Effects of dietary concentrations of methionine on growth performance and oxidative status of broiler chickens with different hatching weight

Insight into the differences in meat quality among three breeds of sheep on the Qinghai-Tibetan plateau from the perspective of metabolomics and rumen microbiota

Mutton is one of the most popular meats among the general public due to its high nutritional value. This study evaluated the differences in meat quality among Chaka (CK), Black Tibetan (BT) and Oula (OL) sheep and investigated the metabolic mechanisms affecting meat quality using targeted and untargeted metabolomics and 16S rRNA. The results showed that the meat quality of CK sheep was superior to that of BT and OL sheep in terms of meat color, muscle fiber characteristics and nutritional quality. Pseudobutyrivibrio, Alloprevotella, Methanobrevibacter, unidentified_Christensenellaceae, and unidentified_Bacteroidales were key microbes involved in regulating meat color, muscle fiber characteristics, amino acid and fatty acid content. Protein digestion/absorption, pentose phosphate metabolism, carbon metabolism, and glyoxylate and dicarboxylate metabolism were important metabolic pathways involved in meat quality regulation. Our study is important for the development of sheep breeding strategy and sheep meat industry in Qinghai-Tibetan Plateau.

Methionine and vitamin E supplementation improve production performance, antioxidant potential, and liver health in aged laying hens

Sulfur metabolites of methionine (Met) and vitamin E (VE) have antioxidant potential and can maintain liver health in chickens. This study explored the underlying mechanisms of Met sources, the ratio of total sulfur amino acids to lysine (TSAA: Lys), and VE levels on production performances, antioxidant potential, and hepatic oxidation in aged laying hens. Eight hundred and sixty-four, Hy-Line Brown laying hens (70-week age) were divided into 12 treatment groups, each having 6 repeats and 12 birds/each repeat. The dietary treatments consisted of DL-Met (DL-Met), DL-2-hydroxy-4-(methylthio)-butanoic acid (OH-Met), 3 ratios of TSAA: Lys (0.90, 0.95, and 1.00), and 2 levels of VE (20 and 40 g/ton). Albumen height and Haugh unit significantly increased at a lower level of VE (P < 0.05). Triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL) in serum and superoxide dismutase (SOD) and catalase activities (CAT) in the liver significantly reduced at 0.95 TSAA: Lys ratio (P < 0.05). Fatty acid synthase (FAS), lipoprotein lipase (LPL), nuclear factor erythroid 2-related factor 2 (Nrf2), and carnitine palmitoyltransferase-1 alpha (CPT-1α) also upregulated at this TSAA: Lys ratio (P < 0.05). Compared with the DL-Met group, the OH-Met group had lower Dipeptidyl Peptidase 4 (DPP4) and higher TC, LDL, and VLDL concentrations (P < 0.05).The expression of FAS,CPT-1α), glutathione (GSH), glutathione disulfide (GSSG), glutathione synthetase (GSS), and Nrf2 were significantly higher in OH-Met compared with the DL-Met group (P < 0.05). OH-Met at 0.95 and DL-Met at 0.90 TSAA: Lys ratio showed higher CAT and lower aspartate aminotransferase (AST) activities. Moreover, OH-Met at 0.90 and DL-Met at 0.95 of the TSAA: Lys ratio had a significant reduction of malondialdehyde (MDA) (P < 0.05). Overall, these results suggest that OH-Met source with a lower level of VE positively influenced production performance and improved liver health in aged laying hens through improved lipid metabolism and hepatic antioxidant function.

Linking gastrointestinal tract structure, function, and gene expression signatures to growth variability in broilers: a novel interpretation for flock uniformity

Variation in body weight (BW) within broiler flocks is a significant challenge in poultry production. Investigating differences in gut-related parameters between low (LBW) and high BW (HBW) chicks may provide insights into the underlying causes of BW heterogeneity. 908 day-old male broiler chicks were reared until d 7 and then ranked into LBW and HBW groups. Thereafter, performance parameters were compared between BW groups periodically. On d 7, 14, and 38, visceral organ characteristics, intestinal permeability, and duodenal and ileal histomorphology were examined. Expression profiles were analyzed for 79 ileal genes related to gut barrier function, immune function, nutrient transport, gut hormones, nutrient receptors, metabolism, and oxidation using high-throughput qPCR. Student's t-tests were performed to compare measurements. Multivariate statistics, including partial least square regression (PLSR) analysis, were applied to identify combinations of key genes discriminating BW groups, offering predictive capability for phenotypic variations. The HBW group remained heavier at each timepoint, which could be explained by higher feed intake. The HBW group had shorter relative small intestine length but higher villus height and villi height/crypt depth ratios. The LBW group demonstrated increased intestinal permeability on d 38. The LBW group showed upregulation of immune response genes including TNF-α on d 7 and CYP450 on d 38, while the HBW group showed higher AHSA1 and HSPA4 expressions on d 7. The LBW group had upregulation of the metabolism genes mTOR and EIF4EBP1 on d 7 and the satiety-induced hormone cholecystokinin on d 14, while the HBW group tended to increase expression of the hunger hormone ghrelin on d 38. Genes related to gut barrier function, nutrient transport, and oxidation categories were consistently upregulated in the HBW group. PLSR models revealed 4, 12, and 11 sets of key genes highly predictive of BW phenotypes on d 7, 14, and 38, respectively. These findings suggest that growth rates are linked to the intestinal size, structure, and function of broiler chickens, offering insights into the underlying mechanisms regulating BW.

Urbanisation-associated shifts in the avian metabolome within the annual cycle

While organisms have evolved to cope with predictable changes in the environment, the rapid rate of current global change presents numerous novel and unpredictable stressors to which organisms have had less time to adapt. To persist in the urban environment, organisms must modify their physiology, morphology and behaviour accordingly. Metabolomics offers great potential for characterising organismal responses to natural and anthropogenic stressors at the systems level and can be applied to any species, even without genomic knowledge. Using metabolomic profiling of blood, we investigated how two closely related species of passerine bird respond to the urban environment. Great tits Parus major and blue tits Cyanistes caeruleus residing in urban and forest habitats were sampled during the breeding (spring) and non-breeding (winter) seasons across replicated sites in southern Sweden. During breeding, differences in the plasma metabolome between urban and forest birds were characterised by higher levels of amino acids in urban-dwelling tits and higher levels of fatty acyls in forest-dwelling tits. The suggested higher rates of fatty acid oxidation in forest tits could be driven by habitat-associated differences in diet and could explain the higher reproductive investment and success of forest tits. High levels of amino acids in breeding urban tits could reflect the lack of lipid-rich caterpillars in the urban environment and a dietary switch to protein-rich spiders, which could be of benefit for tackling inflammation and oxidative stress associated with pollution. In winter, metabolomic profiles indicated lower overall levels of amino acids and fatty acyls in urban tits, which could reflect relaxed energetic demands in the urban environment. Our metabolomic profiling of two urban-adapted species suggests that their metabolism is modified by urban living, though whether these changes represent adaptative or non-adaptive mechanisms to cope with anthropogenic challenges remains to be determined.

Effect of dietary methionine to crude protein ratio on performance of Ross 308 broiler chickens aged 22 to 42 days

An experiment was conducted to determine the effect of dietary methionine to crude protein (CP) ratio on the performance of male Ross 308 broiler chickens aged 22 to 42 days. The diets were isocaloric and isonitrogenous but with different methionine-to-CP ratios. The diets, based on methionine to crude protein ratios, were M0.020 (0.020), M0.025 (0.025) M0.030 (0.030), M0.040 (0.040), or M0.045 (0.045). A complete randomized design was used. A quadratic type of equation was used to determine dietary methionine to CP ratios for optimal performance of the chickens. Dietary methionine to CP ratio had no effect (P > 0.05) on feed intake, live weight gain, live weight, feed efficiency, metabolizable energy intake, nitrogen retention, abdominal fat pad weight, breast meat nitrogen and methionine contents, and meat flavour and shear force values of the chickens, but it affected (P < 0.05) CP digestibility, carcass and breast weights, and breast meat tenderness and juiciness. Methionine to CP ratios of 0.039, 0.038, 0.050, and 0.050 were calculated to result in optimal CP digestibility, carcass weight, breast meat tenderness, and juiciness, respectively. These results may imply that dietary methionine to CP ratio requirements for broiler chickens will depend on the production parameter of interest.

Replacement of Vitamin E by an Extract from an Olive Oil By-Product, Rich in Hydroxytyrosol, in Broiler Diets: Effects on Growth Performance and Breast Meat Quality

The hypothesis of this experiment was that a liquid rich in hydroxytyrosol (HT) obtained from "alperujo", an olive oil by-product, could replace part of the added vitamin E (VE) as an antioxidant in poultry diets. There were five diets that differed exclusively in the substitution of supplemental VE (0 to 40 mg/kg, with differences of 10 mg/kg) by HT (30 to 0 mg/kg, with differences of 7.5 mg/kg). The basal diet was based on corn and soybean meal and provided 10 mg VE/kg. From 0 to 39 d of age, the growth performance of the birds was not affected by diet. The birds were slaughtered at 39 d of age to evaluate the quality of the breast, and malonaldehyde concentration, pH, color, and drip loss were measured. In terms of meat lipid oxidation, the combination of 22.5 mg HT/kg and 10 mg of added VE/kg equalized to a diet supplemented with 40 mg VE/kg. Meat color improved in broilers fed 7.5 mg HT/kg and 30 mg VE/kg. It is concluded that once the nutritional requirements of the birds in VE are satisfied, the dietary supplementation with the olive oil by-product rich in HT can be used as a strategy to spare VE in broiler diets.

The Functional Roles of Methionine and Arginine in Intestinal and Bone Health of Poultry: Review

This review explores the roles of methionine and arginine in promoting the well-being of poultry, with a specific focus on their impacts on intestinal and bone health. The metabolic pathways of methionine and arginine are elucidated, highlighting their distinct routes within the avian system. Beyond their fundamental importance in protein synthesis, methionine and arginine also exert their functional roles through their antioxidant capacities, immunomodulating effects, and involvement in the synthesis of metabolically important molecules such as S-adenosylmethionine, nitric oxide, and polyamines. These multifaceted actions enable methionine and arginine to influence various aspects of intestinal health such as maintaining the integrity of the intestinal barrier, regulating immune responses, and even influencing the composition of the gut microbiota. Additionally, they could play a pivotal role in promoting bone development and regulating bone remodeling, ultimately fostering optimal bone health. In conclusion, this review provides a comprehensive understanding of the potential roles of methionine and arginine in intestinal and bone health in poultry, thereby contributing to advancing the nutrition, overall health, and productivity of poultry in a sustainable manner.

Functional properties of amino acids: improve health status and sustainability

The combination of increased genetic potential and changes in management strategies (i.e., antibiotic-free, no antibiotics ever, and every day feeding of replacement pullets) influences the nutritional needs of poultry. Traditionally, nutritionists have focused on meeting the amino acid needs for production performance and yield however, increasing specific amino acid concentrations can benefit gastrointestinal development and integrity, enhance immune response potential, influence behavior, and benefit sustainability. Commercialization of additional feed grade amino acids beyond methionine, lysine, and threonine, enables targeted increases to achieve these benefits. As such, this paper addresses the functional roles of amino acids in meeting poultry production, health, and sustainability goals.

Magnolol additive improves growth performance of Linwu ducklings by modulating antioxidative status

Magnolol is a bioactive polyphenolic compound commonly found in Magnolia officinalis. The aim of this study is to clarify the contribution of the magnolol additive on the growth performance of Linwu ducklings aging from 7 to 28 d, comparing to the effects of antibiotic additive (colistin sulphate). A total of 325, 7-d-old ducklings were assigned to 5 groups. Each group had 5 cages with 13 ducklings in each cage. The ducklings in different groups were fed with diets supplemented with 0, 100, 200 and 300 mg/kg magnolol additive (MA) (Control, MA100, MA200 and MA300) and 30 mg/kg colistin sulphate (CS30) for 3 weeks, respectively. Parameters regarding to the growth performance, intestinal mucosal morphology, serum biochemical indices, antioxidant and peroxide biomarkers and the expression levels of antioxidant-related genes were evaluated by one way ANOVA analysis. The results showed that 30 mg/kg colistin sulphate, 200 and 300 mg/kg magnolol additive improved the average final weight (P = 0.045), average daily body weight gain (P = 0.038) and feed/gain ratios (P = 0.001) compared to the control group. 200 and 300 mg/kg magnolol additive significantly increased the villus height/crypt depth ratio of ileum, compared to the control and CS30 groups (P = 0.001). Increased serum level of glucose (P = 0.011) and total protein (P = 0.006) were found in MA200 or MA300 group. In addition, comparing to the control and CS30 groups, MA200 or MA300 significantly increased the levels of superoxide dismutase (P = 0.038), glutathione peroxidase (P = 0.048) and reduced glutathione (P = 0.039) in serum. Moreover, the serum and hepatic levels of 8-hydroxy-2'-deoxyguanosine (P = 0.043 and 0.007, respectively) were lower in all MA groups compared to those of the control and CS30 group. The hepatic mRNA expression levels of superoxide dismutase-1, catalase and nuclear factor erythroid-2-related factor 2/erythroid-derived CNC-homology factor were also increased significantly in MA200 and MA300 groups (P < 0.05). Taken together, these data demonstrated that MA was an effective feed additive enhancing the growth performance of Linwu ducklings at 7 to 28 d by improving the antioxidant and intestinal mucosal status. It suggested that MA could be a potential ingredient to replace the colistin sulphate in diets.

Impact of drinking water supplemented 2-hydroxy-4-methylthiobutyric acid in combination with acidifier on performance, intestinal development, and microflora in broilers

In addition to offering methionine, 2-hydroxy-4-methylthiobutyric acid (HMTBa) is also an organic acid and shows excellent bacteriostasis. Therefore, 3 experiments were conducted to determine the influence of drinking water supplemented HMTBa in combination with acidifier on performance, intestinal development, and microflora in broilers. The addition of different concentration (0.02–0.20%) of the blend of HMTBa and other acids significantly reduced the pH of water and exerted antimicrobial activity in dose-dependent manner in vitro. The outcomes from animal trial consisting of the drinking water with blended acidifier at 0.00, 0.05, 0.10, 0.15, and 0.20% indicated that the water with 0.15 or 0.20% acidifier resulted in linear and quadratic higher body weight at 42 d, gain and water consumption during 1 to 42 d (P < 0.05). In experiment 3, responding to graded blended acidifier in drinking water, birds receiving 0.10, 0.15, and 0.20% acidifier decreased the internal pH of gastrointestinal tract and muscle, and exhibited increased duodenal weight, length, villus high, and the ratio of villus high to crypt depth. Drinking water with 0.2% blended acidifier increased the abundance of probiotics (Bacteroidaceae, Ruminococcaceae, and Lachnospiraceae) and decreased the account of pathogenic bacteria such as Desulfovibrionaceae. Alternations in gut microflora were closely related to the metabolism of carbohydrate, amino acid, and vitamins. These findings, therefore, suggest that drinking water with 0.10 to 0.13% the combination HMTBa with acidifier might benefit to intestinal development and gut microbiota, and the subsequent produce a positive effect on the performance of broilers.

Corn Silage Supplemented with Pomegranate (Punica granatum) and Avocado (Persea americana) Pulp and Seed Wastes for Improvement of Meat Characteristics in Poultry Production

In the present study, pomegranate peels, avocado peels, and seed vacuum microwave extraction solid by-products were supplemented in corn silage in order to investigate the effects on meat quality and growth rate in broiler chicken. There were 50 broilers, divided in two groups, treated with experimental or usual feed for 43 days (group A: 25 broilers fed with avocado and pomegranate by-products and group B: 25 broilers fed with corn-silage used as control). The results showed that broiler chickens fed with a diet supplemented with a mixture of pomegranate avocado by-products (group A) showed significant differences in chicken leg meat quality, significantly improving the level of proteins and fatty acids content in breast and leg meat, respectively. More specific ω3 and ω6 fatty acids content were three times higher than in group B. Moreover, a protective effect on the decomposition of polyunsaturated fatty acids, induced by free radicals and presented in chicken meat, is based on the evaluation of lipid peroxidation by measuring thiobarbituric acid reactive substances. Pomegranate peels, avocado peels, and seed by-products appeared to have a slight reduction on meat production, while it was found to improve the qualitative chicken meat characteristics. Regarding the production costs, it was calculated that the corn-silage supplementation, used in this study, lead to a 50% lower cost than the commercial corn-silage used for the breeding of broilers.

Transcriptomic and metabolomic characterization of post-hatch metabolic reprogramming during hepatic development in the chicken

BACKGROUND

Artificial selection of modern meat-producing chickens (broilers) for production characteristics has led to dramatic changes in phenotype, yet the impact of this selection on metabolic and molecular mechanisms is poorly understood. The first 3 weeks post-hatch represent a critical period of adjustment, during which the yolk lipid is depleted and the bird transitions to reliance on a carbohydrate-rich diet. As the liver is the major organ involved in macronutrient metabolism and nutrient allocatytion, a combined transcriptomics and metabolomics approach has been used to evaluate hepatic metabolic reprogramming between Day 4 (D4) and Day 20 (D20) post-hatch.

RESULTS

Many transcripts and metabolites involved in metabolic pathways differed in their abundance between D4 and D20, representing different stages of metabolism that are enhanced or diminished. For example, at D20 the first stage of glycolysis that utilizes ATP to store or release glucose is enhanced, while at D4, the ATP-generating phase is enhanced to provide energy for rapid cellular proliferation at this time point. This work has also identified several metabolites, including citrate, phosphoenolpyruvate, and glycerol, that appear to play pivotal roles in this reprogramming.

CONCLUSIONS

At Day 4, metabolic flexibility allows for efficiency to meet the demands of rapid liver growth under oxygen-limiting conditions. At Day 20, the liver's metabolism has shifted to process a carbohydrate-rich diet that supports the rapid overall growth of the modern broiler. Characterizing these metabolic changes associated with normal post-hatch hepatic development has generated testable hypotheses about the involvement of specific genes and metabolites, clarified the importance of hypoxia to rapid organ growth, and contributed to our understanding of the molecular changes affected by decades of artificial selection.

Dietary Oxidative Distress: A Review of Nutritional Challenges as Models for Poultry, Swine and Fish

The redox system is essential for maintaining cellular homeostasis. When redox homeostasis is disrupted through an increase of reactive oxygen species or a decrease of antioxidants, oxidative distress occurs resulting in multiple tissue and systemic responses and damage. Poultry, swine and fish, raised in commercial conditions, are exposed to different stressors that can affect their productivity. Some dietary stressors can generate oxidative distress and alter the health status and subsequent productive performance of commercial farm animals. For several years, researchers used different dietary stressors to describe the multiple and detrimental effects of oxidative distress in animals. Some of these dietary challenge models, including oxidized fats and oils, exposure to excess heavy metals, soybean meal, protein or amino acids, and feeding diets contaminated with mycotoxins are discussed in this review. A better understanding of the oxidative distress mechanisms associated with dietary stressors allows for improved understanding and evaluation of feed additives as mitigators of oxidative distress.

Secondary Functions of Arginine and Sulfur Amino Acids in Poultry Health: Review

Simple Summary

Historically, studies with amino acids have focused on protein synthesis and accretion, especially with eggs and meat, whereas less importance has been given to their secondary functions on the metabolism. However, certain amino acids, such as arginine, methionine, and cysteine are precursors for other essential molecules in the immune defense, antioxidant system, cell signaling, and gene expression, and can act as regulators in the growth and development of the animals. Because poultry are subjected to stressful conditions throughout their lives, the use of these amino acids and their secondary functions could beneficiate their general health. This review describes the metabolism of arginine, methionine, and cysteine and how they modulate different tissues, especially during challenging conditions. Arginine supplementation has been shown to modulate musculoskeletal health development, reduce fat accretion, and improve the antioxidant system. Moreover, methionine and cysteine could improve the bone development and have a potential in mitigating the negative effects caused by heat stress. Understanding how these amino acids can ameliorate stressful conditions may provide novel insights about their use as nutritional strategies to modulate the health status of chickens.

Abstract

Amino acids such as arginine, methionine, and cysteine are the precursors of essential molecules that regulate growth and health, being classified as functional amino acids. This review describes the metabolism of arginine and the sulfur amino acids and how they modulate, directly or indirectly, different tissues. Emphasis is placed on their effects in supporting health during challenging conditions, such as heat stress and Eimeria infection. The use of arginine has been shown to reduce abdominal fat pad in ducks and increase lean tissue and bone mineral density in broilers. Additionally, the sulfur amino acids have been shown to improve bone development and are beneficial during heat stress. The use of L-methionine increased the cortical and trabecular bone mineral densities, in laying hens. Moreover, the dietary inclusion of these amino acids could reduce the damage caused by Eimeria spp. infection by regulating the antioxidant system and cell repair. Understanding how these amino acids can mitigate stressful conditions may provide us novel insights of their use as nutritional strategies to modulate the health status of chickens.

Supplemental methionine and stocking density affect antioxidant status, fatty acid profiles, and growth performance of broiler chickens

Broilers stocked in high densities may be prone to oxidative and inflammatory insults, resulting in impaired health status, growth performance, and meat quality. This study was to determine if 30% extra supplemental dl-methionine alleviated or prevented those adverse effects of a higher stocking density in broiler chickens. A total of 560 male Cornish Cross cockerels (day old) were divided into four groups: two stocking densities (9 and 12 birds/m2) and two supplementations of methionine (grower: 2.90 or 3.77 g/kg and finisher: 2.60 or 3.38 g/kg). Growth performance was recorded weekly. Blood and tissues were sampled at the end of each period. High stocking density decreased (P < 0.05) body weight and growth performance of growers and (or) finishers. Those differences were partially attenuated by the extra methionine supplementation. The high methionine elevated (P < 0.05) glutathione (GSH) concentration in the thigh at both ages (> 24%). The high stocking density elevated (>28%, P < 0.05) glutathione concentration in the plasma, breast, and thigh of growers, but decreased (P < 0.05) it in the liver of growers and thigh of finishers. Interaction effects (P < 0.05) between dietary methionine and stocking density were found on activities of the antioxidant enzyme glutathione S-transferase in the liver of growers and breast, thigh, and adipose tissue of finishers. The interaction effect was also found on activities of glutathione peroxidase and superoxide dismutase in the thigh of growers. The extra methionine decreased (P < 0.05) hepatic gene expression of heat shock protein 90 (18%) and thigh and breast malondialdehyde concentrations of the finishers (35%). In conclusion, the 30% extra dl-methionine supplementation was able to partially mitigate adverse effects caused by the higher stocking density and to improve the redox status of the broilers.

Effects of graded levels of dietary squalene supplementation on the growth performance, plasma biochemical parameters, antioxidant capacity, and meat quality in broiler chickens

This study was conducted to evaluate the effects of dietary squalene supplementation on the growth performance, plasma biochemical indices, antioxidant status, and meat quality in broilers. Two hundred and forty 0-day-old male chicks were allocated into 5 groups of 6 replicates and were fed a basal diet supplemented with 0 (Control group), 250, 500, 1,000, or 2,000 mg/kg squalene for 42 d. Dietary squalene supplementation linearly increased weight gain and feed efficiency of broilers during the grower and overall periods (P < 0.05). Squalene linearly decreased 21-d malondialdehyde (MDA) level and 42-d glutathione peroxidase (GSH-Px) activity, and both linearly and quadratically decreased 42-d MDA level in plasma (P < 0.05). In contrast, squalene linearly increased plasma reduced form of glutathione (GSH) level on 21 and 42 d and superoxide dismutase activity on 42 d (P < 0.05). Squalene supplementation linearly decreased 21-d MDA accumulation but linearly increased GSH level on 21 d and 42 d and both linearly and quadratically increased 21-d GSH-Px activity in liver (P < 0.05). Supplementing squalene linearly increased pH value at 48 h and linearly decreased lightness at 48 h and 24-h drip loss of breast muscle (P < 0.05). The lightness at 24 h and cooking loss of breast muscle were both linearly and quadratically reduced by squalene (P < 0.05). Dietary squalene administration linearly decreased MDA accumulation but linearly increased GSH level and GSH-Px activity of breast muscle (P < 0.05). Compared with the control group, aforementioned growth performance, antioxidant-related parameters (except 42-d GSH-Px in plasma and breast and hepatic GSH), and meat quality were improved by squalene when its level was 1,000 and 2,000 mg/kg (P < 0.05), with their results being similar between these 2 groups (P > 0.05). It was concluded that squalene administration especially at a level of 1,000 mg/kg can improve growth performance, antioxidant status, and meat quality in broilers, providing insights into its application as a potential feed additive in broiler production.

Maternal dietary methionine supplementation influences egg production and the growth performance and meat quality of the offspring

This study aimed to investigate the effects of maternal dietary coated methionine (Met) on egg production and the quality, growth performance, carcass traits, and meat quality of the offspring. In total, 288 female Ross parental chickens were randomly assigned to 3 groups with 3 replicates of 32 chickens each. From week 37 to 46, the hens of different groups were fed diets containing low (0.27% Met), adequate (0.27% Met + 0.1% coated Met) (AM), and high (0.27% Met + 0.2% coated Met) (HM) Met. There was a positive response in laying rate and albumen weight in AM and HM groups. For the offspring at market age, BW, eviscerated weight, and muscle weight were increased in the AM group (P < 0.05), whereas excessive supplementation was proven to be negative with those traits. The meat quality (color, pH, and shear force) of breast muscle was significantly influenced by different supplementation levels. The lightness and yellowness were increased in the HM group (P < 0.05, P < 0.01, respectively), and redness was decreased in the AM group (P < 0.05). A lower pH value occurred in chickens of the HM group (P < 0.05). The expressions of meat quality–related genes were altered in the supplementation groups. The pH-related genes PRDX4 and PRKAG2 were found to be significantly differentially expressed (P < 0.05, P < 0.01, respectively) and consistent with pH changes. The meat color–related gene BCO1 was also differentially expressed (P < 0.01) and showed a corresponding change with yellowness value. Collectively, the best production performance was in the offspring with 0.1% coated Met supplementation (AM group). Supplementation with 0.2% coated Met (HM group) seemed to be excessive, but laying rate was increased in the HM group. Both results of phenotypic measurements and gene expression demonstrated that maternal-coated Met supplementation resulted in fluctuation of some meat quality indices in the offspring, but all values were still within the range found in normal chickens.

A grape seed extract maternal dietary supplementation in reproductive hens reduces oxidative stress associated to modulation of plasma and tissue adipokines expression and improves viability of offsprings

In reproductive hens, a feed restriction is an usual practice to improve metabolic and reproductive disorders. However, it acts a stressor on the animal. In mammals, grape seed extracts (GSE) reduces oxidative stress. However, their effect on endocrine and tissue response need to be deepened in reproductive hens. Here, we evaluated the effects of time and level of GSE dietary supplementation on growth performance, viability, oxidative stress and metabolic parameters in plasma and metabolic tissues in reproductive hens and their offsprings. We designed an in vivo trial using 4 groups of feed restricted hens: A (control), B and C (supplemented with 0.5% and 1% of the total diet composition in GSE since week 4, respectively) and D (supplemented with 1% of GSE since the hatch). In hens from hatch to week 40, GSE supplementation did not affect food intake and fattening whatever the time and dose of supplementation. Body weight was significantly reduced in D group as compared to control. In all hen groups, GSE supplementation decreased plasma oxidative stress index associated to a decrease in the mRNA expression of the NOX4 and 5 oxidant genes in liver and muscle and an increase in SOD mRNA expression. This was also associated to decreased plasma chemerin and increased plasma adiponectin and visfatin levels. Interestingly, maternal GSE supplementation increased the live body weight and viability of chicks at hatching and 10 days of age. This was associated to a decrease in plasma and liver oxidative stress parameters. Taken together, GSE maternal dietary supplementation reduces plasma and tissue oxidative stress associated to modulation of adipokines without affecting fattening in reproductive hens. A 1% GSE maternal dietary supplementation increased offspring viability and reduced oxidative stress suggesting a beneficial transgenerational effect and a potential use to improve the quality of the progeny in reproductive hens.

Modelling Methionine Requirements of Fast- and Slow-Growing Chinese Yellow-Feathered Chickens during the Starter Phase

Simple Summary

In poultry production, consuming diets with low or excessive methionine levels leads to negative effects on growth performance. The requirements of methionine may differ among the fast and slow-growing breeds; therefore, the optimal dietary methionine level should be estimated for each. In this study, six dietary methionine levels were evaluated to estimate the optimal level for fast and slow-growing yellow feathered chicken breeds. The quadratic polynomial and exponential asymptotic regression showed that the optimal methionine requirements for maximal growth performance were 0.50% and 0.53% in the fast-growing breed, and 0.48% and 0.52% in the slow growing breed.

Abstract

Two experiments were carried out to investigate the dietary methionine requirement for fast and slow-growing Chinese yellow-feathered breeds during the starter phase, based on growth variables and regression models. In Experiment 1, a total of 2880 one-day-old Lingnan chicks (fast growing breed) were used to test the methionine requirement from 1 to 21 days of age for males and females separately. Of each gender, 1440 birds were allocated into 6 dietary methionine levels (0.28%, 0.32%, 0.37%, 0.43%, 0.50% and 0.63%), each with 6 pen replicates of 40 chicks. Experiment 2 had the same design with Guangxi chicks (slow growing breed) from 1 to 30 d of age. Results indicated that significant nonlinear or quadratic responses to increasing dietary methionine levels were observed in body weight, daily gain, feed intake and feed conversion ratio of both breeds. In summary, the quadratic polynomial regression showed that the optimal methionine requirements for maximal growth performance of Lingnan chickens were 0.52–0.58% in males, 0.51% in females, and 0.53% in mixed genders. The corresponding values for Guangxi breed were 0.53% in males by quadratic polynomial regression and 0.43% in females, and 0.48% to 0.49% in mixed sexes by exponential asymptotic models.

Supplemental methionine exerted chemical form-dependent effects on antioxidant status, inflammation-related gene expression, and fatty acid profiles of broiler chicks raised at high ambient temperature1

This study was to explore metabolic effects of two forms and concentrations of supplemental methionine in grower and finisher diets for broiler chickens raised at high temperature. Male Cornish cockerel chicks (total = 360, day-old) were divided into four groups (10 pens/treatment, 9 chicks/pen) and fed with 100% or 130% required methionine in the diets as DL-methionine (DL-MET) or 2-hydroxy-4-(methylthio)butanoate (HMTBA). The room was maintained at 4 to 13 °C above the suggested thermoneutral temperature. The higher concentration of both DL-MET and HMTBA enhanced (P < 0.05) hepatic GSH concentrations of the growers and plasma ferric reducing ability of the finishers. The DL-MET-fed growers had greater (P < 0.05%) muscle GSH and hepatic unsaturated fatty acid concentrations than those fed HMTBA. Expression of inflammation-related genes in the liver of finishers was affected (P < 0.05) by interaction effects of the methionine form and concentration. In conclusion, effects of the extra methionine supplementation on the high ambient temperature-related metabolic responses of broilers varied with their age and(or) tissue and the methionine form.

Magnolol additive improves carcass and meat quality of Linwu ducks by modulating antioxidative status

Magnolol rich in Magnolia officinalis is a bioactive polyphenolic compound. The aim of this study was to clarify the effects of magnolol additive (MA) on carcass and meat quality, biochemical characteristics and antioxidative capacity of Linwu ducks, by comparing it to that of antibiotic additive (colistin sulphate, CS). A total of 275 49-d-old ducks were randomly assigned to 5 groups with 5 cages of 11 ducks each and fed by the diets supplemented with 0, 100, 200 and 300 mg of MA/kg and 30 mg of CS/kg for 3 weeks, respectively. The results revealed that MA administration not only increased dressed percentage (calculated as a percentage of live weight), percentage of breast muscle, leg muscle and lean meat (calculated as a percentage of eviscerated weight), but also remarkably increased a*_{45 min} and pH_{45 min} of leg muscle. Moreover, MA administration decreased the percentage of abdominal fat (calculated as a percentage of eviscerated weight), 45-min cooking loss, water loss rate of leg muscle, 45-min cooking loss and drip loss of breast muscle at 24 hr and 48 hr. Furthermore, MA administration enhanced the activities of superoxide dismutase and catalase in serum or liver, serum total antioxidant capacity and hepatic reduced glutathione concentration significantly, compared with the basal diet or CS group (p < .05). On the other hand, triglyceride, total cholesterol, aspartate aminotransferase, malondialdehyde, protein carbonyl and 8-hydroxy-2'-deoxyguanosine contents in serum and liver were significantly increased in Linwu ducks fed with CS, compared with MA groups (p < .05). Taken together, these data demonstrated that magnolol could effectively improve the carcass and meat quality of Linwu ducks by regulating the in vivo antioxidant status and would be a potential candidate to replace antibiotic.

Effects of dietary methionine supplementation on growth performance, intestinal morphology, antioxidant capacity and immune function in intra-uterine growth-retarded suckling piglets

This study investigated the effects of dietary supplementation with L -methionine (L -Met), DL -methionine (DL -Met) and calcium salt of the methionine hydroxyl analog (MHA-Ca) on growth performance, intestinal morphology, antioxidant capacity and immune function in intra-uterine growth-retarded (IUGR) suckling piglets. Six normal birthweight (NBW) female piglets and 24 same-sex IUGR piglets were selected at birth. Piglets were fed nutrient adequate basal diet supplemented with 0.08% L -alanine (NBW-CON), 0.08% L -alanine (IUGR-CON), 0.12% L -Met (IUGR-LM), 0.12% DL -Met (IUGR-DLM) and 0.16% MHA-Ca (IUGR-MHA-Ca) from 7 to 21 days of age respectively (n = 6). The results indicated that IUGR decreased average daily milk (dry matter) intake and average daily gain and increased feed conversion ratio of suckling piglets (p < 0.05). Compared with the NBW-CON piglets, IUGR also impaired villus morphology and reduced antioxidant capacity and immune homeostasis in the intestine of IUGR-CON piglets (p < 0.05). Supplementation with L -Met enhanced jejunal villus height (VH) and villus area and ileal VH of IUGR piglets compared with IUGR-CON piglets (p < 0.05). Similarly, DL -Met supplementation increased VH and the ratio of VH to crypt depth in the jejunum compared with IUGR-CON pigs (p < 0.05). Supplementation with L -Met and DL -Met (0.12%) tended to increase reduced glutathione content and reduced glutathione: oxidized glutathione ratio and decrease protein carbonyl concentration in the jejunum of piglets when compared with the IUGR-CON group (p < 0.10). However, supplementation with MHA-Ca had no effect on the intestinal redox status of IUGR piglets (p > 0.10). In conclusion, supplementation with either L -Met or DL -Met has a beneficial effect on the intestinal morphology and antioxidant capacity of IUGR suckling piglets.

Effects of in ovo injection of sulfur-containing amino acids on heat shock protein 70, corticosterone hormone, antioxidant indices, and lipid profile of newly hatched broiler chicks exposed to heat stress during incubation

This study hypothesizes that in ovo sulfur amino acids (SAA) injection can alleviate the heat or oxidative stress of hatched chicks. Thus, the study aimed to assess the impact of in ovo injection of SAA with heat stress during the incubation on heat shock protein 70 (HSP70), corticosterone hormone, antioxidant indices, and lipid profile of newly hatched broiler chicks. Eggs were incubated under optimal incubation temperature (37.8°C) from days 1 to 10 then under high temperature (39.6°C for 6 h daily) between 10 and 18 D of the incubation. At day 17.5 of incubation, 150 eggs were randomly divided into 3 groups of 50 replicate eggs. The first group served as control (non-injected group, NIG), the second group was only injected with saline solution (saline-injected group, SIG), and the third group was injected with a mixture of 5.90 mg L-methionine plus 3.40 mg L-cysteine (sulfur amino acids-injected group, SAAIG). The results exhibited that serum HSP70 and corticosterone concentrations were significantly reduced (P < 0.001) in the SAAIG compared with the NIG and SIG. In ovo SAA injection significantly augmented the antioxidant indices in the serum and tissues compared with the NIG and SIG. HSP70 mRNA relative expression was decreased but glutathione peroxidase (GSH-Px) mRNA relative expression was augmented in the tested tissues (P < 0.001) in the SAAIG compared with the NIG. The SAAIG had significantly (P < 0.05) lower levels in serum lipid profile compared to those of the control and SIG. In conclusion, in ovo SAA injection (methionine plus cysteine) in the embryonated eggs exposed to heat stress increased GSH-Px gene expression and antioxidant indices, and reduced HSP70 gene expression, corticosterone concentrations, and lipid profile of newly hatched broiler chicks.

Effects of In Ovo Methionine-Cysteine Injection on Embryonic Development, Antioxidant Status, IGF-I and TLR4 Gene Expression, and Jejunum Histomorphometry in Newly Hatched Broiler Chicks Exposed to Heat Stress during Incubation

Sulfur amino acids are typically the first-limiting amino acids (AA) used in protein metabolism in poultry. Therefore, we hypothesized that their utilization in the pre-hatch period would affect embryonic development, IGF-I and TLR4 gene expression, antioxidant status, serum biochemical profile, and jejunum histomorphometry of newly hatched Ross broiler chicks incubated under heat stress conditions. A total of 150 fertile broiler eggs were subjected to heat stress (39.6 °C for 6 h/d) from d10 until d18 and injected at d 17.5 of incubation with methionine and cysteine (Met-Cys) at a dose of 5.90 mg l-methionine plus 3.40 mg l-cysteine. The effects of Met-Cys administration were examined and compared with the control (Non-injected group) and 0.75% NaCl injected group. The results showed that no significant differences among all groups in serum protein profiles (total protein, albumin, globulin, and albumin/globulin ratio) and creatine kinase were observed. The level of heat shock protein-90 was decreased with Met-Cys In ovo injection. The In ovo injection of Met-Cys also improved the values of total antioxidants capacity and glutathione in examined tissues. At the same time, an increase in fold change mRNA abundance of IGF-I and TLR4 was observed after Met-Cys injection in tested tissues. Finally, an increase of 29% in villus area was found after Met-Cys injection compared to the control group. In conclusion, the In ovo injection of Met-Cys resulted in improved embryonic development, IGF-I and TLR4 gene expression, antioxidant status and jejunum histomorphometry of newly hatched broiler chicks exposed to heat stress during incubation.

Transcriptome analysis of hepatic gene expression and DNA methylation in methionine- and betaine-supplemented geese (Anser cygnoides domesticus)

Dietary methionine (Met) restriction produces a coordinated series of transcriptional responses in the liver that limits growth performance and amino acid metabolism. Methyl donor supplementation with betaine (Bet) may protect against this disturbance and affect the molecular basis of gene regulation. However, a lack of genetic information remains an obstacle to understand the mechanisms underlying the relationship between Met and Bet supplementation and its effects on genetic mechanisms. The goal of this study was to identify the effects of dietary supplementation of Met and Bet on growth performance, transcriptomic gene expression, and epigenetic mechanisms in geese on a Met-deficient diet. One hundred and fifty 21-day-old healthy male Yangzhou geese of similar body weight were randomly distributed into 3 groups with 5 replicates per treatment and 10 geese per replicate: Met-deficient diet (Control), Control+1.2 g/kg of Met (Met), and Control+0.6 g/kg of Bet (Bet). All geese had free access to the diet and water throughout rearing. Our results indicated that supplementation of 1.2 g/kg of Met in Met-deficient feed increased growth performance and plasma homocysteine (HCY) levels, indicating increased transsulfuration flux in the liver. Supplementation of 0.6 g/kg Bet had no apparent sparing effect on Met needs for growth performance in growing geese. The expression of many genes critical for Met metabolism is increased in Met supplementation group. In the Bet-supplemented group, genes involved in energy production and conversion were up-regulated. Dietary supplementation with Bet and Met also altered DNA methylation. We observed changes in the methylation of the LOC106032502 promoter and corresponding changes in mRNA expression. In conclusion, Met and Bet supplementation in geese affects the transcriptional regulatory network and alters the hepatic DNA methylation of LOC106032502.

Effects of dietary methionine on growth performance, meat quality and oxidative status of breast muscle in fast- and slow-growing broilers

This experiment was conducted to investigate the effects of dietary methionine (Met) on growth performance, carcass traits, meat quality and oxidative status of breast muscle in fast- (Arbor Acres, AA) and slow- (Partridge Shank, PS) growing broilers from 1 to 42 d of age. The broilers were divided into a 2 × 3 factorial design with 6 replicates per treatment. Diets were formulated to contain low (LM, 0.35 and 0.31% during 1 to 21 and 22 to 42 d), adequate (AM, 0.50 and 0.44%) and high (HM, 0.65 and 0.57%) Met, respectively. The main effects showed that the AA broilers had superior (P < 0.05) growth performance and carcass traits compared with those of the PS broilers. The breast muscle of the AA broilers had lower (P < 0.05) drip loss and malondialdehyde (MDA) content but higher (P < 0.05) cooking loss and glutathione peroxidase (GPX) activity than that of the PS broilers. Compared with the LM diets, the AM and HM diets increased (P < 0.05) 42-d BW, ADG, eviscerated yield and breast muscle yield only in the AA broilers. The AA broilers fed the HM diets had higher (P < 0.05) pH but lower (P < 0.05) L*, cooking loss and ether extract content in breast muscle than those fed the LM diets. Compared with the LM diets, the HM diets resulted in strain-dependent changes (P < 0.05) in muscle oxidative status, with total antioxidant capacity (T-AOC) increased in the AA broilers, GPX activity increased and MDA content decreased in the PS broilers, and superoxide dismutase (SOD) activity increased in both strains of broilers. No differences were observed between the AM and HM diets except for T-AOC in breast muscle. In conclusion, the LM treatment negatively affected broiler growth performance, carcass traits, meat quality and oxidative status of breast muscle in a strain-dependent manner, particularly in the AA broilers, whereas the HM treatment had limited effects compared to the AM treatment.

The effect of DL-, L-isomers and DL-hydroxy analog administered at 2 levels as dietary sources of methionine on the metabolic and antioxidant parameters and growth performance of turkeys

A hypothesis was verified that dietary methionine (Met) improves the growth and antioxidant status of turkeys, and that its effects depend on dietary inclusion levels and sources. A total of 816 female Hybrid Converter turkeys was fed wheat-soybean meal-based diets supplemented with 3 sources of Met: DL-, L-isomers and DL-hydroxy analog (DLM, LM, and MHA, respectively). In 4 4-week periods (from one to 16 wk of age), dietary Met content corresponded to NRC (1994) recommendations or was increased by approximately 50% (in one to 8 wk by 44 to 46% and in 9 to 16 wk by 55 to 56% vs. the NRC guidelines) to match the recommendations of some breeding companies. Increased Met content resulted in higher final body weights of turkeys (P = 0.002), an improved feed conversion ratio (P = 0.049), increased total glutathione concentration and ferric reducing ability of plasma (FRAP) values, and decreased malondialdehyde (MDA) concentration (all P < 0.001) in the blood plasma of turkeys. In comparison with DLM, LM and MHA contributed to an increase in plasma glutathione concentration (P = 0.001), a decrease in plasma triacylglycerol (P = 0.003) and uric acid (P = 0.001) concentrations, and a decrease in liver MDA (P = 0.001) levels. A decrease in plasma MDA (vs. DLM) and lipid peroxides (LOOH) (vs. DLM and LM) concentrations as well as a decrease in plasma superoxide dismutase (SOD) activity (vs. DLM and LM) also were noted in the MHA treatment (P = 0.016, P = 0.001 and P = 0.011, respectively). In conclusion, the results of the study indicate that the antioxidant status of turkeys could be affected by dietary Met levels and sources. The dietary Met content increased by 50% relative to NRC recommendations, improved the growth performance of turkeys, and strengthened their antioxidant defense system. In comparison with DLM, LM and MHA could be considered positive nutritional factors as manifested by a beneficial decrease in plasma and hepatic MDA concentrations as well as an increase in plasma glutathione levels, and the effect of MHA was more pronounced.

The Effect of Different Dietary Levels and Sources of Methionine on the Growth Performance of Turkeys, Carcass and Meat Quality

The aim of this study was to determine the effect of different dietary levels and sources of methionine (Met) on the growth performance of turkeys, carcass and meat quality. A total of 816 Hybrid Converter turkeys in 6 groups and 8 replications were fed wheat-soybean meal-based diets supplemented with three sources of Met: DL-isomer, L-isomer and DL-hydroxy analog (DLM, LM and MHA, respectively). In four 4-week periods (from 1 to 16 weeks of age), the Met content of turkey diets corresponded to the level recommended by NRC (1994) or was increased by approximately 50% to match the intake recommended by some breeding companies. Increased dietary Met content resulted in a higher final body weight (BW) of turkeys (P=0.002) and a lower feed conversion ratio (FCR) (P=0.049), but had no effect on carcass dressing percentage and most parameters of carcass quality. The higher dietary Met level contributed to a decrease in meat pH, a lower contribution of redness and a smaller muscle fiber diameter (P=0.028, P=0.040 and P=0.004, respectively). The higher dietary Met level had no influence on the redox status of meat, but it reduced the incidence of lymphoid cell infiltration between muscle fibers threefold (P=0.003). Throughout the experiment, no significant differences were noted in the growth performance parameters of turkeys, irrespective of Met source. MHA contributed to higher abdominal fat content, lower dry matter (DM) content and lower catalase (CAT) activity in breast meat, compared with DLM and LM. Increased dietary Met content, approximately 50% higher than that recommended by NRC (1994), regardless of Met source, led to higher final BW of turkeys, but had no effect on carcass dressing percentage and most parameters of carcass quality.

Responses to dietary levels of methionine in broilers medicated or vaccinated against coccidia under Eimeria tenella-challenged condition

Background

Coccidiosis is a prevalent problem in chicken production. Dietary addition of coccidiostats and vaccination are two approaches used to suppress coccidia in the practical production. Methionine (Met) is usually the first limiting amino acid that plays important roles in protein metabolism and immune functions in chickens. The present study is aimed to investigate whether increasing dietary Met levels will improve the anticoccidial effects in broilers medicated or vaccinated against coccidia under Eimeria (E.) tenella-challenged condition. Two thousand male Partridge Shank broiler chicks were obtained from a hatchery. After hatch, birds were weighed, color-marked and allocated equally into two anticoccidial treatments, namely medicated and vaccinated groups. Chicks were either fed, from 1 d of age, diets containing coccidiostat (narasin) or diets without the coccidiostat but were inoculated with an anticoccidial vaccine at 3 d of age. At 22 d of age, 1080 chicks among them were randomly allocated evenly into 6 groups under a 2 × 3 treatment with 2 anticoccidial programs and 3 dietary methionine (Met) levels. Chicks medicated or vaccinated against coccidia were fed diets containing 0.45%, 0.56% or 0.68% of Met from 22 to 42 d of age. All chicks were orally introduced with an amount of 5 × 10⁴ sporulated oocysts of E. tenella at 24 d of age. The growth performance, serum anti-oxidative indexes, intestinal morphology, cecal lesion scores, fecal oocyst counts and immune parameters were measured.

Results

The results showed increasing dietary Met level from 0.45% to 0.56% and 0.68% improved weight gain and feed conversion of broilers medicated against coccidia. In contrast, higher dietary levels of Met did not improve growth performance of the vaccinated chickens. Higher Met levels helped the medicated chickens resist E. tenella infection, as indicated by improved intestinal morphology and immune functions as well as decreased cecal lesion and fecal oocyst counts.

Conclusions

Anticoccidial vaccination is a better strategy for controlling coccidiosis than feeding narasin, due to not only greater growth performance, but also the lower Met supplementation. Furthermore, higher dietary Met levels improved growth performance of chickens medicated rather than vaccinated against coccidia under E. tenella-challenged condition.

Effects of dietary methionine on productivity, reproductive performance, antioxidant capacity, ovalbumin and antioxidant-related gene expression in laying duck breeders

The study investigated whether dietary methionine (Met) affects egg weight and antioxidant status through regulating gene expression of ovalbumin (OVAL), nuclear factor erythroid 2 like 2 (Nrf2) and haem oxygenase 1 (HO-1) in laying duck breeders. Longyan duck breeders (n 540, 19 weeks) were randomly assigned to six treatments with six replicates of fifteen birds each. Breeders were fed diets with six Met levels (2·00, 2·75, 3·50, 4·25, 5·00 and 5·75 g/kg) for 24 weeks. The egg weight (g), egg mass (g/d), feed conversion ratio, hatchability, 1-d duckling weight, albumen weight, albumen proportion and OVAL mRNA level improved with dietary Met levels, whereas yolk proportion decreased (P<0·05). The weight of total large yellow follicles increased linearly (P<0·001) and quadratically (P<0·05) with dietary Met concentration, and their weight relative to ovarian weight showed a linear (P<0·05) effect. Dietary Met level had a linear (P<0·05) and quadratic (P<0·001) effect on the gene expression of glutathione peroxidase (GPX1), HO-1 and Nrf2, and quadratically (P<0·05) increased contents of GPX and total antioxidant capacity (T-AOC) in liver of duck breeders. In addition, maternal dietary Met enhanced gene expression of GPX1, HO-1 and Nrf2, increased contents of GPX and T-AOC and reduced carbonylated protein in the brains of hatchlings. Overall, dietary Met concentration affected egg weight and albumen weight in laying duck breeders, which was partly due to gene expression of OVAL in oviduct magnum. A diet containing 4·0 g Met/kg would achieve optimal hepatic GPX1 and Nrf2 expression, maximise the activity of GPX and minimise lipid peroxidation.

Enhancement of Antioxidant Mechanisms and Reduction of Oxidative Stress in Chickens after the Administration of Drinking Water Enriched with Polyphenolic Powder from Olive Mill Waste Waters

The aim of the study was to examine the effects of a polyphenolic powder from olive mill wastewater (OMWW) administered through drinking water, on chickens' redox status. Thus, 75 chickens were divided into three groups. Group A was given just drinking water, while groups B and C were given drinking water containing 20 and 50 μg/ml of polyphenols, respectively, for 45 days. The antioxidant effects of the polyphenolic powder were assessed by measuring oxidative stress biomarkers in blood after 25 and 45 days of treatment. These markers were total antioxidant capacity (TAC), protein carbonyls (CARB), thiobarbituric acid reactive species (TBARS) and superoxide dismutase activity (SOD) in plasma, and glutathione (GSH) and catalase activity in erythrocytes. The results showed that CARB and TBARS were decreased significantly in groups B and C, and SOD decreased in group B compared to that in group A. TAC was increased significantly in group C and GSH was increased in group B, while catalase activity was increased in groups B and C compared to that in group A. In conclusion, this is the first study showing that supplementation of chickens with polyphenols from OMWW through drinking water enhanced their antioxidant mechanisms and reduced oxidative stress-induced damage.

Feed supplemented with byproducts from olive oil mill wastewater processing increases antioxidant capacity in broiler chickens

In the present study, a ceramic membrane microfiltration method was used for the separation of two liquid products, the downstream permeate and the upstream retentate, from olive mill wastewater (OMWW). These liquid products were examined for their antioxidant activity by incorporating them into broilers' feed. Twenty four broilers 13 d old were divided into two feeding groups receiving supplementation with OMWW retentate or permeate for 37 d. Blood was drawn at 17, 27 and 37 d, while tissues (muscle, heart, liver) were collected at 37 d. The antioxidant effects were assessed by measuring oxidative stress biomarkers in blood and tissues. The results showed that broilers given feed supplemented with OMWW retentate or permeate had significantly lower protein oxidation and lipid peroxidation levels and higher total antioxidant capacity in plasma and tissues compared to control group. In both OMWW groups, catalase activity in erythrocytes and tissues was significantly increased compared to control group. OMWW retentate administration increased significantly GSH in erythrocytes in broilers with low GSH, although both OMWW products significantly reduced GSH in broilers with high GSH. Thus, it has been demonstrated for the first time that supplementation with OMWW processing residues could be used for enhancing broilers' redox status.

Effects of Heat-oxidized Soy Protein Isolate on Growth Performance and Digestive Function of Broiler Chickens at Early Age

This study was conducted to investigate effects of heat-oxidized soy protein isolate (HSPI) on growth performance, serum biochemical indices, apparent nutrient digestibility and digestive function of broiler chickens. A total of 320 1-day-old Arbor Acres chicks were randomly divided into 4 groups with 8 replicates of 10 birds, receiving diets containing soy protein isolate (SPI, control group) or the same amount of SPI heated in an oven at 100°C for 1, 4, or 8 h, for 21 days, respectively. The results indicated that compared with the control group, body weight gain and feed intake of birds fed diet containing SPI heated for 8 h were significantly lower (p<0.05). Serum urea nitrogen concentration was higher in the broilers fed diet containing SPI heated for 4 or 8 h at d 21 (p<0.05). In contrast, serum glucose content was decreased by HSPI substitution at d 21 (p<0.05). The relative pancreas weight in HSPI groups was higher than that in the control group at d 21 (p<0.05). Meanwhile, the opposite effect was observed for relative weight of anterior intestine and ileum in broilers fed a diet containing SPI heated for 8 h (p<0.05). Birds fed diets containing SPI heated for 4 or 8 h had a decreased lipase activity in anterior intestinal content at d 14 and 21 (p<0.05), respectively. In addition, the same effect was also noted in broilers given diets containing SPI heated for 1 h at d 21 (p<0.05). Similarly, amylase, protease and trypsin activity in anterior intestinal content were lower in broilers fed diets containing SPI heated for 8 h at d 21 (p<0.05). The apparent digestibility of dry matter (DM) from d 8 to 10 and DM, crude protein (CP), and ether extract from d 15 to 17 were lower in broilers fed diets containing SPI heated for 8 h (p<0.05). Besides, birds given diets containing SPI heated for 4 h also exhibited lower CP apparent digestibility from d 15 to 17 (p<0.05). It was concluded that HSPI inclusion can exert a negative influence on the growth performance of broilers, which was likely to result from the simultaneously compromised digestive function.