日粮镁对肉仔鸡腿肌中活性氧产量的影响

本试验目的是研究日粮镁水平对肉仔鸡腿肌中活性氧(reactive oxygen species , ROS)产量的影响。96只AA肉仔鸡随机分配到低镁日粮组和对照组,每组6个重复,每个重复8只鸡,分别喂以镁含量1 .2 g/kg或2 .4 g/kg的日粮。与对照组相比,低镁组肉仔鸡腿肌中谷胱甘肽(glutathione , GSH)的含量降低了27 %(P<0 .01) ,丙二醛(malondialdehyde, MDA)的含量提高了40 %(P<0 .01)。采食低镁日粮的肉仔鸡腿肌匀浆液的ROS信号峰的高度显著高于对照组(P<0 .01)。对照组腿肌镁的浓度(30 .27 mg/kg)显著高于低镁组腿肌镁的浓度(27 .40 mg/kg)。腿肌中铁、钙的含量在两组之间差异不显著(P>0 .05)。与对照组相比,低镁组腿肌线粒体复合酶Ⅰ、Ⅱ、Ⅲ、Ⅳ的活性分别提高了28 %、23 %(P<0 .01)、35 %(P<0 .01)和30 %,线粒体复合酶Ⅰ、Ⅱ、Ⅲ、Ⅳ的活性与ROS产量之间呈显著的负相关关系(P<0 .05)。除C18∶2的含量显著高于对照组外,其他多不饱和脂肪酸含量在两组之间没有差异。本试验结果表明低镁日粮实质性地提高肉仔鸡腿肌中ROS的产量,低镁日粮降低腿肌中镁的浓度,诱导了线粒体呼吸链酶活性升高,从而提高了ROS的产量。     

日粮中添加包被肉桂油对肉鸡屠宰性能、肌肉品质和风味的影响

为探究鸡日粮中添加包被肉桂油对肉鸡生长性能、屠宰性能、肌肉品质和肌肉风味的影响,试验选用168只1日龄罗斯308雏鸡,随机分成2个处理组,对照组饲喂基础日粮,试验组在基础日粮中添加300 mg/kg的包被肉桂油。结果显示:与对照组相比,试验组肉鸡活体重没有显著的差异(P>0.05);21日龄胸肌的a^*值和b^*值(P<0.05)和42日龄胸肌和腿肌的24 h pH值(P<0.05)提高,21和42日龄胸肌和腿肌的滴水损失(P<0.05)降低;21日龄胸肌中过氧化氢的含量和42日龄胸肌丙二醛含量(P<0.01)降低;腿肌中的甜味氨基酸(丝氨酸和甘氨酸)(P<0.05)和芳香族氨基酸(酪氨酸和苯丙氨酸)的含量(P<0.01)提高。研究表明:日粮中添加300 mg/kg的包被肉桂油能够改善肉鸡肌肉品质的部分指标,提高胸肌抗氧化力和腿肌风味。     

Combined effects of clenbuterol and various concentrations of protein on performance of broiler chickens

1. The effects of the beta-adrenergic agonist, clenbuterol (1 mg/kg diet) on the growth and muscle composition in female broiler chickens (14 to 32 d of age) fed on diets containing various concentrations of protein (220, 240 or 260 g protein/kg) were examined. 2. Body weight gain over the 18 d period increased linearly with increasing protein intake. The rate of gain was significantly higher in clenbuterol-treated chickens than in control birds. 3. Dietary clenbuterol increased thigh muscle weight and protein concentration of breast and thigh muscle, regardless of dietary protein content. Protein/DNA ratio in thigh muscle was enhanced by clenbuterol feeding, and the magnitude of difference of the ratio was higher in chickens fed on the 240 and 260 g CP/kg diets than in those fed the 220 g CP/kg diet. 4. It was concluded that clenbuterol-treated chickens require increased dietary protein to maintain maximal growth, and that increased protein consumption is an important factor in improving growth in clenbuterolfed broilers.     

Effects of astaxanthin‐rich dried cell powder from Paracoccus carotinifaciens on carotenoid composition and lipid peroxidation in skeletal muscle of broiler chickens under thermo‐neutral or realistic high temperature conditions

Thirty‐two 15‐day old broiler chicks (Chunky strain ROSS 308) were randomly divided into four treatments in a 2 × 2 factorial design. The main factors were diet (basal diet or basal diet supplemented with 0.15% astaxanthin‐rich dried cell powder (Panaferd‐P [astaxanthin 30 ppm]) and ambient temperature (thermo‐neutral [25 ± 1°C] or high [35 ± 1°C for 6 hr]). Dietary supplementation with Panaferd‐P did not affect growth performance, though high ambient temperature decreased feed intake and the weight of breast tender muscle, liver, and heart. High ambient temperature also decreased redness in both breast and leg muscles of chickens, while Panaferd‐P increased redness and yellowness of breast and leg muscles of chickens. Panaferd‐P increased Paracoccus carotinifaciens‐derived pigments (i.e., adonixanthin, astaxanthin, adonirubin, and cantaxanthin) as well as corn‐derived pigments such as zeaxanthin and lutein in breast and leg muscles. High ambient temperature increased the malondialdehyde (MDA) concentration in breast muscle, while Panaferd‐P decreased the MDA concentration in breast muscle under both temperature conditions. Our results suggest that dietary supplementation with Panaferd‐P increases muscle carotenoid content, the redness and yellowness of meat and decreases the muscle MDA concentration in broiler chickens kept under thermo‐neutral or high ambient temperature conditions.     

Corticosterone administration and high-energy feed results in enhanced fat accumulation and insulin resistance in broiler chickens

1. Two experiments were conducted to investigate the effects of exogenous corticosterone administration (30 mg/kg diet) and dietary energy level on feed or energy intake and fat deposition in broiler chickens of 1 and 4 weeks of age. 2. Corticosterone treatment significantly suppressed body weight (BW) gain and reduced feed and caloric efficiencies. The retarded growth may conceal the stimulatory effect of corticosterone on feed consumption or metabolisable energy (ME) intake. A high-energy diet may increase energy intake and partially alleviate the suppressing effect of corticosterone on growth of broilers. 3. Corticosterone administration promoted the conservation of energy stores as fat at both abdominal and subcutaneous sites and this process occurred regardless of dietary energy level in ad libitum feeding status. A high-energy diet increased fat accumulation and showed no significant interaction with corticosterone treatment. 4. The suppressed development of breast and thigh muscles by corticosterone treatment was observed only in 1-week-old chickens fed on the low-energy diet. In contrast, the yield of breast muscle but not thigh muscle was significantly decreased by corticosterone in 4-week-old chickens, suggesting that the tissue specificity to corticosterone challenge is age dependent. 5. Plasma concentrations of glucose, insulin, triglyceride, non-esterified fatty acids (NEFA) and very low density lipoprotein were increased by corticosterone treatment regardless of diet treatment. A high-energy diet increased plasma levels of NEFA and resulted in hyperinsulinism in 4-week-old chickens but not in 1-week-old chickens. 6. Lipoprotein lipase (LPL) activities in adipose tissues may have been up-regulated by corticosterone treatment and showed tissue specificity. The increased LPL activities at ad libitum feeding status were not necessarily linked with the increased fat accumulation in corticosterone challenged chickens. 7. Corticosterone resulted in augmented energy consumption and altered energy redistribution toward lipid deposition. The induced insulin resistance and enhanced hepatic de novo lipogenesis by corticosterone are likely to be responsible for the increased fat deposition.     

Electrolysed reduced water decreases reactive oxygen species-induced oxidative damage to skeletal muscle and improves performance in broiler chickens exposed to medium-term chronic heat stress

1. The present study was designed to achieve a reduction of reactive oxygen species (ROS)-induced oxidative damage to skeletal muscle and to improve the performance of broiler chickens exposed to chronic heat stress.

2. Chickens were given a control diet with normal drinking water, or diets supplemented with cashew nut shell liquid (CNSL) or grape seed extract (GSE), or a control diet with electrolysed reduced water (ERW) for 19 d after hatch. Thereafter, chickens were exposed to a temperature of either 34°C continuously for a period of 5 d, or maintained at 24°C, on the same diets.

3. The control broilers exposed to 34°C showed decreased weight gain and feed consumption and slightly increased ROS production and malondialdehyde (MDA) concentrations in skeletal muscle. The chickens exposed to 34°C and supplemented with ERW showed significantly improved growth performance and lower ROS production and MDA contents in tissues than control broilers exposed to 34°C. Following heat exposure, CNSL chickens performed better with respect to weight gain and feed consumption, but still showed elevated ROS production and skeletal muscle oxidative damage. GSE chickens did not exhibit improved performance or reduced skeletal muscle oxidative damage.

4. In conclusion, this study suggests that ERW could partially inhibit ROS-induced oxidative damage to skeletal muscle and improve growth performance in broiler chickens under medium-term chronic heat treatment.     

不同小麦日粮对肉仔鸡肉质、脂肪酸合成酶mRNA与脂蛋白脂肪酶mRNA表达的影响

本文旨在研究不同小麦日粮对肉仔鸡生长、肉质及脂肪酸合成酶(FAS)mRNA与脂蛋白脂肪酶(LPL)mRNA表达的影响。选用300只艾维因肉仔鸡公雏,随机分为5组,每组4个重复,每个重复15只鸡,5组分别饲喂玉米日粮和4种水溶性阿拉伯木聚糖(WSAX)含量不同的小麦日粮,试验期为6周。结果表明:①随着小麦日粮中WSAX含量的增加,肉仔鸡的生长明显降低;②小麦日粮显著增加了肌肉持水力,并随小麦WSAX含量增加而升高的趋势显著(P<0.01),剪切力也随之增加(P<0.05)。饲喂小麦日粮的肉仔鸡其肉色显著低于玉米日粮组(P<0.01),各小麦日粮组间差异不显著。当小麦WSAX含量较高时,小麦日粮可以显著降低肉仔鸡肌肉脂肪和胆固醇含量(P<0.05)。各处理间胸肌、腿肌含水量无差异(P>0.05);③小麦日粮显著降低FASmRNA在肉仔鸡肝中的表达量(P<0.01),并且随日粮WSAX含量增加而表达水平降低的趋势明显。各处理间LPLmRNA表达量的差异不显著(P>0.05)。本研究表明:①当小麦中WSAX含量较低时,对肉仔鸡增重和肉质的影响较小,是玉米理想的替代品;②当小麦中WASX含量较高,则会严重影响肉仔鸡的增重、肉质及FASmRNA在肝脏中的表达,不宜在肉仔鸡日粮中大量添加。     

母体日粮低能量对后代肉仔鸡生长性能、胴体品质和肉质的影响

本文旨在研究母体日粮低能量对后代肉仔鸡生长性能、胴体品质及肉质的影响.试验选用低脂系肉种鸡120羽,随机分成2组,每组60个重复,每个重复1羽,即单笼饲养.在肉种鸡产蛋期产蛋率达到5%进行试验处理,试验分试验组和对照组,试验组代谢能量为对照组的80%孵化后的肉仔鸡按照母体不同能量处理各挑选健康仔鸡,在相同的试验条件下进行饲养,试验期为56 d.结果表明:1)与对照组相比,母体日粮低能量有降低1日龄肉仔鸡体重的趋势,对全期日增重和料重比影响不显著(P＞0.05);2)与对照组相比,母体日粮低能量对后代肉仔鸡胸肌和腿肌的水分、脂肪和蛋白质含量,胸肌率和腹脂率均无显著影响(P＞0.05),但显著增加腿肌率(P＜0.05);3)与对照组相比,母体日粮低能量对后代肉仔鸡胸肌和腿肌的pH、红度、黄度、滴水损失和蒸煮损失均无显著影响(P＞0.05),但pH、红度和黄度值有升高趋势,滴水损失和蒸煮损失有降低趋势,胸肌和腿肌剪切力显著降低(P＜0.05);4)与对照组相比,母体日粮低能量显著提高后代肉仔鸡胸肌和腿肌肌纤维密度(P＜0.05),显著降低后代肉仔鸡胸肌和腿肌肌纤维直径(P＜0.05).本试验的研究结果表明:母体日粮低能量对后代肉仔鸡的胴体品质及肉质能产生一定的影响.     

饲养密度和高蛋白质饲粮代谢能水平对公母分饲肉鸡生长性能和腿部健康的影响

本试验旨在研究饲养密度与高蛋白质(前期23%,后期21%)饲粮代谢能水平对公母分饲肉鸡生长性能和腿部健康的影响。试验采用2(性别)×2(饲养密度)×3(饲粮代谢能水平)三因子完全随机设计,选用1日龄罗斯308(Ross 308)肉鸡公雏1 872只和母雏2 160只,随机分成12个组,每组8个重复。试验设高、低2个饲养密度,以出栏体重计,分别为42[高饲养密度(HSD),16公/m2或18母/m2]和26 kg/m2[低饲养密度(LSD),10公/m2或12母/m2]。试验饲粮分前期(1~21日龄)和后期(22~35日龄)2个阶段配制,饲粮代谢能设高、中、低3个水平,其中,高代谢能(HME)水平饲粮前期和后期的代谢能水平分别为12.81和13.23 MJ/kg,中代谢能(MME)水平饲粮前期和后期的代谢能水平分别为12.18和12.60 MJ/kg,低代谢能(HME)水平饲粮前期和后期的代谢能水平分别为11.55和11.97 MJ/kg。结果表明:1)饲养密度与饲粮代谢能水平对肉鸡的平均日增重和料重比有显著交互作用(P0.05)。1~21日龄时,随着饲粮代谢能水平增加,HSD组平均日增重的增加幅度和料重比的降低幅度均小于LSD组;22~35日龄时结果正好相反。性别与饲养密度对肉鸡的平均日采食量有显著交互作用(P0.05)。随着饲养密度增加,公鸡平均日采食量的降低幅度大于母鸡。2)HSD极显著降低肉鸡的胸肌率(P0.01),母鸡的胸肌率和腹脂率显著高于公鸡(P0.05)。饲粮代谢能水平和饲养密度对肉鸡的腿肌率有显著交互作用(P0.05)。随着饲粮代谢能水平增加,LSD组肉鸡的腿肌率降低,而HSD组基本不变。3)高饲粮代谢能水平极显著降低肉鸡的脚垫损伤评分(P0.01),公鸡的步态评分和脚垫损伤评分显著高于母鸡(P0.05),垫料水分含量显著低于母鸡(P0.05)。饲粮代谢能水平与饲养密度对肉鸡的脚垫损伤评分有显著交互作用(P0.05)。随着饲粮代谢能水平增加,HSD组脚垫损伤评分的降低幅度大于LSD组。以上结果表明,高饲养密度降低肉鸡的平均日增重,增加料重比;35日龄前,公鸡比母鸡的空间需求更高;提高高蛋白质饲粮的代谢能水平可以缓解HSD对肉鸡生长性能和脚垫健康的不利影响。     

Safety assessment of Bt 176 maize in broiler nutrition: degradation of maize-DNA and its metabolic fate.

Insect resistant Bt 176 maize has been developed by genetic modification to resist European borer infection. In the present investigation, the experiment was conducted to determine the effect of feeding a new hybrid of Bt 176 maize (NX 6262- Bt 176) on general health condition and performance of broiler chickens. Maize grains and diets were subjected to proximate analysis. Amino and fatty acids investigation were applied for both maize grains before used. To evaluate the degradation of NX 6262- Bt 176 maize DNA and its metabolic fate in broiler blood, muscles and organs. One-day-old male broilers were fed ad libitum on either an experimental diet containing NX 6262- Bt 176 or a control diet containing the non-modified maize grains for 35 days. Feed consumption and body weight were recorded weekly during the experimental period. All chickens were subjected to nutritional evaluation period at day 20 of age for 5 successive days, to calculate the percentage of apparent digestible nutrients in both diets. At day 35 samples were collected at several intervals after feed withdrawal. Prior to slaughter blood samples were collected from all birds by heart puncture to prevent DNA cross contamination. Samples from pectoral and thigh muscles, liver, spleen, kidney, heart muscle, bursa and thymus glands were collected. Digesta from different sections of the gastrointestinal tract (GIT) were collected as well. Packed cell volume (PCV) and some serum parameters were investigated. There were no significant differences between control and experimental group concerning chemical composition of feeds, apparent digestible nutrients, and all performance parameters measured (P > 0.05). Furthermore, there were no differences in the PCV and the analysed serum parameters between the control and experimental group. The results of maize DNA digestibility showed that the new variety takes the normal physiological passage along broiler GIT similar to the conventional line. In addition, Bt 176 maize DNA appears to be partially degraded in different parts of GIT comparable to the DNA of the control maize line. Results of the metabolic fate of maize DNA in broiler blood, muscles and organs indicated that only short DNA fragments (199 bp) derived from the plant chloroplast gene could be detected in the blood, skeletal muscles, liver, spleen and kidney, which disappeared after prolongation the fasting time. In heart muscle, bursa of Fabricius and thymus, no plant chloroplast DNA was found. Bt gene specific constructs from Bt 176 maize were not detected in any investigated blood or tissue samples.     

The effect of growth stimulators on the levels of various macroelements in chickens

Nitrovin administered at the dose of 15 mg per 1 kg of diet, cyadox (20 mg) and virgiamycin (10 mg) were studied as to their effect on the contents of calcium, sodium, potassium and magnesium in the blood serum, breast and thigh muscles, and feathers of chickens. The contents of calcium, sodium, potassium and magnesium in the blood serum ranged within the physiological limits. An increased content of calcium and potassium and a decreased content of sodium were recorded in the breast and thigh muscles, as compared with the control group. The contents of these macroelements in the feathers of the experimental group were significantly different from those in the birds of the control group.     

The unique physiological features of the broiler pectoralis major muscle as suggested by the three-dimensional ultrastructural study of mitochondria in type IIb muscle fibers

Typical skeletal muscles are composed of mixed muscle fiber types, which are classified as slow-twitch (type I) and fast-twitch (type II) fibers, whereas pectoralis major muscles (PMs) in broiler chickens are 100% composed of type IIb fast-twitch fibers. Since metabolic properties differ among muscle fiber types, the combination of muscle fiber types is involved in physiological functions and pathological conditions in skeletal muscles. In this study, using serial block-face scanning electron microscopy, we compared three-dimensional (3D) mitochondrial properties in type IIb fibers in broiler PMs and those in type I fibers of broiler gastrocnemius muscles (GMs) heterogeneously composed of slow- and fast-twitch muscle fibers. In type I fibers in the GMs, elongated mitochondria with numerous interconnections to form a substantial network among myofibrils were observed. Along with lipid droplets sandwiched by mitochondria, these features are an adaptation to effective oxidative respiration and constant oxidative damage in slow-twitch muscle fibers. In contrast, type IIb fibers in the PMs showed small and ellipsoid-shaped mitochondria with few interconnections and no lipid droplets, forming a sparse network. The mitochondrial spatial network comprises of active mitochondrial dynamics to reduce mitochondrial damage; therefore, type IIb fibers possess physiologically low capacity to maintain mitochondrial wellness due to static mitochondrial dynamics. Based on 3D mitochondrial properties, we discussed the contrasting physiological functions between type I and IIb fibers and proposed a high contractile power and low stress resistance as unique physiological properties of broiler PMs.     

五味子提取物对低脂系肉仔鸡肉质的影响

本试验采用单因子试验设计,将144羽1日龄健康、体重均一的低脂系肉仔鸡随机分为两组,每组6个重复,每个重复12羽。对照组饲喂基础日粮,试验组饲喂添加0.125%五味子提取物组的基础日粮,试验期为8周,研究五味子提取物对低脂系肉仔鸡肉质的影响。结果表明:(1)与对照组相比,五味子提取物组肉仔鸡胸肌纤维密度显著提高,腿肌直径显著降低(P0.05),腿肌纤维密度有升高趋势,胸肌直径有降低趋势;(2)与对照组相比,五味子提取物组胸肌和腿肌的水分、蛋白质与脂肪含量无显著差异(P0.05);(3)五味子提取物显著降低了肉仔鸡胸肌和腿肌剪切力(P0.05),胸肌和腿肌pH、红度(a*)、黄度(b*)有升高趋势(P0.05),滴水损失和蒸煮损失有降低趋势(P0.05)。     

Response time of broiler chickens to cimaterol: meat tenderness, muscle composition fiber size, and carcass characteristics.

The response time to cimaterol (CIM), a beta-adrenergic agonist, by broiler chickens for carcass characteristics, muscle composition, muscle fiber size, catheptic enzyme activity, and tenderness was determined. Two trials were conducted in which chickens were fed a control diet (CON) containing 0 ppm of CIM or a diet containing 1 ppm of CIM. Trial 1 consisted of 55, 31-d-old broiler chickens individually fed for up to 48 h. At 0, 6, 12, 18, 24, and 48 h, five CON and five CIM-fed chickens were killed. Trial 2 consisted of 160, 33-d-old broiler chickens group-fed for up to 14 d. At 2, 4, 6, 8, 10, 12, and 14 d, 10 CON and 10 CIM-fed chickens were killed. The breast muscle (BM) and leg muscle (LM) weight, cathepsin B and L activities, DNA, RNA, and protein concentration, and BM shear force value (SFV) were measured in both trials. Thigh muscle (TM) SFV were measured in Trial 2 only. Fiber size of BM was measured (five birds per treatment) at d 2, 6, 10, and 14. In Trial 1, BM weight and SFV were lower in CIM-fed birds at 6 h (P less than .05). In Trial 2 BM SFV were higher at d 8 (P = .06) and d 10 (P less than .05) in CIM-fed chickens. The SFV of CIM-fed chickens were higher at d 4, 8, 10, 12, and 14 (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Increased collagen III in culled chicken meat after feeding dietary wood charcoal and vinegar contributes to palatability and tenderness

We comprehensively evaluated meat quality in chickens fed a diet consisting of wood charcoal and vinegar (WCV) using food scientific and histological approaches. In culled hens, lipid and fatty acid in Musculus semimembranosus, cooking loss and sensory tests of whole thigh meat, and meat texture of breast meat were observed. In male broilers, cross section of M. semimembranosus was used for observations on muscle area, perimysium, non‐collagen total protein and total collagen content, and anti‐collagen I and III reactions. In frozen male broilers, conventional morphology of M. semimembranosus as well as chicken anti‐collagen III reaction to selected muscles of thigh meat and breast meat were compared between the control and WCV‐fed birds. Increased lipid and fatty acids, decreased cooking loss, high score in total evaluation for sensory test of thigh meat, and decreased meat texture values were observed for culled hens fed WCV. The higher values of muscle area, total collagen and collagen III were observed for broilers fed WCV. No perimysium collapse for M. semitendinosus or increased collagen III reactions of M. tensor fasciae latae, the flexor muscle group and M. pectoralis superficialis were observed for frozen muscles in the WCV group. These total results suggest that WCV produces palatable and tender meat by increasing collagen III.     

Dietary mannanase‐hydrolyzed copra meal improves growth and increases muscle weights in growing broiler chickens

The utilization of copra meal as a feed ingredient is limited because it contains a high level of mannan. However, recent findings indicate that the effect of copra meal on growth performance in broiler chickens can be improved by the supplementation of mannanase in the diet. In the present study, we examined the effect of mannanase‐hydrolyzed copra meal (MCM) on growth performance and muscle protein metabolism in growing broiler chickens (Gallus gallus domesticus). Forty 8‐day‐old male broiler chicks were assigned to two groups (four birds in each pen, five replicates) and fed either a commercial diet (as a control diet) or a diet containing MCM at 0.2% until 22 days of age. Dietary MCM significantly increased the weights of body, breast muscle, and thighs in chickens, whereas the weights of abdominal adipose tissue and liver were not affected. Cumulative feed intake was significantly increased by MCM. Dietary MCM significantly decreased plasma 3‐methylhistidine level. The messenger RNA and protein levels of muscle protein metabolism‐related factors were not altered by MCM. These findings suggest that the growth‐promoting effect of MCM is related to the suppression of muscle proteolysis in growing broiler chickens.     

Corticosterone administration and dietary glucose supplementation enhance fat accumulation in broiler chickens

1. The effects of exogenous corticosterone administration and glucose supplementation on energy intake, lipid metabolism and fat deposition of broiler chickens were investigated. 2. A total of 144 three-d-old male chickens were randomly assigned to one of the following 4 treatments for 7 d: a low energy diet (10.9 MJ ME/kg, 200 g/kg CP) with or without corticosterone (30 mg/kg diet) and drinking water supplemented with glucose (80 g/l) or saccharine (2 g/l, control). 3. Body weight (BW) gain and breast and thigh muscle yields (% body mass) were all significantly decreased by corticosterone treatment. The relative cumulative feed intake (RCFI) and relative ME intake (RMEI), rather than the feed (FI) or ME intake (MEI) were increased by corticosterone administration. Both feed efficiency (FE) and caloric efficiency (CE) were decreased by corticosterone administration. Corticosterone administration had no obvious effect on water consumption. 4. Glucose supplementation had no influence on BW gain and breast and thigh muscle yield (as % of body mass). FI or RCFI was decreased while MEI or RMEI was increased by glucose supplementation. FE was improved by glucose treatment, whereas CE was reduced. 5. Liver weight and abdominal, cervical and thigh fat deposits were all significantly increased by either corticosterone or glucose treatment. 6. Plasma concentrations of glucose, urate, triglyceride, non-esterified fatty acids (NEFA), very low density lipoprotein and insulin were all significantly increased by corticosterone treatment. Glucose supplementation had no obvious influence on any of the measured plasma parameters except for NEFA, which were significantly increased. 7. Lipoprotein lipase activities in either cervical or abdominal adipose tissues, rather than in thigh fat tissue, were significantly elevated by either glucose or corticosterone treatment.     

Dietary supplementation with pioglitazone hydrochloride and l-carnosine improves the growth performance,muscle fatty acid profiles and shelf life of yellow-feathered broiler chickens

The present study aimed to investigate the effects of dietary pioglitazone hydrochloride (PGZ) and l-carnosine (LC) supplementation on the growth performance, meat quality, antioxidant status, and meat shelf life of yellow-feathered broiler chickens. Five hundred broiler chickens were randomly assigned into 4 experimental diets using a 2 × 2 factorial arrangement with 2 PGZ supplemental levels (0 and 15 mg/kg) and 2 LC supplemental levels (0 and 400 mg/kg) in basal diets for 28 d. The feed-to-gain ratio decreased whereas the average daily gain increased with PGZ supplementation. Greater dressing percentages, contents of intramuscular fat (IMF) in breast and thigh muscles, C18:3n-6, C18:1n-9 and monounsaturated fatty acid (MUFA) percentages of thigh muscle were observed with PGZ addition. Additionally, significant synergistic effects between PGZ and LC on the C18:1n-9 and MUFA contents were found. Supplementation with LC decreased drip loss, cooking loss and total volatile basic nitrogen, and increased the redness (a∗) value, the superoxide dismutase and glutathione peroxidase activities in thigh muscles. Moreover, the malondialdehyde content decreased when diets were supplemented with LC, and there was a synergistic effect between PGZ and LC. Additionally, the mRNA abundance of lipogenesis-related genes, such as peroxisome proliferator-activated receptor γ (PPARγ), PPARγ co-activator 1α and fatty acid-binding protein 3, increased with PGZ supplementation, and relevant antioxidation genes, such as nuclear factor erythroid-2-related factor 2 and superoxide dismutase 1, were enhanced with LC supplementation. In conclusion, the results indicated that the supplementation of PGZ and LC could improve the growth performance, antioxidant ability, IMF content, and meat shelf life of yellow-feathered broiler chickens.     

大豆黄酮对母鸡蛋品质及后代仔鸡肉品质的影响

本文旨在研究添喂大豆黄酮对母鸡蛋品质及后代仔鸡肉品质的影响.试验选取产蛋后期肉种鸡480只,随机分为2组,每组设8个重复.试验组在基础日粮中添喂10 mg/kg的大豆黄酮,第5周后收集种蛋,每组随机取30枚做蛋品质分析,剩余种蛋按正常程序孵化,出雏后饲养至63日龄,宰杀取肌肉做肉品质分析.结果表明母鸡饲喂大豆黄酮后,蛋壳厚度和蛋壳比重分别增加了0.03 mm(P ＜ 0.01)和0.45%(P ＜ 0.05);蛋白的Haugh单位增加了4(P ＜ 0.05);入孵蛋出雏率和受精蛋出雏率分别降低了11.5%和8.3%(P ＜ 0.05).添喂大豆黄酮对后代仔鸡生长无显著影响,但显著降低了雌仔鸡肌肉比重和肌肉的蒸煮损失率(P ＜ 0.05),显著降低雄仔鸡肌肉的滴水损失率(P ＜ 0.05);显著增加胸肌黄度(P ＜ 0.05);但对腿肌的快慢肌纤维比例、纤维密度以及快慢肌纤维的横截面积均无显著影响(P ＞ 0.05).以上结果提示10 mg/kg剂量的大豆黄酮应慎用于种蛋禽上,而在商品蛋禽上则具有良好的应用前景.     

微生物处理对稻谷加工副产物营养品质的影响及其在肉鸡上的应用

文章旨在评估枯草芽孢杆菌发酵稻谷副产物对其营养品质的影响，并探讨该原料对肉鸡生长性能、组织器官相对重量及血清生化指标的影响。将初始体重为（46.09±0.12）g的600只商品肉仔鸡随机分为4组，每组5个重复，每个重复30只。稻谷副产物用1.5×108?CFU/kg枯草芽孢杆菌接种发酵48?h后，作为原料添加到肉鸡日粮中。对照组、T1～T3组肉鸡日粮分别添加0、60、120和180?g/kg微生物处理稻谷副产物。结果：稻谷副产物处理后粗蛋白质含量显著提高9.77%（P＜0.05），粗纤维含量显著降低29.77%（P＜0.05）。T3组肉鸡22～42?d及1～42?d平均日采食量分别较其他组显著降低19.01%、19.93%和28.78%（P＜0.05），12.65%、14.89%和20.46%（P＜0.05）。但T3组肉鸡22～42?d饲料报酬较其他组分别显著提高23.08%、24.67%和39.13%（P＜0.05），1～42?d饲料报酬较其他组分别显著提高12.86%、14.49%和25.40%（P＜0.05）。T3组肉鸡血清葡萄糖浓度较对照组和T1组分别显著提高11.67%和10.13%（P＜0.05），而T3组血清尿酸含量较其他组分别显著降低16.17%、12.64%和13.08%（P＜0.05）。结论：用1.5×108?CFU/kg枯草芽孢杆菌处理稻谷加工副产物可以提高其粗蛋白质含量，降低粗纤维水平。日粮中微生物处理稻谷副产物的添加水平达到18%时可以改善肉鸡饲料报酬。 [关键词]稻谷副产物|微生物处理|营养品质|肉鸡|生产