Thigh Muscle Of Broilers Research Articles

Comparative effects of various dietary selenium sources on growth performance, meat quality, essential trace elements content, and antioxidant capacity in broilers

This study aimed to compare the effects of various dietary selenium (Se) sources (0.5 mg/kg) on performance, meat quality, and antioxidant capacity in broilers as well as essential trace elements concentrations in their blood and tissues. A total of 360 one-day-old male yellow-feathered chickens (37.00 ± 0.17 g) were randomly allocated to 5 diet treatments: the basal diet (CON) and 4 diets supplemented with sodium selenite (SS), selenomethionine (SM), selenium-enriched yeast (SY), and nano-selenium (NS) for 56 d, respectively, with 6 replicates per treatment and 12 chickens per replicate. Dietary Se supplementation did not affect growth performance and carcass characteristics in broilers (P > 0.05). Supplemental SM enhanced the redness in the pectoral muscle compared to CON and NS (P < 0.05). Supplementation of SY and NS improved the concentrations of Se, copper, manganese, and zinc in the serum (P < 0.05). Supplemental SS also elevated the zinc content in the serum (P < 0.05). Broilers fed the SY diet showed increased Se content in the liver and pectoral muscle compared to those fed CON, SM, and NS diets (P < 0.05). Also, SY improved the pectoral muscle Se concentration compared to SS (P < 0.05). Besides, dietary Se supplementation increased the Se content in the thigh muscle (P < 0.05), with SY showing highest Se deposition. Dietary supplementation with SS, SM, and NS improved the activities of total superoxide dismutase and total antioxidant capacity (T-AOC) in the serum (P < 0.05). Supplemental SY also elevated the T-AOC in the serum (P < 0.05). Additionally, SS and SM enhanced the T-AOC in the liver (P < 0.05). In conclusion, supplemental SM affected meat color. Supplementing diets with various Se sources increased antioxidant capacity and Se content in the thigh muscle of broilers, with SY showing a more pronounced deposition efficiency. Besides, diets supplemented with different Se sources had variable effects on the concentrations of essential trace elements in the serum and tissues of broilers.

A multitissue transcriptomic analysis reveals a potential mechanism whereby Brevibacillus laterosporus S62-9 promotes broiler growth

Brevibacillus laterosporus S62-9 has been shown to improve broiler growth performance and immunity. In the present study, we aimed to evaluate the effects of B. laterosporus S62-9 on the immunity and lipid metabolism of broilers by means of transcriptomic analysis. A total of 160 1-day-old broilers were randomly allocated to a S62-9 group, the diet of which was supplemented with 106 CFU/g B. laterosporus S62-9 daily, and a control group, which was not. After 42 d of feeding, the broilers in the S62-9 group had higher body mass (7.2%) and feed conversion ratio (5.19%) than the control group. Supplementation with B. laterosporus S62-9 resulted in lower serum total cholesterol and low-density lipoprotein-cholesterol concentrations and higher high-density lipoprotein-cholesterol concentrations. An analysis of the fatty acid composition of the broiler's thigh muscles revealed that the proportions of the unsaturated fatty acids myristoleic acid (C14:1) and arachidonic acid (C20:1) were higher for birds in the S62-9 group. Transcriptomic analysis also showed an upregulation of immunity-related genes in the S62-9 group. Gene Ontology functional enrichment analysis showed that the mitogen-activated protein kinase pathway was enriched in the liver, the defense response was enriched in the duodenum, and immunoglobulin-related entries were enriched in the jejunum of the S62-9 group. Furthermore, the expression of key genes involved in unsaturated fatty acid synthesis (SCD, encoding stearoyl-CoA desaturase) and fatty acid metabolism (HACD2, encoding 3-hydroxyacyl-CoA dehydratase 2) was upregulated in the liver, and the expression of genes associated with fat biosynthesis and accumulation, such as PLIN1, encoding perilipin 1, and FABP4, encoding fatty acid binding protein 4, was upregulated in the ileum of the birds in the S62-9 group. In summary, supplementation with B. laterosporus S62-9 could improve immune defense and the fatty acid metabolism of broiler chickens, thereby enhancing their disease resistance and promoting growth and development.

Nutritional muscular dystrophy in broiler thigh muscles: pathological analysis of a problem in the field

Objective. This study aims to use histopathologic method to investigate nutritional muscular dystrophy in broilers due to vitamin E deficiency. Materials and methods. Tissue samples taken from 20 dead chicks and total 28 blood samples sent by taking from diseased also eight chicks were analyzed. The amount of vitamin E determined in feed analysis was found to be 5% less than the amount declared to be present in the feed ration. Results. The average amount of α-tocopherol in blood serums was measured as 0.285 µg/g. Plasma calcium and phosphorus levels were found to be high, whereas sodium, potassium, and magnesium levels were found to be normal levels. Histopathologically, nutritional muscular dystrophy was defined in 18 of 20 chicks (90%). In the histopathologic examination of muscular sections, varying degrees of hyaline degenerations, necrosis, mineralization, lipidosis, and mononuclear cell infiltrations were observed. Conclusions. It was determined that when the fat content of the ration was increased, vitamin and mineral levels, particularly vitamin E, changed within the ration content, and the health of the chicks deteriorated, resulting in histopathologic damages in different organ tissues. The study concludes that the poultry farming industry should attach importance to feed management systems for chick’s the proper and healthy feeding.

Dietary Chitosan Oligosaccharide Supplementation Improves Meat Quality by Improving Antioxidant Capacity and Fiber Characteristics in the Thigh Muscle of Broilers.

This study investigated the effects of dietary chitosan oligosaccharide (COS) supplementation on meat quality, antioxidant capacity, and muscle fiber characteristics in the thigh muscle of broilers. The results showed that dietary COS supplementation decreased shear force and increased crude protein content and nutritional value in the thigh muscle, while decreasing the content of C16:0, C18:0, and total saturated fatty acids. Dietary COS supplementation increased free radical scavenging activity, antioxidant enzyme activity, and antioxidant enzyme-related gene expression. Additionally, COS promoted MyHCI while decreasing MyHCIIb mRNA expression levels. The myofiber transformation was associated with upregulated gene expression of CaN, NFATc1, MyoD, and SIRT1. Together, the results of this study demonstrate that dietary COS supplementation improves meat quality, nutritional value, antioxidant capacity, and myofiber transformation to more oxidative muscle fibers in the thigh muscle of broilers when its supplemental level is 400 mg/kg.

Effects of Dietary Supplementation of Chinese Yam Polysaccharide on Carcass Composition, Meat Quality, and Antioxidant Capacity in Broilers.

The study aimed to evaluate the influences of the dietary supplementation of Chinese yam polysaccharide (CYP) on the carcass performance, antioxidant capacity, and meat quality of broilers. Three hundred and sixty healthy 1-day-old broilers with similar body weight (39 ± 1 g, gender balanced) were randomly divided into four groups (control, CYP1, CYP2, and CYP3 groups). In the control group, broilers were fed a basal diet with CYP, and the CYP1, CYP2, and CYP3 groups were fed diets supplemented with 250, 500, and 1000 mg/kg CYP, respectively. There were three replicates in each group, 30 birds in each replicate, and the feeding trial lasted for 48 days. Statistical analysis was performed using SPSS 17.0 (SPSS Inc., Chicago, IL, USA) by one-way analysis of variance. The results showed that compared with the control group, dietary supplementation with 500 mg/kg CYP can improve live weight, half-eviscerated carcass percentage, eviscerated carcass percentage, and thigh muscle percentage. Moreover, dietary supplementation with 500 mg/kg CYP can improve the contents of total antioxidant capacity (T-AOC), total superoxide dismutase (T-SOD), glutathione peroxidase (GPX), and glutathione s-transferase (GST) in serum (p < 0.05). Meanwhile, the mRNA expression levels of nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase 1 (HO-1), quinone oxidoreductase (NQO1), superoxide dismutase 1 (SOD1), glutathione peroxidase 1 (GPX1), and catalase (CAT) in the liver; the mRNA expression levels of HO-1, NQO1, GPX1, and CAT in the breast muscle; and the mRNA expression levels of NQO1, SOD1, and CAT in the thigh muscle of broilers in the CYP2 group were significantly increased (p < 0.05). In addition, the yellowness and shear force of the thigh and breast muscles and the content of malondialdehyde (MDA) in the serum of broilers in the control group were higher than that in the CYP2 groups (p < 0.05). The results demonstrated that the CYP2 group had the best effect on improving meat quality. In conclusion, dietary supplementation with 500 mg/kg CYP can improve the meat quality of broilers by improving carcass quality, meat color, shear force, and antioxidant capacity.

Effects of Chinese yam Polysaccharides on the Muscle Tissues Development-Related Genes Expression in Breast and Thigh Muscle of Broilers.

This experiment was conducted to evaluate the effects of dietary Chinese yam polysaccharides (CYP) on myogenic differentiation 1 (MYOD1), myogenin (MYOG), and myostatin (MSTN) mRNA expression of breast and thigh muscle tissues in broilers. A total of 360 (1-day-old, gender-balanced) crossbred broilers chicks with similar body weight (BW) were randomly distributed into four groups, with three replicates in each group and each replicate included 30 broilers. The feeding trial lasted for 48 days. Experimental broilers were fed 0.00 mg/kg basal diet (control group), 250 mg/kg, 500 mg/kg, and 1000 mg/kg CYP, respectively. The results showed that CYP250 and CYP500 groups had higher thigh muscle percentage (TMP) compared to the control group (p &lt; 0.05). Meanwhile, the expression of MYOD1, MYOG mRNA in breast muscle tissues of CYP500 and CYP1000 groups was higher (p &lt; 0.05), and the expression of MSTN mRNA in thigh muscle of CYP250, CYP500, and CYP1000 groups was lower than that of the control group (p &lt; 0.05). In addition, there was no significant difference in the expression of MYOD1 mRNA in the thigh muscle tissue of each group (p &gt; 0.05). Bivariate correlation analysis showed that the expression levels of MYOD1, MYOG, and MSTN mRNA in the thigh muscle tissue of broiler chickens in the CYP500 group were positively correlated with TMP. However, the expression of MYOG mRNA in thigh muscle tissue of the CYP1000 group was negatively correlated with TMP. In general, this study indicated that appropriate dietary CYP supplementation influenced the growth and development of thigh muscle tissue in broilers by altering TMP and muscle tissue development-related genes expression. Therefore, CYP could be used as a potential feed additive to promote the development of muscle tissues in broilers.

Effects of Feeding Fermented Mulberry Leaf Powder on Growth Performance, Slaughter Performance, and Meat Quality in Chicken Broilers.

Simple SummaryMulberry leaf is widely used in ruminants feeding, such as sheep, beef cattle, and dairy calves. Due to the high content of crude fiber in mature mulberry leaves and branches and the presence of anti-nutritional factors such as tannin, excessive addition will affect the production performance and health of livestock and poultry, and limit its large-scale application in animal production to a certain extent. The disadvantages of woody plants can be improved by microbial fermentation, which can reduce the content of anti-nutritional factors, and increase the content of peptides and amino acids, probiotics, and bioactive components. In this study, Lactobacillus, Saccharomycetes, and Bacillus subtilis were used to make mixed strains to ferment mulberry leaf powder, and different proportions were added to the diet of yellow feathered chicken broilers. The results showed that the addition of fermented mulberry leaf in the diet could improve the digestion and absorption of nutrients, and then improve its growth performance, and increase the contents of inosine monophosphate (IMP), total amino acids, essential amino acids, and delicious amino acids in breast and thigh muscle, and improved polyunsaturated fatty acids and essential fatty acids in breast muscle; this also has a positive effect on improving meat quality.This study was conducted to investigate the effects of feeding fermented mulberry leaf powder (FMLP) on growth performance, slaughter performance, and meat quality of broilers. A total of 360 1-day-old chickens were randomly divided into 5 groups. The control group was fed basal diet (CON), 3% FMLP, 6% FMLP, 9% FMLP, and 3% unfermented mulberry leaf powder. The (MLP) group was fed basal diet supplemented with 3%, 6%, 9% fermented mulberry leaf powder, and 3% MLP, respectively. The experiment lasted for 56 days, with 1–28 days as the starter phase and 29–56 days as the grower phase. The results on the growth performance showed that diets supplemented with 3% FMLP significantly increased the ratio of villus height to crypt depth in the duodenum, jejunum, and ileum of broilers, enhanced the activity of intestinal amylase and digestibility of dry matter and crude protein, improved the average daily gain (ADG), and decreased the feed to gain ratio (F/G) (p < 0.05). Compared with the control group diet, the 3% FMLP group diet significantly increased the breast muscle yield (p < 0.05), reduced the abdominal fat ratio (0.1 < p < 0.05), and improved the slaughter performance of broilers. The 3% MLP group diet increased the shear force of breast muscle (p < 0.05) and thigh muscle of broilers compared to the control group, and adding FMLP could reverse the above results. Additionally, relative to the control group, FMLP supplementation improved the contents of inosine monophosphate (IMP), total amino acids (TAA), essential amino acids (EAA), and delicious amino acids (DAA) in breast and thigh muscle, and improved polyunsaturated fatty acids (PUFA) and essential fatty acids (EFA) in breast muscle; the 6% and 9% FMLP groups showed preferably such effects (p < 0.05). In conclusion, dietary supplementation of FMLP can improve the digestion and absorption of nutrients, and then improve the growth performance of broilers; it also has a positive effect on improving slaughter performance and meat quality.

Impact of Dietary Humic Substances Supplementation on Selected Minerals in Muscles of Broiler Chickens

Abstract In this study, we assessed the effect of humic substances on the changes of some mineral (Ca, Mg, Cu and Zn) content in the thigh and breast muscle of broilers. Group 1 (G1) was supplemented with 0.7 % Humac Natur Mycosorb (HNMy), and G2 with 0.3 % HNMy. The control group (GC) received a basal diet without any supplements. In the breast muscle of broilers from the group G1 we found a statistically significantly higher (P &lt; 0.05) Ca content and significantly reduced (P &lt; 0.05) in the thigh muscle Ca content from the group G2 compared to the control group (GC). A statistically significant increase in Mg content (P &lt; 0.05) was analyzed in breast muscles in the group G1 and also significant reduction (P ≤ 0.01) in Cu in the breast and thigh muscles was found in the group G1 and in the breast muscle from the group G2 compared to the GC. Significantly lower content of Zn (P ≤ 0.05) was found in the breast and thigh muscles of broilers in the group G2 and strong positive correlation (r = 0.9093) were observed between Ca in breast muscle from the group G2 and Ca in thigh muscle from the control group. A negative correlation (r = –0.7656) was shown for Mg between thigh muscle from the group G2 and Ca in thigh muscle from the GC. A strong negative correlation was confirmed (r = –0.9221) for Zn content in breast muscles between groups G2 and G1. The high positive correlation for Zn was occurred between breast muscle from the control group and thigh muscle from the group G1 (r = 0.9786).

Effect of stocking density on performance, meat quality and cecal bacterial communities of yellow feather broilers

Totally, 315 42-day-old male Xueshan chickens were allocated into 3 caging densities, 14, 21 and 28 birds/m2. Each treatment was represented by 5 replicates. The body weight (BW), slaughter performance, meat quality, behavioral assessment, and the cecal microorganisms were detected at the market age. The results showed that the BW of broilers in the low- and medium-density groups was significantly higher (p < 0.05) than that of the high-density group from the age of 10 weeks. Only the feather quality of the broilers in the low-density group improved significantly (p < 0.05) compared with those of the other two groups. And, the abdominal fat percentage and the fat content of thigh muscle of broilers in the low- and medium-density groups were higher (p < 0.05) than those in the high-density group. No significant difference (p > 0.05) was noted in the other traits. The abundance of some microbial like Akkermansiaceae, Lactobacillaceae and Faecalibacterium may be correlated with the BW and fat content of broilers. The findings of this study suggest that increasing the stocking density decreased the final BW, fat content and the feather quality, whereas no evidence was found that stocking density caused changes in other parameters.

Effect of DL-Methionine Supplementation on Tissue and Plasma Antioxidant Status and Concentrations of Oxidation Products of Cholesterol and Phytosterols in Heat-Processed Thigh Muscle of Broilers.

Simple SummaryThe occurrence of oxidative stress is a general problem in high-yielding farm animals. Oxidative stress not only affects animal health, but free radicals generated under oxidative stress conditions can also promote the oxidation of lipids in animal products which are detrimental for the consumer, such as lipid oxidation products. Therefore, prevention of oxidative stress by improving the antioxidant system has high priority in farm animal management. Methionine (Met) is a precursor of glutathione, one of the major antioxidants in the body. Therefore, we investigated the hypothesis that feeding diets with an excess of Met in relation to the requirement for optimum growth improves the antioxidant status by enhancing the formation of glutathione in broilers. We observed that broilers fed diets with an excess of Met had higher concentrations of glutathione in liver and thigh muscle, indicative of an improved antioxidant status, and moreover had lower concentrations of cholesterol oxidation products in heat-processed thigh muscle, in comparison to broilers of the control group. This effect is favorable with respect to animal health and quality of broiler meat.In this study, the hypothesis that supplementation with methionine (Met) as DL-Met (DLM) in excess of the National Research Council (NRC) recommendations improves the antioxidant system in broilers was investigated. Day-old male Cobb-500 broilers (n = 72) were divided into three groups which were fed a control diet or diets supplemented with two levels of DLM in which the concentrations of Met + Cys exceeded the recommendations of NRC by 15–20% (group DLM 1) or 30–40% (group DLM 2), respectively. The three groups of broilers did not show differences in body weight gains, feed intake, and feed conversion ratio. However, broilers of groups DLM 1 and DLM 2 had higher concentrations of glutathione (GSH) in liver and thigh muscle and lower concentrations of cholesterol oxidation products (COPs) in heat-processed thigh muscle than broilers of the control group. Concentrations of several oxidation products of phytosterols in heat-processed thigh muscle were also reduced in groups DLM 1 and DLM 2; however, the concentration of total oxidation products of phytosterols was not different between the three groups. The study shows that DLM supplementation improved the antioxidant status due to an increased formation of GSH and reduced the formation of COPs during heat-processing in thigh muscle.

Supplemental carbohydrase enzyme and methionine in broilers fed flaxseed: effects on growth performance, nutrient retention, muscle lipids, and jejunal morphology

The present study investigated the effect of carbohydrase enzyme, methionine ( Met ) (100% above Cobb 500 requirement level), or their combination on growth performance, carcass yield, total tract retention ( TTR ) of DM, CP, fatty acid ( FA ), muscle FA composition, lipid peroxidation products, and jejunum histomorphology in broiler chickens fed 10% flaxseed-containing diets. One hundred and twenty (n = 120) day-old Cobb chicks were fed corn-soybean meal–based diet containing 0% flaxseed (control), 10% whole flaxseed (diet 1), diet 1 + 0.05% carbohydrase enzyme (diet 2), diet 1 + 100% more Cobb 500 Met requirement (diet 3), and diet 1 + 0.05% carbohydrase enzyme + 100% more Cobb 500 Met requirement (diet 4) for 42 d. The data were analyzed by ANOVA with 5 treatments with 4 replications in a completely randomized design. At day 42, BW gain was the highest in control when compared to flaxseed-containing diets ( P < 0.05). Dry matter TTR was higher in diet 3 and diet 4 than that in diet 1 and diet 2 ( P < 0.05), and CP TTR was highest in diet 3 compared with that in diet 1 and diet 2 ( P < 0.05). Supplementing Met increased linoleic and α-linolenic acid TTR in birds fed flaxseed ( P < 0.05). Total and long-chain (≥20C) n-3 FA was higher in the thigh muscle of broilers fed diet 3 and diet 4 than in those fed diet 1, diet 2, and control ( P < 0.05). Lipid oxidation products in the thigh muscle was the highest in birds fed diet 4 ( P < 0.05). Jejunal villous height, villous perimeter, and villous surface area were highest in birds fed diet 1 ( P < 0.05). In conclusion, supplementing Met, or its combination with carbohydrase enzyme, increased DM, CP, and essential FA TTR and thigh muscle n-3 FA in broilers fed flaxseed. However, supplementing Met or its combination reduced BW gain and negatively affected jejunal morphology in broilers fed flaxseed.

Effect of chestnut wood extract on performance, meat quality, antioxidant status, immune function, and cholesterol metabolism in broilers

Plant extracts have been proved as natural antioxidants resources as well as alternative feed additives in livestock and poultry species. Chestnut wood extract (CWE) as a source of hydrolysable tannic acid was used to evaluate the growth performance, nutrient retention, meat quality, antioxidant status, and immune function of broilers. A total of 168, day-old Arbor Acre male broilers (weight 46.59 ± 0.44 g) were randomly divided to 3 treatments, 7 replicate pens per treatment, 8 broilers per pen. The treatments contain a control diet, CON (corn-soybean meal basal diet); an antibiotic diet, CTC (basal diet + 75 mg/kg chlortetracycline); and chestnut wood extract diet, CWE (basal diet + 1,000 mg/kg chestnut tannins). At the finisher phase, final body weight was higher (P < 0.05) in CWE supplemented diet than in CON. Average daily body weight gain was higher (P < 0.05) and feed gain ratio was lower (P < 0.05) in broilers fed CWE than in those fed CON at the finisher phase. Crude protein digestibility was higher (P < 0.05) in broilers offered CWE than that in broilers fed CON and CTC diets. Breast muscle pH value at 24 h (pH24 h) was higher (P < 0.05) in broilers fed CWE than that in those fed CON and CTC diets. The bursa weight was higher (P < 0.05) in broilers offered CWE than that in those fed CON and CTC. Total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) values were higher (P < 0.05) in both breast muscle and thigh muscle of broilers offered CWE supplemented diet than those in broilers fed CON and CTC diets. Similarly, broilers offered with CWE diets showed higher (P < 0.05) T-AOC, GSH-PX, and SOD value in serum than those fed CON and CTC diets. Serum concentration of IgG was higher (P < 0.05) in broilers offered with CWE diets than that in those fed CON and CTC diets. Total cholesterol, low-density lipoprotein cholesterol, and urea-N concentration were lower (P < 0.05) in broilers offered CWE diet than those in broilers fed CON and CTC diets. It was recommended to supply CWE at the 1,000 mg/kg level for improving antioxidant status, cholesterol metabolism, and growth performance without affecting normal meat quality in broilers.

Effect of pine (Pinus densiflora) needle and Korean mistletoe (Viscum album var. coloratum) powder on male broiler chicken growth, serum cholesterol profiles, and meat quality

Pine (Pinus densiflora) needle leaf (PNL) and Korean mistletoe (KM) (Viscum album var. coloratum) were compared as dietary supplements for male broiler chickens, and their effects on broiler growth, serum cholesterol profiles, and meat quality were investigated.A total of 240 one-day-old male broilers (40~45 g/body weight) were randomly assigned to 4 dietary groups (control, 0.5% PNL, 1% PNL, and 1% KM) of 60 birds each (3 replicates per group) in a completely randomized design. PNL and KM dietary supplements did not affect broiler growth performance, but mortality was reduced in the 1% KM-treated group. Serum cholesterol profiles indicated that total cholesterol and low-density lipoprotein cholesterol level (LDLC) decreased significantly while high-density lipoprotein cholesterol (HDLC) level increased in treatment groups compared to levels in the control group. Decrease in lightness and redness color values in thigh meat of broilers fed PNL and KM powder were observed. However, no significant differences were observed among the groups with regard to triglyceride and glucose levels, pH, and yellowness of the meat. In conclusion, 1% KM dietary supplement can reduce mortality, which may be due to the immune-regulating effects of KM, as well, it can reduce lipid oxidation and improve meat color stability via an antioxidant action in broiler thigh muscles.

Glutamine improves heat stress–induced oxidative damage in the broiler thigh muscle by activating the nuclear factor erythroid 2–related 2/Kelch-like ECH-associated protein 1 signaling pathway

The aim of the present study was to evaluate the effect of glutamine (Gln) on modulating heat stress–induced oxidative damage in the broiler thigh muscle through nuclear factor erythroid 2–related 2/Kelch-like ECH-associated protein 1 (Nrf2-Keap1) pathway. Three-hundred 22-day-old Arbor Acres broilers were reallocated into 5 groups: a control group (24 °C) fed with basal diet and 4 heat stress (HS) groups (34 °C for 8 h/D) fed with basal diet containing 0, 0.5, 1.0, and 1.5% Gln. This experiment lasted 21 D. Heat stress decreased (P < 0.05) pH, redness, and Gln levels, and increased (P < 0.05) luminance, water loss rate, and cooking loss (CL) values of the thigh meat. Compared with the HS group, supplementation with 1.5% Gln increased (P < 0.05) pH, redness, and Gln levels, but decreased (P < 0.05) luminance and CL values in the thigh meat. There were significant decreases (P < 0.05) in glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), and Nrf2 levels, but significant increases (P < 0.05) in the malondialdehyde (MDA) and Keap1 levels of the thigh muscle after HS treatment. Compared with the HS group, supplementation with 1.0, and 1.5% Gln decreased (P < 0.05) MDA and Keap1 levels; supplementation with 1.5% Gln increased (P < 0.05) GSH, GSH-Px, T-AOC, CAT, SOD, and Nrf2 levels in the thigh muscle of heat-stressed broilers. Furthermore, HS decreased (P < 0.05) Nrf2, SOD, CAT, and GSH-Px mRNA expression levels, but increased (P < 0.05) Keap1 mRNA level in the thigh muscle of broiler. Dietary supplementation with 1.5% Gln increased (P < 0.05) Nrf2, GSH-Px, CAT, and SOD mRNA expression levels, but decreased (P < 0.05) Keap1 mRNA level in the thigh muscle of heat-stressed broilers. In conclusion, dietary Gln improved the resistance of heat-stressed broiler muscles to oxidative damage possibly through reversing the muscle Gln level and inducing the expression of the Nrf2-Keap1 pathway.

Evaluation of pre‐slaughter low‐current/high‐frequency electrical stunning on lipid oxidative stability, antioxidant enzyme activity and gene expression of mitogen‐activated protein kinase/nuclear factor erythroid 2‐related factor 2 (MAPK/Nrf2) signalling pathway in thigh muscle of broilers

SummaryThis study was aimed to evaluate the effects of pre‐slaughter low‐current/high‐frequency (LH) electrical stunning (ES) on lipid oxidative stability, antioxidant enzyme activity and gene expression of mitogen‐activated protein kinase/nuclear factor erythroid 2‐related factor 2 (MAPK/Nrf2) signalling pathway in thigh muscle of broilers. Eighteen birds were randomly allocated to the following three treatments with six replicates per treatment and one bird per replicate: without stunning (control); water‐bath ES with sinusoidal alternating LH (86 mA, 1000 Hz, LHES) or high current/low frequency (HL) (130 mA, 60 Hz, HLES). Stunning methods did not affect malondialdehyde level (d 0 ~ d 9) or antioxidant enzymes’ activity at d 0 ~ d 2. LHES enhanced glutathione S‐transferase activity at d 3 and gene expression of MAPKs and Nrf2 compared with HLES. In conclusion, LHES enhanced gene expression of MAPK/Nrf2 pathway, whereas had no superiority over HLES in lipid oxidative stability (4 °C, 9 days) of thigh muscle in broilers.

Effects of zinc oxide nanoparticles on growth performance and concentrations of malondialdehyde, zinc in tissues, and corticosterone in broiler chickens under heat stress conditions.

The use of nanominerals, such as nano-zinc, represents a promising and emerging technology in the animal farming industry. Due to the small particle size and bioavailability of nano-zinc, it can be easily assimilated in the digestive system, thereby reducing excretion and environmental pollution. The present study was conducted to assess the effects of zinc oxide nanoparticles (ZnONPs) on the growth performance, zinc (Zn) concentration in edible tissues, thiobarbituric acid reactive substance, and corticosterone concentrations in broilers reared under normal or heat stress environmental conditions. The experiment was performed with a completely randomized design based on a 4 × 2 factorial arrangement consisting of 4 diets (basal diet + 60mg/kg conventional zinc oxide as control diet; basal diet + 40mg/kg of ZnONPs; basal diet + 60mg/kg of ZnONPs; and basal diet + 100mg/kg of ZnONPs) and 2 environmental conditions (normal and heat stress). On day 22, birds from each dietary group were divided equally to normal temperature (23 ± 1°C throughout) or heat stress conditions (34 ± 1°C daily for 6h from 10:00 am until 4:00 pm). From 1 to 42 D of age, the broiler chickens fed 100mg/kg ZnONPs exhibited lower feed intake and feed conversion ratio than the control. The accumulation of Zn in the liver of broilers was significantly higher among all treatment groups compared to breast and thigh muscle tissues regardless of the temperature conditions. At 40 and 60mg/kg ZnONPs, the malondialdehyde content increased in thigh muscle of broilers at 7 D postmortem, indicating that ZnONPs potentially inhibited the antioxidant system in muscle tissues. The control and ZnONPs at 40mg/kg and 60mg/kg led to low serum corticosterone levels that may be attributed to the antioxidant and antistress properties of Zn. Taken together, although supplementation with ZnONPs at 40mg/kg and 60mg/kg alleviated the negative results of heat stress, further research is needed to determine the optimal level of dietary ZnONPs supplementation.

Collapse of the endogenous antioxidant enzymes in post-mortem broiler thigh muscles triggers oxidative stress and impairs water-holding capacity.

This study was conducted to investigate the effect of the collapse of the endogenous antioxidant enzymes, namely, catalase (CAT), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) in post-mortem (PM) chicken thigh muscles on the extent of lipid and protein oxidation and the functionality of the muscle in terms of water-holding. To fulfil this objective, the samples were divided into two treatments: one group of muscles (n = 8) was subjected to delay cooling (DC) (at ~ 37°C for 200min PM) and then stored at 4°C for 24h. The second group (n = 8) was subjected to a normal cooling (NC): samples were immediately chilled at 4°C for 24h. DC samples presented a decrease in 16% of CAT, 25% GSH-Px and 20% SOD activity in relation to NC. Consistently, an increase of 36% of total carbonyl, 15% of Schiff bases and 27% of TBA-RS and 14% of tryptophan depletion was observed in DC samples, as compared to NC. The results suggested that DC challenged muscles to struggle against oxidative reactions, consuming endogenous antioxidant defenses and causing protein and lipid oxidation which in turn affect the quality and safety of chicken meat. These results emphasize the role of PM oxidative stress on chicken quality and safety. Antioxidant strategies like fast cooling may be combined with others (dietary antioxidants) to preserve chicken quality against oxidative stress.

In ovo feeding of creatine pyruvate alters energy metabolism in muscle of embryos and post-hatch broilers.

ObjectiveThis study was conducted to investigate the effects of in ovo feeding (IOF) of creatine pyruvate (CrPyr) on the energy metabolism in thigh muscle of embryos and neonatal broilers.MethodsA total of 960 eggs were randomly assigned to three treatments: i) non-injected control group, ii) saline group injected with 0.6 mL of physiological saline (0.75%), and iii) CrPyr group injected with 0.6 mL of physiological saline (0.75%) containing 12 mg CrPyr/egg on 17.5 d of incubation. After hatching, 120 male chicks (close to the average body weight of the pooled group) in each group were randomly assigned to eight replications. The feeding experiment lasted 7 days.ResultsThe results showed that IOF of CrPyr increased glucose concentrations in the thigh muscle of broilers on 2 d after injection (p<0.05). Compared with the control and saline groups, the concentration of creatine in CrPyr group was increased on 2 d after injection and the day of hatch (p<0.05). Moreover, IOF of CrPyr increased the creatine kinase activity at hatch and increased the activities of hexokinase and pyruvate kinase on 2 d after injection and the day of hatch (p<0.05). Chicks in CrPyr group showed higher mRNA expressions of glucose transporter 3 (GLUT3) and GLUT8 on the day of hatch (p<0.05).ConclusionThese results demonstrated that IOF of CrPyr was beneficial to enhance muscle energy reserves of embryos and hatchlings.

Effects of cyclic heat stress on the phenotypic response, meat quality and muscle glycolysis of breasts and thighs of yellow-feather broilers

An experiment was conducted to evaluate the effects of cyclic heat stress on phenotypic response, meat quality and muscle glycolysis of broiler. One hundred and eighty 35-day-old male Xueshan broilers with similar BW were randomly selected and exposed to either thermal neutral (TN; 23 °C, 55–60% RH, n = 6) or heat stress conditions (CHS; cyclic temperatures of 35 °C from 10:00 to 18:00, 32 °C from 18:00 to 20:00, 28 °C from 20:00 to 08:00, and 32 °C from 08:00 to 10:00 at 40–45% RH, n = 6) for 7 days. Relative to broilers under thermoneutral conditions, broilers subjected to cyclic heat stress had an overall increase in rectal temperature and respiration rate (p < .001, p < .001, respectively), and a reduced body weight, average daily gain, average feed intake and feed conversion ratio (p = .001, p < .001, p < .001, p = .002, respectively). A higher L* value was obtained from both the breast and thigh muscle of broilers under high temperatures (p = .022 and p = .009, respectively). Furthermore, the thigh muscle of broilers exposed to high temperatures showed a higher hexokinase activity than that of broilers exposed to thermal neutral conditions (p = .014). The results indicate that cyclic heat stress significantly lowers Xueshan broiler production performance and meat quality but has no significant effect on the chemical composition and glycolytic process of the meat.HighlightsCyclic heat stress decreases body weight, average daily weight gain, average feed intake and feed conversion ratio in yellow-feather broilers.Cyclic heat stress decreases the weight, physicochemical characteristics of breast and thigh meat in yellow-feather broilers.Cyclic heat stress increases hexokinase activity to mobilize more glucose to supply the energy for aerobic metabolism in yellow-feather broilers.

Influence of the addition of post-extraction rapeseed meal on the sensoric quality of poultry meat

Complete feed mixtures, very often enriched by the addition of various probiotic preparations, oils, extract, essential oils, mouldings, pollards etc., that are often added as a replacement for animal meals, antibiotic preparations, coccidiostats respectively, are used for feeding of chickens. In addition to the positive effects of these supplements, the final quality of meat may be adversely affected by the accumulation of certain components. The aim of the work was to monitor the influence of adding post -extraction rapeseed meal (PRM) to a broiler feed mixture on the sensory quality of breast and thigh muscle. The experience includes two hybrid combinations of broilers, ROSS 308 and COBB 500. Samples of breast and thigh muscle of broilers fed by a feed mixture with the addition of 10% post -extraction rapeseed meal were compared, using sensory analysis, with a control sample where the broilers were fed by a standard feed mixture without the addition of PRM. It has been found that the addition of post -extraction rapeseed meal to the broilers' feed mixture had a positive effect (p &lt;0.05) on the sensory quality of hybrid ROSS 308, both on the breast and thigh muscle. For COBB 500 hybrid, the quality of both breath and thigh muscle has not been shown to be significantly affected. The addition of 10% PRM affected positively especially the texture properties of ROSS 308, hybrid breast muscle, whereas they were deteriorated in COBB 500. In sensory evaluation, by adding 10% of PRM to the feed mixture, thigh muscle was affected less than breath muscle. Adding 10% PRM to the feed has almost no effect on descriptors of the intensity and pleasantness of smell and the intensity and pleasantness of taste, both in the negative and positive sense, both in breath and thigh muscle. The evaluation of the overall quality of both breath and thigh muscle has turned out more positive for ROSS 308 hybrid, although only slightly. The addition of rapeseed extracted meal to feed hybrids ROSS COBB 308 and 500 had no significant effect on the sensory quality of breast and thigh muscle.