of the chicken in the finisher period.

Measures Matter-Determining the True Nutri-Physiological Value of Feed Ingredients for Swine

Many types of feed ingredients are used to provide energy and nutrients to meet the nutritional requirements of swine. However, the analytical methods and measures used to determine the true nutritional and physiological ("nutri-physiological") value of feed ingredients affect the accuracy of predicting and achieving desired animal responses. Some chemical characteristics of feed ingredients are detrimental to pig health and performance, while functional components in other ingredients provide beneficial health effects beyond their nutritional value when included in complete swine diets. Traditional analytical procedures and measures are useful for determining energy and nutrient digestibility of feed ingredients, but do not adequately assess their true physiological or biological value. Prediction equations, along with ex vivo and in vitro methods, provide some benefits for assessing the nutri-physiological value of feed ingredients compared with in vivo determinations, but they also have some limitations. Determining the digestion kinetics of the different chemical components of feed ingredients, understanding how circadian rhythms affect feeding behavior and the gastrointestinal microbiome of pigs, and accounting for the functional properties of many feed ingredients in diet formulation are the emerging innovations that will facilitate improvements in precision swine nutrition and environmental sustainability in global pork-production systems.

Hydrogen peroxide-induced oxidative stress impairs redox status and damages aerobic metabolism of breast muscle in broilers

Oxidative stress has always been a hot topic in poultry science. However, studies concerning the effects of redox status and glucose metabolism induced by hydrogen peroxide (H₂O₂) in the breast muscle of broilers have been rarely reported. This study was aimed to evaluate the impact of intraperitoneal injection of H₂O₂ on oxidative damage and glycolysis metabolism of breast muscle in broilers. We also explored the activation of the nuclear factor erythroid 2–related factor 2 (Nrf2) signaling pathway to provide possible mechanism of the redox imbalance. Briefly, a total of 320 one-day-old Arbor Acres chicks were randomly divided into 5 treatments with 8 replicates of 8 birds each (noninjected control, 0.75% saline-injected, 2.5, 5.0, and 10.0% H₂O₂-injected treatments). Saline group was intraperitoneally injected with physiological saline (0.75%) and H₂O₂ groups received an intraperitoneal injection of H₂O_2. The dosage of the injection was 1.0 mL/kg BW. All birds in the saline and H₂O₂ groups were injected on days 16 and 37 of the experimental period. At 42 d of age, 40 birds (8 cages per group and one chicken per cage) were selected to be stunned electrically (50 V, alternating current, 400 Hz for 5 s each one), and then immediately slaughtered via exsanguination. The results showed that broilers in the H₂O₂ injection group linearly exhibited higher contents of reactive oxygen species, carbonyl and malondialdehyde, and lower total antioxidant capacity and glutathione peroxidase activities. With the content of H₂O₂ increased, the H₂O₂ groups linearly downregulated the mRNA expressions of GPX, CAT, HMOX1, NQO1, and Nrf2 and its downstream target genes. In addition, H₂O₂ increased serum activities of creatine kinase and lactate dehydrogenase. Meanwhile, in the pectoral muscle, the glycogen content was linearly decreased, and the lactate content was linearly increased in muscle of broilers injected with H₂O₂. In addition, the activities of glycolytic enzymes including pyruvate kinase, hexokinase, and lactate dehydrogenase were linearly increased after exposure to H₂O₂. In conclusion, H₂O₂ injection could impair antioxidant status and enhance anaerobic metabolism of breast muscle in broilers.

Antioxidant Defence Systems and Oxidative Stress in Poultry Biology: An Update

Poultry in commercial settings are exposed to a range of stressors. A growing body of information clearly indicates that excess ROS/RNS production and oxidative stress are major detrimental consequences of the most common commercial stressors in poultry production. During evolution, antioxidant defence systems were developed in poultry to survive in an oxygenated atmosphere. They include a complex network of internally synthesised (e.g., antioxidant enzymes, (glutathione) GSH, (coenzyme Q) CoQ) and externally supplied (vitamin E, carotenoids, etc.) antioxidants. In fact, all antioxidants in the body work cooperatively as a team to maintain optimal redox balance in the cell/body. This balance is a key element in providing the necessary conditions for cell signalling, a vital process for regulation of the expression of various genes, stress adaptation and homeostasis maintenance in the body. Since ROS/RNS are considered to be important signalling molecules, their concentration is strictly regulated by the antioxidant defence network in conjunction with various transcription factors and vitagenes. In fact, activation of vitagenes via such transcription factors as Nrf2 leads to an additional synthesis of an array of protective molecules which can deal with increased ROS/RNS production. Therefore, it is a challenging task to develop a system of optimal antioxidant supplementation to help growing/productive birds maintain effective antioxidant defences and redox balance in the body. On the one hand, antioxidants, such as vitamin E, or minerals (e.g., Se, Mn, Cu and Zn) are a compulsory part of the commercial pre-mixes for poultry, and, in most cases, are adequate to meet the physiological requirements in these elements. On the other hand, due to the aforementioned commercially relevant stressors, there is a need for additional support for the antioxidant system in poultry. This new direction in improving antioxidant defences for poultry in stress conditions is related to an opportunity to activate a range of vitagenes (via Nrf2-related mechanisms: superoxide dismutase, SOD; heme oxygenase-1, HO-1; GSH and thioredoxin, or other mechanisms: Heat shock protein (HSP)/heat shock factor (HSP), sirtuins, etc.) to maximise internal AO protection and redox balance maintenance. Therefore, the development of vitagene-regulating nutritional supplements is on the agenda of many commercial companies worldwide.