Resveratrol beneficially affects meat quality of heat‐stressed broilers which is associated with changes in muscle antioxidant status

This study was conducted to evaluate the effect of dietary resveratrol (Res) supplementation on serum parameters, meat quality and muscle antioxidant status of broilers under heat stress (HS). A total of 270 21‐day‐old male Cobb broilers were randomly assigned to three treatment groups with six replicates of 15 birds each. The three treatment groups were as follows: the control group, in which birds were reared at 22 ± 1°C, and the HS and HS + Res (400 mg/kg) groups, in which birds were reared at 33 ± 1°C for 10 h (08.00–18.00 h) and 22 ± 1°C for the rest of the time. Compared with birds in the control group, birds in the HS group exhibited increased serum corticosterone (CORT) and triacylglycerol contents, L*, drip loss and muscle malondialdehyde content, and decreased serum glucose content, pH_24 h, muscle total antioxidant capacity (T‐AOC), catalase (CAT) and glutathione peroxidase (GSH‐PX) activities (P < 0.05). Compared with birds in the HS group, birds in HS + Res group exhibited increased serum glucose content, a*, pH_24 h, muscle T‐AOC and CAT activities, and decreased serum CORT and triacylglycerol contents, L*_24 h, drip loss and muscle malondialdehyde content (P < 0.05). In conclusion, Res beneficially protects against HS‐impaired meat quality of broilers through regulating muscle antioxidant status.     

Effects of rearing system on meat quality,fatty acid and amino acid profiles of Hu lambs

To determine the effects of early rearing system on meat quality traits, fatty acid and amino acid profiles of meat, 48 Hu lambs were selected and randomly divided into four treatments: control lambs were ewe‐reared from birth to 60 days of age (ER), while treatment lambs were segregated from their dams at 10, 20 and 30 days of age, then artificially reared with milk replacer until 60 days of age (EW10, EW20 and EW30, respectively). All lambs had no access to the milk replacer or their dams from 61 to 90 days. Creep feed was supplied ad libitum to all lambs from 15 to 90 days of age. Artificially reared lambs (EW10, EW20 and EW30) had higher (p < .05) creep feed intake, average daily gain, slaughter weight, hot carcass weight, meat ether extract content, bright meat color (lightness and yellowness) than ewe‐reared lambs. The content of unsaturated fatty acids and monounsaturated fatty acids in EW10 and EW20 were greater (p < .05) than that in ER, whereas the proportions of saturated fatty acids in EW10 and EW20 were lower than that in ER (p < .05). The percentages of C18:0, C18:2, C18:3 and the ratio of polyunsaturated fatty acids and saturated fatty acids of artificially reared lambs were greater than ewe‐reared lambs (p < .05). The meat proportions of leucine, alanine and proline were higher (p < .05) in artificially reared lambs than ewe‐reared ones. Finally, the artificially reared system increased meat production and changed the fatty acid and amino acid profiles of meat, and it would be appropriate to rear Hu lambs artificially from 10 days with milk replacer.     

Effects of dietary water‐soaked barley on amino acid digestibility,growth performance,pork quality and Longissimus dorsi muscle fatty acid profiles in pigs

Two experiments were conducted to assess the feeding value of water‐soaked barley (WB) as a replacement for dehulled barley (DB) in pigs. In experiment (Exp.) 1, eight barrows (body weight = 30.56 ± 0.78 kg) were fitted with a T‐cannula and allotted to a duplicated 4 × 4 Latin square design: WB10, 100g/kg WB; WB20, 200 g/kg WB; DB10, 100 g/kg DB; and DB20, 200 g/kg DB. In Exp. 2, 80 barrows (body weight = 70.56 ± 1.29 kg) were used in a 56‐day experiment: (i) WB15, 150 g/kg WB; (ii) WBD10, 100 g/kg WB and 50 g/kg DB; (iii) WBD5, 50 g/kg WB and 100 g/kg DB; and (iv) DB15, 150 g/kg DB. In Exp. 1, the apparent ileal digestibilities of total essential amino acids were higher (P < 0.05) in WB10 treatment than DB20. For Exp.2, the WB15 and WBD10 had higher pH and lower cooking loss (P < 0.05) than other two treatments. The WB15 treatment decreased (P < 0.05) the contents of palmitic acid (C16:0) in Longissimus dorsi muscle than WBD5 and DB15 treatments. In conclusion, it is suggested that water‐soaked barley improved some amino acid digestibility and the cooking loss and moderate fatty acid profiles in Longissimus dorsi muscle.     

Carcass traits,meat quality,antioxidant status and antioxidant gene expression in muscle and liver of Hu lambs fed perilla seed

The effects of perilla (Perilla frutescens L.) seed on carcass traits, meat quality, antioxidant status and antioxidant gene expression in the liver and muscle of Hu lambs were investigated in this study. Sixty Hu lambs (23.02 ± 1.36 kg) were randomly divided into four experimental groups receiving diets containing 0%, 5%, 10% or 15% perilla seed (CD, 5%PFSD, 10%PFSD and 15%PFSD, respectively). The addition of perilla seed had no significant impacts on carcass traits (p > .05). There were no differences in pH, meat colour, drip loss, cooking loss or shear force among the four treatments (p > .05). Addition of perilla seed increased (p < .05) deposition of intramuscular lipids but had no effect on other chemical components in the longissimus dorsi (LD) (p > .05). The 15%PFSD diet decreased the total antioxidant capacity (T‐AOC) and malondialdehyde (MDA) content in the liver (p < .05 for both) but increased the activity of these antioxidant enzymes in LD (p < .05 for both). Compared to CD, addition of perilla seed increased superoxide dismutase (SOD) and glutathione peroxidase (GPX) expression in the liver and LD (p < .05 for all). These results indicate that perilla seed supplementation in lambs’ diets can increase deposition of intramuscular lipids and improve muscular oxidative status and meat quality.     

Effects of dietary supplementation with carnosine on meat quality and antioxidant capacity in broiler chickens

1. This study aimed to investigate the effects of carnosine supplementation on meat quality, antioxidant capacity and lipid peroxidation status in broiler chickens.

2. A total of 256 1-d-old male Arbor Acres broilers were randomly assigned to 4 treatments consisting of 8 replicates of 8 chickens each. The birds were supplied with 4 different diets: a basal diet or a basal diet supplemented with 100, 200 or 400 mg/kg carnosine, respectively. The whole experiment lasted 42 d.

3. The results showed that dietary supplementation with carnosine linearly increased the values of pH_45 min and redness and reduced drip loss of breast meat. Dietary carnosine increased the activity of antioxidant enzymes in liver, serum and breast meat and decreased the contents of lipid peroxides at 21 and 42 d of age.

4. These findings indicated that dietary supplementation with carnosine was beneficial to enhance meat quality, antioxidant capacity and decrease lipid peroxidation status of breast meat.     

复方黄芪颗粒对肉鸡肉品质的影响

试验旨在探究复方黄芪颗粒对肉鸡肉品质的影响.采用罗斯肉仔鸡进行饲喂试验,试验组分别添加0.87％、1.74％、3.48％复方黄芪颗粒,试验期42 d.结果 显示,肉质含水量均在71％～78％之间,复方黄芪颗粒给药组含水量均高于对照组.胸肌和腿肌的pH2h值和pH24h值均在优质鸡pH值范围内,给药组pH值均大于对照组....     

Effects of guanidinoacetic acid on growth performance,creatine metabolism and plasma amino acid profile in broilers

The objective of this study was to assess the effects of guanidinoacetic acid (GAA) on growth performance, creatine deposition and blood amino acid (AA) profile on broiler chickens. In Exp. 1, a total of 540 one‐day‐old Arbor Acres male broilers (average initial body weight, 45.23 ± 0.35 g) were divided randomly into five treatments with six replicates of 18 chicks each. Broilers were fed corn–soybean meal‐basal diets supplemented with 0, 600, 800, 1,000 or 1,200 mg/kg GAA for 42 days respectively. Results showed that dietary GAA inclusion increased average daily gain (ADG) and improved gain‐to‐feed ratio (G:F) from 1 to 42 days (p < 0.01). However, average daily feed intake was unaffected by dietary supplementation of GAA. As GAA inclusion increased, the contents of creatine in plasma and kidney were increased (linear, p < 0.01), while the contents of GAA and creatine in liver were decreased (linear, p < 0.01). Similarly, GAA supplementation was inversely related to concentrations of most essential AA in plasma. In Exp. 2, a total of 432 one‐day‐old Arbor Acres male broilers (average initial body weight, 39.78 ± 0.58 g) were divided randomly into four treatments with six replicates of 18 chicks each. Birds were fed a corn–soybean meal‐basal diet supplemented with 0, 200, 400 or 600 mg/kg GAA for 42 days respectively. Dietary inclusion of 600 mg/kg GAA significantly increased ADG and G:F of broilers (p < 0.05). In conclusion, dietary supplementation of 600–1,200 mg/kg GAA can effectively improve the growth performance in broiler chickens by affecting creatine metabolism and utilization efficiency of essential AA, and 600 mg/kg GAA is the minimum dose for improving performance.     

The effect of dietary turmeric on antioxidant properties of thigh meat in broiler chickens after slaughter

Two hundred and fifty‐day‐old male broiler chicks (Ross 308) were used to investigate the dietary supplementation effects of different levels of 0.0 turmeric rhizome powder (TRP) (free TRP, F.TRP), 0.25 (low TRP, L.TRP), 0.5 (medium TRP, M.TRP) and 0.75% TRP (high TRP, H.TRP) or 50 mg/kg vitamin E (VE) on antioxidant properties of thigh meat in broiler chickens after slaughter. No effect of treatment was observed for the activities of glutathione peroxidase (GPX) and superoxide dismutase (SOD) and total antioxidant status (TAS) in thigh meat (P > 0.05) but all were reduced over time (P < 0.0001). A significant treatment*time interaction was observed for thigh meat GPX activity (P = 0.02). Significant effects of treatment and time were observed for malondialdehyde (MDA) content (P < 0.05). There was no significant difference between the treatments for thigh meat MDA content at slaughter (P > 0.05). Three days after refrigerator storage, MDA content in thigh meat of M.TRP birds was lower than that of F.TRP birds (P < 0.05). Both the M.TRP and VE birds showed a lower MDA content in thigh meat as compared with F.TRP birds 7 days after storage (P < 0.05). In conclusion, dietary consumption of 5 mg/kg TRP can increases the thigh meat shelf‐life storage and quality in broiler chickens after slaughter.     

Enterococcus faecium NCIMB 10415 supplementation improves the meat quality and antioxidant capacity of muscle of broilers

The present study was conducted to investigate the effects of Enterococcus faecium (E. faecium) on the meat quality and antioxidant capacity of muscle in broilers. A total of 600 Arbor Acre broiler chickens (1‐day‐old, male) were randomly divided into five treatments with six replicates (20 chickens per replicate) for each treatment. The five treatments were the control treatment (CON, basal diet), antibiotic treatment (ANT, basal diet supplemented with 0.1% chlortetracycline) and E. faecium‐supplemented treatments (LEF, MEF and HEF, basal diet supplemented with 50, 100 and 200 mg/kg of E. faecium respectively). The experiment lasted 42 days in two periods of 21 days. Results showed that there were no differences in breast meat quality among different treatments (p > 0.05). Compared with the CON and ANT treatments, the yellowness of thigh meat in E. faecium‐supplemented treatments was significantly increased (p < 0.05); the shear force of thigh meat in the LEF and MEF treatments was lower than that of the CON treatment (p < 0.05). In addition, the concentration of the inosine monophosphate (IMP) in the breast and thigh meat of the MEF treatment was significantly higher than that of the other treatments (p < 0.05). At 21 days, the total antioxidant capability (T‐AOC) level and glutathione peroxidase (GSH‐Px) activity of breast meat and superoxide dismutase (SOD) in the thigh meat of the MEF treatment were greatly increased (p < 0.05). At 42 days of age, the catalase (CAT), GSH‐Px and T‐AOC activities in the breast meat of the MEF treatment were increased (p < 0.05) and the CAT activity of thigh meat in the LEF and MEF treatments was increased (p < 0.05). In conclusion, E. faecium supplementation increased the meat quality of the thigh muscle, increased the IMP content and the activities of CAT, SOD, T‐AOC, and GSH‐Px of muscle in broilers. Supplementation with 100 mg/kg E. faecium had the greatest effects.     

Effects of pre‐slaughter showering and ventilation on stress,meat quality and metabolite concentrations of broilers in summer

Effects of pre‐slaughter showering and ventilation on stress, meat quality and energy metabolism of broilers in summer were investigated. After transport, 84 Arbor Acres broilers were randomly divided into four treatment groups: (i) control group without ventilation and showering (C); (ii) 10 min ventilation without showering (VWS); (iii) 10 min showering without ventilation (SWV); (iv) 5 min showering and then 5 min ventilation (SV). Compared with the control group, plasma lactate dehydrogenase and creatine kinase activities in the other three treatment groups were (P < 0.05) lower; however, the plasma glucose level did not show any significant changes among all the groups. The breast meat in the SV group had significantly (P < 0.05) higher pH_u, glycogen content, lower L*, ΔpH, drip loss, cook loss, R‐value and lactate content than the control group; however, there was no significant difference in shear force values among all the groups. In conclusion, this study indicated broilers in the SV group showed a lower stress level and greater meat quality, which suggest that showering and ventilation after transportation may be a good measure to relieve stress caused by transport under high temperature and improve the meat quality of broilers.     

Effects of dietary supplementation with betaine on muscle growth,muscle amino acid contents and meat quality in Cherry Valley ducks

The effects of dietary betaine supplementation on growth performance, carcass characteristics, muscle amino acid contents, meat quality, antioxidant capacity, myogenic gene expression and mechanistic target of rapamycin (mTOR) signalling pathway in Cherry Valley ducks were evaluated. A total of 720 1‐day‐old Cherry Valley ducks were randomly distributed into four groups with six replicates of 30 birds for a 42‐day feeding trial. Ducks were fed a basal diet supplemented with 0 (control), 250, 500 or 1,000 mg/kg betaine, respectively. Growth performance was not affected by betaine. Incremental levels of betaine linearly (p < 0.05) increased the breast muscle yield and linearly (p < 0.05) decreased the subcutaneous fat thickness and the abdominal fat yield. The contents of methionine, serine, glycine, glutamate and total non‐essential amino acid in breast muscle were linearly (p < 0.05) increased by betaine supplementation. With increasing betaine levels, the drip loss and the content of malondialdehyde (MDA) were linearly (p < 0.05) decreased, and the redness of meat (linear p < 0.05), the activities of catalase (CAT) (linear p < 0.05) and total superoxide dismutase (T‐SOD) (linear p < 0.05, quadratic p < 0.05) were increased. Moreover, the myogenic differentiation factor 1 (MyoD1) mRNA expression and the mTOR mRNA expression and protein phosporylation were linearly (p < 0.05) up‐regulated, and the myostatin (MSTN) mRNA expression was linearly (p < 0.05) down‐regulated by betaine supplementation. Overall, this study indicated that betaine supplementation did not affect the growth performance of Cherry Valley ducks, but could linearly increase some amino acid contents in breast muscle, especially glycine, and increase muscle antioxidant activity to improve meat quality. Moreover, betaine supplementation could improve the breast muscle yield by increasing MyoD1 mRNA expression, decreasing MSTN mRNA expression and regulating mTOR signalling pathway.     

Effects of alpha‐lipoic acid supplementation on growth performance,antioxidant capacity and biochemical parameters for ammonia‐exposed broilers

In order to estimate the effect of alpha‐lipoic acid (LA) supplementation on relieving ammonia stress of broilers, 180 22‐day‐old male broilers were assigned to three groups, six replicates in each group and 10 birds per replicate. The three groups were: (1) a control group without ammonia stress; (2) exposure to 70 ppm atmospheric ammonia (AM); (3) exposure to 70 ppm atmospheric ammonia and administration of 300 mg/kg LA (AM + LA). The experimental period was 3 weeks. Results showed that average daily weight gain was increased and feed conversion ratio was decreased in the AM + LA group, compared with the AM group (P < 0.05). Total superoxide dismutase and glutathione peroxidase activities in serum, and glutathione content in liver were higher in the AM + LA group than that in the AM group (P < 0.05); however, serum malondialdehyde content was decreased by LA addition (P < 0.05). Additionally, serum glutamic‐pyruvic transaminase, creatine kinase and lactate dehydrogenase activities were reduced and albumin level was increased by LA addition (P < 0.05). In conclusion, LA addition could relieve ammonia stress to restore broiler production performance to normal levels.     

牛磺酸对肉仔鸡屠宰性能和肌肉品质的影响

本研究旨在探讨牛磺酸对肉仔鸡屠宰性能和肌肉品质的影响。选用240只1日龄艾维茵肉仔鸡,随机分为5组,每组3个重复。对照组饲喂玉米-豆粕型基础日粮,试验组在基础日粮中添加0.05%、0.10%、0.15%和0.20%的牛磺酸,试验期42 d。结果表明:(1)日粮中添加0.10%牛磺酸能够显著降低42日龄肉仔鸡胸肌失水率和粗脂肪含量(P<0.05),显著提高胸肌pH和粗蛋白质含量(P<0.05);(2)添加0.15%的牛磺酸显著提高42日龄肉仔鸡胸肌率和瘦肉率(P<0.05),显著降低皮脂厚(P<0.05),显著提高胸肌pH和粗蛋白质含量(P<0.05),显著降低胸肌粗脂肪含量(P<0.05);(3)0.20%的牛磺酸显著提高胸肌pH、肉色和粗蛋白质含量(P<0.05)。     

肉鸡品种对胴体性状和肉质的影响

本研究将清远麻鸡的两个纯系(A和B)与快速生长型AA肉鸡(C)杂交,在3个月的生长时间中测定了杂交品对肉鸡胴体性状、肌肉成分及氨基酸组成的影响.结果:杂交品系肉鸡的体重、屠体重、半净膛重、全净膛重、胸肌和腹脂重量均显著高于纯种品系(P<0.05).杂交品系肉鸡的肌纤维密度和剪切力较纯种品系显著提高了6.94％和7.98...     

L.fermentum F-6对肉鸡屠宰性能及肌肉品质的影响

试验旨在研究添加不同剂量的L.fermentum F-6对肉鸡的屠宰性能及肌肉品质的影响,进一步探讨其作为一种新型饲料益生菌的可行性。试验以玉米和大豆粕为主要原料配制日粮,采用单因子完全随机试验设计方法,选择1日龄雌雄各半的健康AA肉鸡240只,称重后随机分为4个组,其中1个对照组和3个L.fermenti F-6组,每个组6个重复,每个重复10只鸡,各组鸡的初始体重经方差检验差异均不显著(P>0.05)。对照组肉鸡不饲喂L.fermentiF-6,L.fermentiF-6组饮水饲喂L.fermentiF-6,添加水平分别为2×105、2×106和1×107 cfu/ml,试验期42 d。研究结果表明,添加L.fermenti F-6可显著提高肉鸡全净膛率和胸肌率(P<0.05),提高肉鸡屠宰性能,其中以添加剂量为2×106 cfu/ml时效果较好。添加L.fermenti F-6对肉鸡肌肉pH值、系水力和肉色指标无显著影响,但与对照组相比,L.fermentum F-6对肌肉系水力和肉色有一定改善效果。     

中草药与寡糖配伍对肉鸡抗氧化功能的影响

试验研究了中草药女贞子、五味子以及女贞子、五味子与葡萄糖甘露寡糖(MOS)配伍对肉鸡抗氧化指标的影响。选择180只1日龄肉鸡公雏随机分为6组,对照组饲喂基础饲粮,抗生素组在基础饲粮中添加5mg/kg黄霉素,试验组分别在基础饲粮中添加1%女贞子、1%五味子、1%女贞子+0.5%MOS、1%五味子+0.5%MOS。试验从1日龄开始,试验期56d。结果显示:女贞子、五味子可提高肉鸡心脏超氧化物歧化酶(SOD)活性(P<0.05),以及血清和组织谷胱甘肽还原酶(GR)活性(P<0.05),降低血清和心脏丙二醛(MDA)含量(P<0.05)。上述试验结果表明中草药添加剂能够提高肉鸡抗氧化功能。     

Effects of water‐misting sprays with forced ventilation on post mortem glycolysis,AMP‐activated protein kinase and meat quality of broilers after transport during summer

Effects of water‐misting sprays with forced ventilation on post mortem glycolysis, adenosine monophosphate‐activated protein kinase (AMPK) and meat quality of broilers after transport during summer were investigated in the present paper. A total of 105 mixed‐sex Arbor Acres broilers were divided into three treatment groups: (i) 45 min transport without rest (T); (ii) 45 min transport with 1 h rest (TR); and (iii) 45 min transport with 15 min water‐misting sprays with forced ventilation and 45 min rest (TWFR). Each treatment consisted of five replicates with seven birds each. The results indicated that the water‐misting sprays with forced ventilation could mitigate the stress caused by transport under high temperature conditions during summer, which reduced the energy depletion in post mortem Pectoralis major (PM) muscle. This resulted in a higher energy status compared to the T group, which would decrease the expression of phosphorylation of AMPK (p‐AMPK). Furthermore, decreased the expression of p‐AMPK then slowed down the rate of glycolysis in post mortem PM muscle during the early post mortem period, which in turn lessened the negative effects caused by transport on meat quality. In conclusion, water‐misting sprays with forced ventilation may be a better method to control the incidence of the pale, soft and exudative meat in broilers.