首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 359 毫秒
1.
本试验旨在研究饲粮维生素E水平对43 ～ 63日龄黄羽肉鸡肉品质和抗氧化功能的影响.选用1 440只43日龄岭南黄羽肉公鸡,采用单因子随机分组试验设计,共设6个处理,每个处理6个重复,每个重复40只鸡.试验采用玉米淀粉-豆粕型基础饲粮,各处理饲粮营养水平除维生素E水平不同外,其他均相同.空白对照组饲喂未添加维生素E的基础饲粮,其余各处理饲粮中分别添加5、10、20、40、80 mg/kg维生素E.试验期21 d,试鸡地面平养,自由采食颗粒料和自由饮水.结果表明:1)饲粮中维生素E添加水平对试鸡生长性能和胴体品质无显著性影响(P＞0.05).2)胸肌肉色的L*、a*、b *值和肌肉嫩度也未受饲粮维生素E添加水平显著影响(P＞0.05).添加各水平维生素E均显著提高了宰后45 min胸肌pH(P ＜0.05),添加5、10、40、80 mg/kg维生素E均显著提高了宰后24 h胸肌pH(P ＜0.05).添加20、40 mg/kg维生素E显著降低了宰后45 min胸肌滴水损失,添加5、10、40、80 mg/kg维生素E显著降低了宰后48 h胸肌滴水损失(P＜0.05).3)饲粮中添加不同水平维生素E对试鸡血清中丙二醛(MDA)含量和总超氧化物歧化酶(T-SOD)活性无显著性影响(P＞0.05),添加10、20 mg/kg维生素E使试鸡血清中谷胱甘肽过氧化物酶(GSH-Px)活性分别比对照组提高了27.51％、30.57％(P＜0.05).添加各水平维生素E均使试鸡肝脏中GSH-Px活性显著提高(P＜0.05),添加20、40、80 mg/kg维生素E均显著降低了肝脏中MDA含量(P＜0.05),显著提高了肝脏中α-生育酚含量和肌肉中T-SOD活性(P＜0.05).以上试验结果提示,饲粮中添加维生素E可提高43～63日龄黄羽肉鸡机体抗氧化功能,改善肉品质,且添加20 mg/kg效果较好.  相似文献   

2.
维生素K在动物骨骼发育中起着重要的作用,其机理主要是维生素K能够促进血清中骨钙素的羧化,羧化的骨钙素与羟基磷灰石的结合能力增强,促进了骨骼的矿化,从而改善骨骼质量。血清骨钙素的羧化程度是维生素K状态评定的一个新的敏感指标。为获得动物良好的骨骼质量和生产性能,应适当增加日粮中维生素K的添加量。  相似文献   

3.
1. Female chicks of a White Leghorn strain were fed three different diets from one day old: control, additional vitamin K3 (10 mg/kg), and a diet containing a combination of additional vitamin K3, sodium fluoride (10 mg/kg) and limestone in particulate rather than powdered form. At 16 weeks photoperiod was increased for half the birds from 8:16 L:D to 16:8 L:D immediately or by one hour per week to the same ultimate photoperiod for the other half. 2. Age at first egg was lower by 4.0 d for birds on the fast lighting regime but there were no overall effects of lighting on bone quality at either 25 or 70 weeks. 3. Additional vitamin K3 resulted in higher proximal tarsometatarsus cancellous bone volumes at 15 weeks and throughout the laying period compared with controls. Plasma osteocalcin concentrations were unaffected by vitamin K3 supplementation during growth. 4. The combination diet resulted in beneficial responses of 12 to 20% in most bone characteristics in hens at 70 weeks. The magnitude of these effects was similar to a previous study involving a particulate calcium source alone (Fleming et al., Poultry Science, 39: 434-440, 1998b). We conclude that the beneficial effects of the combined treatment over the lifetime of the hens were attributable mainly to the presence in the diet of a calcium source in particulate form.  相似文献   

4.
1. This study compared the effect of dietary supplementation with organic or inorganic selenium (Se) sources plus control amounts or large amounts of vitamin E (alpha-tocopherol acetate) in broilers raised at control (20 to 24 degrees C) or low (14.5 to 16.8 degrees C) temperatures after 2 weeks of age. 2. The following dietary treatments were used from one day old. Diet 1, the control diet, comprised a commercial diet containing 0.15 mg/kg inorganic Se and 50 mg vitamin E/kg feed. Diet 2 was the same as diet 1, supplemented with 0.15 mg/kg inorganic Se. Diet 3 was the same as diet 2 but was supplemented with 200 mg/kg vitamin E. Diet 4 was the same as diet 1, but inorganic Se was replaced with 0.30 mg/kg organic Se. Diet 5 was the same as diet 4, supplemented with 200 mg/kg vitamin E. 3. Low temperature reduced the growth rate of broilers; however, at 6 weeks, there were no differences in the body weights of birds fed on organic Se supplemented diets housed at low or control temperature. The feed conversion ratio was significantly affected by low temperature but not by diet. The heterophil/lymphocyte ratio was higher in chicks after one week in the cold, indicating mild stress. Blood triiodothyronine levels were significantly higher in birds after 1 and 4 weeks in the cold but thyroxin was not affected. 4. Organic Se supplementation increased relative lung weight at the control temperature, which might lead to greater respiratory capacity. Relative spleen weight significantly decreased in broilers fed diets supplemented with inorganic Se under cold conditions, a possible indication of chronic oxidative stress. 5. At the low temperature, supplementation with organic Se alone, or with inorganic Se and vitamin E increased glutathione peroxidase (GSHPx) activity and glutathione (GSH) concentration in the liver of broilers, which may indicate increased activity of birds' antioxidant defence against suboptimal environments.  相似文献   

5.
本研究旨在探讨铜和维生素A及其互作效应对内仔鸡生长性能及抗氧化功能的影响.试验选用1日龄艾维茵肉仔鸡448只,随机分为8组,每组4个重复,每个重复14只鸡.采用4×2(铜×维生素A)完全随机设计,饲粮铜的添加量分别为0、8、150、225 mg/kg,维生素A的添加量分别为1 500、5 000 IU/kg,分为2个生长阶段,前期为1～4周龄,后期为5～7周龄.结果表明:1)高铜( 150、225mg/kg)抑制了全期肉仔鸡生长性能,提高了全期血清铜蓝蛋白(Cp)和后期血清总超氧化物歧化酶(T-SOD)活性(P＜0.05).2)5 000 IU/kg维生素A组获得较好的生长性能,提高了全期血清T-SOD活性,降低了前期血清Cp活性(P＜0.05).3)铜和维生素A互作效应对前期体增重、血清Cp和T-SOD活性及全期料重比有显著影响(P＜0.05),且二者间存在互补作用.铜(8 mg/kg)×维生素A(5 000 IU/kg)组与铜(0 mg/kg)×维生素A(5 000 IU/kg)组对前期肉仔鸡获得良好生长性能和提高血清T-SOD活性均有促进作用,但对血清Cp活性有显著降低作用(P＜0.05).由此可见,在基础饲粮铜水平为16～23mg/kg时,铜的适宜添加量为前期8 mg/kg,后期0～8 mg/kg;全期维生素A的适宜添加量为5 000 IU/kg.  相似文献   

6.
本试验旨在研究饲粮添加胍基乙酸(GAA)对爱拔益加(AA)肉仔鸡生长性能、血液学指标、脏器指数、组织同型半胱氨酸含量以及组织形态的影响,以系统评价AA肉仔鸡对GAA的耐受性。试验选用540只1日龄AA肉仔鸡公雏,随机分为5个组,每组6个重复,每个重复18只鸡。5组试鸡分别饲喂在基础饲粮中添加0、800、1 600、4 000和8 000 mg/kg GAA的饲粮。试验期42 d,分为前期(1~21日龄)和后期(22~42日龄)2个阶段。结果表明:与对照组相比,饲粮添加800~4 000 mg/kg GAA显著提高了肉仔鸡前期、后期和全期平均日增重(P0.05),显著降低其后期和全期料重比(P0.05),但对各期平均日采食量均无显著影响(P0.05)。饲粮添加8 000 mg/kg GAA组的平均日增重、平均日采食量和料重比与对照组相比差异不显著(P0.05)。饲粮添加800~8 000 mg/kg GAA对21、42日龄肉仔鸡血常规指标、血清生化指标、脏器指数和组织同型半胱氨酸含量均无显著影响(P0.05)。饲粮添加4 000、8 000 mg/kg GAA对肉仔鸡肝脏和肾脏组织形态无不良影响。由此可见,肉仔鸡饲粮中添加GAA对其生长性能、血液学指标、脏器指数、组织同型半胱氨酸含量和组织形态无不良影响,肉仔鸡可耐受8 000 mg/kg GAA。  相似文献   

7.
1. A 56-d experiment was conducted to study the comparative influence of organic and inorganic dietary copper (Cu) sources on growth, blood characteristics and copper accumulation in organs of broilers. 2. A total of 480 Arbor-Acre unsexed broilers were fed on diets containing copper sulphate (CuSO(4)) or copper proteinate (Cu Pro) at concentrations of 50, 100 or 150 mg/kg of Cu supplementation. The birds were given a broiler starter diet from 1-28 d and a broiler finisher diet from 29-56 d which contained 30·8 mg/kg and 41·1 mg/kg basal copper concentration respectively. Growth performance, blood characteristics and Cu accumulation in organs of the broilers were measured. 3. At 28 d, Cu Pro-fed birds had improved feed conversion ratio compared with CuSO(4). At 56 d, birds fed on Cu Pro diets had significantly greater body weight than CuSO(4)-fed birds. Birds fed on CuSO(4) supplemented diets had significantly better feed conversion efficiency. Feed consumptions for the two Cu sources were not significantly different. At no stage did the concentration of added Cu affect the productive traits measured. 4. Cu Pro supplementation increased haemoglobin concentration but reduced plasma triglyceride and plasma cholesterol. Plasma cholesterol decreased as Cu concentration increased. 5. There was a greater accumulation of Cu in the blood, heart, lung, liver and bone of broilers fed on Cu Pro than in those receiving CuSO(4). The liver Cu concentration increased as dietary Cu concentration increased. 6. Cu Pro was more effective in promoting growth and reducing blood cholesterol, and was more bio-available in the organs of broilers.  相似文献   

8.
以玉米淀粉和低锌豆粕为主要原料构成含锌4．67mg／kg的半纯合低锌基础日粮，将150只1日龄艾维茵肉仔鸡随机分为3个自由采食组与2个限制采食组。其中．自由采食组日粮是在低锌基础日粮中分别添加0、5、80mg／kg的锌，各组的VA添加水平均为3000 IU／kg日粮。2个限制采食组的日粮锌添加水平为80mg／kg，其它营养成分及采食量控制到与相应的低锌组一致的水平。结果表明，日粮锌水平低于9．67mg／kg时，可引起肉仔鸡血清VA浓度的明显下降。日粮锌含量为4．67mg／kg时，血清VA浓度的下降既与缺锌本身有关，又与因缺锌继发的采食量下降有关；日粮锌含量为9．67mg／kg时，血清VA浓度的下降主要是由缺锌继发的采食量下降引起的。限制采食也可引起肉仔鸡血清VA浓度的下降，但对血清锌浓摩无明显的影响。  相似文献   

9.
1. The objective of the present study was to investigate the effect of vitamin E (VE, α-tocopherol acetate) on growth performance and meat quality of broilers fed on diets containing maize distillers’ dried grains with solubles (DDGS).

2. A total of 360 one-d-old broilers were randomly assigned to 6 groups. Each group comprised 6 replicates of 10 broilers. Broilers were allocated to 1 of 6 diets and fed for 49?d in a 3?×?2 factorial design. The dietary treatments included three concentrations of DDGS (0, 10 or 20%) and two concentrations of VE (0 or 200?mg/kg).

3. Diets containing 20% DDGS decreased the growth phase and average daily feed intake, demonstrating that small amounts of DDGS affected feed intake in broilers and that an excess of DDGS was not conducive to feed intake.

4. Different dietary concentrations of DDGS did not significantly improve colour, drip loss, cooking loss, or shear force. Supplementation with 200?mg/kg VE significantly reduced cooking loss and shear force and improved colour.

5. In conclusion, supplementation with DDGS at 10% and/or α-tocopherol acetate at 200?mg/kg had positive effects on growth performance and meat quality in broilers.  相似文献   

10.
本试验旨在研究在2种能量水平饲粮中添加大豆卵磷脂乳化剂对肉鸡生长性能、养分利用率和血清生化指标的影响。试验采用2×2因子完全随机区组试验设计,将960只1日龄科宝500白羽肉公鸡随机分为4组,每组6个重复,每个重复40只鸡。各组试验鸡分别饲喂2个能量水平和2个乳化剂添加水平组成的试验饲粮,其中代谢能分别为12.13和11.92 MJ/kg(1～21日龄)、12.96和12.65 MJ/kg(22～49日龄),乳化剂添加水平分别为0和265 mg/kg(1～21日龄)、0和400 mg/kg(22～49日龄)。试验测定肉鸡生长性能,能量、干物质、粗蛋白质和粗脂肪表观利用率,以及血糖、血脂和胆汁酸含量。结果表明:肉鸡采食正常能量饲粮前期(1～21日龄)平均日增重极显著高于低能量饲粮(P<0.01),肉鸡全期(1～49日龄)采食添加乳化剂的低能量饲粮料重比能达到正常能量饲粮水平;饲粮添加乳化剂有提高平均日增重和饲粮粗脂肪和能量表观利用率的趋势,可促进胆汁分泌,能显著降低前期及全期料重比(P<0.05)。结果显示,降低饲粮能量显著降低1～21日龄肉鸡平均日增重,提高1～21日龄和1～49日龄料重比;饲粮添加乳化剂能够改善饲料利用率,特别是在1～21日龄肉鸡低能量饲粮中效果更明显。  相似文献   

11.
OBJECTIVE: To assess effects of high dietary amounts of vitamin C or vitamin E and oxidative stress on the heart and growth performance of broilers maintained at an altitude of 2,200 m above sea level. ANIMALS: 360 chicks (1-day-old broilers). PROCEDURE: Birds were randomly assigned to 3 groups (120 chicks/group). Each group of birds was fed a specific diet (control group, basal diet containing 12 mg of vitamin E (DL-alpha-tocopherol acetate)/kg of feed without additional ascorbic acid; vitamin E group, basal diet supplemented with 75 mg of vitamin E/kg of feed; and vitamin C group, basal diet supplemented with 400 mg of ascorbic acid/kg of feed) throughout the entire 7 weeks of the study. Feed consumption and body weight of chicks were recorded on a weekly basis. Nine randomly selected birds from each group were euthanatized each week. Remaining birds were euthanatized at the end of the study. Samples of cardiac tissues were obtained to measure thiobarbituric acid reactive substances (TBARS), an indicator of oxidative stress. RESULTS: Vitamin E-supplemented diets resulted in better growth performance, lower rates of feed conversion, and lower TBARS content. Vitamin C-supplemented diets resulted in lower feed consumption and lower rates of feed conversion. When used separately, neither of the vitamins had any effect on mortality attributable to ascites syndrome. CONCLUSION AND CLINICAL RELEVANCE: It is recommended that diets supplemented with vitamin C, vitamin E, or both be fed to broilers maintained at an altitude of 2,200 m above sea level to improve growth performance.  相似文献   

12.
The aim of this study was to evaluate the effect of dietary supplementation of vitamin K (vit K) and Ca in the diets of laying hens on bone and blood parameters and performance during the growing phase and the effects on the laying phase up to 32 weeks. The study utilized 120 Hy‐Line W‐36 pullets in the growing phase (13–18 weeks), 80 laying hens in the production phase (20–32 weeks), distributed in a completely randomized design in a 2 × 5 factorial arrangement, two levels of Ca (0.8 and 1.4%) and five levels of vit K supplementation (0, 2, 8, 16 and 32 mg/kg) with four experimental units. An experimental diet was fed during the growing phase, and the commercial diet was fed during the production phase and were analysed for biochemistry and bone variables at 18 and 32 weeks. In pullets, a significant interaction of levels of vit K and Ca was observed for total serum calcium (mg/dl), Seedor index, Ca in the bones (%) and medullary bone (%). Pullets at 18 weeks of age, receiving diets with 1.4% Ca, displayed a quadratic effect of vit K with better results for these variables with 17.86, 14.59, 14.48 and 16.80 mg/kg of vit K, respectively. For level 0.8% Ca no effect of vit K was observed. The treatments during the growing phase had no effect on egg production, performance and biochemistry serum until 32 weeks. Medullary bone (%), there was a significant interaction for 1.4% Ca and a quadratic effect for vit K, with greater medullary bone areas observed with 6.09 mg/kg vit K in the diet. Supplementation with vit K in a diet with 1.4% Ca during the growing phase allowed for an increase in the area of medullary bone at 18 weeks, which was maintained until 32 weeks.  相似文献   

13.
1. Two experiments were carried out to investigate responses in performance and bone compositional and structural characteristics in broilers fed diets containing 4 concentrations of vitamin D3 (5, 20, 125 and 250 microg cholecalciferol/kg) at different concentrations of calcium, available phosphorus and vitamin A. 2. In experiment 1, body weight and tibia breaking strength were maximised at 14d with 250 microg vitamin D3/kg, tibia ash was maximised with 125 microg vitamin D3/kg. A high incidence of tibial dyschondroplasia (TD) was decreased to very low levels with 125 microg vitamin D/kg. 3. At 42d, performance and bone characteristics showed no response to vitamin D3 concentrations above 20 microg/kg. 4. Dietary vitamin A within the range 2-4 to 4.5 mg retinol/kg did not show any interaction with vitamin D3 status at either age. 5. In experiment 2, responses to vitamin D3 were strongly influenced by dietary calcium/available phosphorus. With 13 g calcium and 5 g available phosphorus/kg, performance and bone characteristics responded to vitamin D3 concentrations up to 125 microg/kg but more was needed at less optimal concentrations of calcium and available phosphorus. TD incidence was minimised with 250 microg/kg. 6. This study shows that high dietary concentrations of vitamin D3 can prevent TD. It is concluded that the vitamin D3 requirement of broilers up to 14 d of age at optimal dietary calcium and available phosphorus concentrations may be in the range 35 to 50 microg/kg for cortical bone quality and up to 250 microg/kg for prevention of TD. The vitamin D3 requirement for cortical bone quality after 14 d is not higher than 20 microg/kg. These requirements are much higher than earlier estimates and may be related to higher calcium requirements of modern broiler genotypes. Current regulations limiting maximum vitamin D3 concentrations in broiler starter diets may need to be reviewed.  相似文献   

14.
1. Three hundred and eighty 1-day-old Arbor Acres broilers were divided into control (A) and experimental (B, C, D, and E) groups. 2. After 14 d of age the experimental groups were subjected to a cool temperature challenge by lowering the temperature 1 to 2°C per day down to 12°C, and maintaining this temperature until 7 weeks of age. 3. At the same time, l.5 mg/kg 3,3,5-triiodothyronine (T 3 ) was added to the diet of groups D and E, and 500mg/kg ascorbic acid (vitamin C) to the diet of groups C and E. 4. The incidence of pulmonary hypertension syndrome (PHS), body weight gain and feed intake were measured weekly. Lung and blood samples were collected weekly from 10 birds per group beginning on d 14, and the percentage of thick-walled peripheral lung vessels (%TWPV) and packed cell volume (PCV) were determined. 5. The lower ambient temperature and diets supplemented with T 3 increased PHS incidence and % TWPV and decreased body weight gain. 6. There was an increase in PCV after 5 weeks of age under lower ambient temperature 3 and the PCV values 14 were also significantly increased by T 3 . 7. Vitamin C supplementation reduced PHS incidence and % TWPV but did not change packed cell volume, body, weight gain, feed intake, or feed conversion. 8. It is concluded that vitamin C reduced PHS and the associated muscularisation of pulmonary arterioles induced by exposing broilers to cool environmental temperatures and feeding them with T 3 .  相似文献   

15.
The objective of the current study was to evaluate the effect of feeding a thermo-tolerant xylanase in low-energy broiler diets on performance and processing parameters. Evaluation criteria included average broiler BW, FCR, livability, carcass yield, and fat pad yields. The experimental design consisted of 3 nutrient profiles: positive control, negative control 1 (−66 kcal/kg), and negative control 2 (−132 kcal/kg). Two xylanase inclusion programs were included in the negative control 1 and 2 diets; 60 g/t was included in the starter and grower diets with either 60 or 100 g/t in the finisher and withdrawal diets, yielding a total of 7 treatment groups with 8 replicate pens per treatment each containing 42-d-old straight-run chicks per treatment (2,352 total broilers). Broilers were reared in floor pens through 45 d of age. The dietary program consisted of 5 dietary phases: starter (1–15 d), grower 1 (16–23 d), grower 2 (24–31 d), finisher (32–38 d), and withdrawal (39–45 d). Body weights and feed consumption were determined on days of dietary changes, including d 15, 23, 31, 38, and 45. On d 45, 4 male and 4 female broilers per replicate (448 total) were subjected to an 8-h feed withdrawal period and processed to obtain carcass and fat pad weights. Reducing the dietary energy level increased FCR and decreased the fat pad weight of broilers in the negative control 2 treatment compared with the positive control. Inclusion of xylanase during the starter phase increased d 15 BW and reduced FCR. The inclusion of xylanase continued to reduce FCR throughout the trial, as compared with diets without xylanase inclusion. Within this study, we have demonstrated the effectiveness of xylanase inclusion in reduced-energy diets (−66 and −132 kcal/kg) to improve FCR of broilers to that of broilers fed energy-adequate diets.  相似文献   

16.
试验旨在研究日粮中添加蛋氨酸铬对肉鸡生长、脏器指数及血清生化指标的影响,为确定日粮中蛋氨酸铬的适宜添加量提供科学依据。试验选用1日龄AA肉鸡528只,设4个处理,每个处理4个重复,每个重复33只。对照组饲喂玉米-豆粕型基础日粮,其它处理组饲喂分别在基础日粮中添加蛋氨酸铬0.1 mg/kg(Ⅰ组)、0.2 mg/kg(Ⅱ组)、0.6 mg/kg(Ⅲ组)的日粮(以Cr3+计),试验期49 d。结果表明:蛋氨酸铬能显著降低饲料消耗(P<0.05),但对肉鸡各日龄段平均体重、料重比和成活率影响差异均不显著(P>0.05)。除能显著降低心脏相对重量(P<0.05)外,日粮中添加蛋氨酸铬对肉鸡其它脏器相对重量影响差异均不显著(P>0.05)。日粮中添加蛋氨酸铬对血液生化指标影响显著(P<0.05)。因此,日粮中补充蛋氨酸铬对肉鸡生产性能、脏器指数影响不明显;但对血液生化指标影响显著,建议日粮中蛋氨酸铬添加量以0.2 mg/kg为宜。  相似文献   

17.
Glycine has been reported to be conditionally essential for broilers fed reduced crude protein diets during the starter period. Research evaluating dietary Gly responses subsequent to the starter period is sparse. This experiment was conducted to ascertain the effects of feeding reduced crude protein diets supplemented with Gly and/or L-Gln (nitrogen source) on growth performance and carcass characteristics of broilers during a 41-day production period. Eight dietary treatments were utilized with the negative control diets formulated to contain approximately 2.4 and 0.29% points lower crude protein and total Gly + Ser concentrations, respectively, than the positive control diets. The 6 other diets were formulated to contain intermediate concentrations of total Gly + Ser and/or crude protein (nitrogen) by adding Gly and/or L-Gln, respectively, to the negative control diets. Glycine appeared to have more pronounced effects than nitrogen contribution on feed conversion ratio and body weight gain of broilers during starter and grower periods, whereas Gln improved feed conversion of broilers in the finisher period. Total breast meat weight and yield of broilers provided diets with the additions of Gly and L-Gln were higher than those receiving diets with only Gly or L-Gln supplementation. The positive outcomes on growth performance and carcass characteristics suggested that providing adequate total Gly + Ser and nitrogen concentrations in diet formulation may be necessary for broilers when dietary CP content was reduced approximately by 2.4% points during a 6-week production period.  相似文献   

18.
The effects of dietary supplemental nicotinic acid (NA) on growth performance, carcass characteristics and meat quality were investigated in three genotypes of chicken. Fast‐growing AA (Arbor Acres) broilers were compared with two genotypes of a slow‐growing local breed, Beijing‐You, that had undergone selection for and against intramuscular fat content respectively (BJY+IMF and BJY?IMF). The treatments were arranged 3 × 4 factorial completely randomized design. Day‐old females (n = 624) were allocated to four treatments with six replicates per treatment and fed diets (basal contained ～25 mg NA/kg) supplemented with 0, 30, 60 and 120 mg NA/kg. A sample of 72 birds from each genotype was slaughtered at market time (8 weeks of age for AA and 16 weeks of age for BJY). The breast muscles of AA broilers were darker, had less redness and yellowness, lower drip loss and higher shear force as compared to the BJY genotypes (p < 0.01). The highest drip loss and the lowest shear force among the three genotypes were apparent in BJY+IMF (p < 0.01). Increasing supplementation from 0 to 60 mg NA/kg tended to increase average daily gain (ADG), average daily feed intake, width of intermuscular fat band, thickness of subcutaneous fat (including skin) and percentage of abdominal fat but, for most variables, values decreased slightly with 120 mg NA/kg. Increasing supplementation to 60 mg NA/kg decreased (quadratic, p < 0.001) drip loss, but it increased at 120 mg NA/kg. The present results indicate that (i) the AA broilers fed corn–soybean meal based‐diets require approximately 60 mg NA/kg to maximize ADG and meat product yield and decrease the drip loss of breast muscle; (ii) the addition of 30 mg NA/kg meets the requirement of BJY genotypes; and (iii) there seems to be no beneficial effect of NA supplementation on chicken meat quality except for limiting the drip loss.  相似文献   

19.
In two experiments was investigated whether feeding with an air-dry feed mixed with different amounts of water and/or supplemental ascorbic acid affect performance and carcass compositions of broilers exposed to a high ambient temperature (35 to 37 degrees C for 8 h/d and thermoneutral for 16 h/d). In the first trial, 64 one-week-old male broiler chicks were fed ad libitum in four dietary treatment groups for a 6-week period. Experimental mash diets were prepared by mixing a maize-soybean based standard broiler starter or finisher with tap water in the ratios of 0.0:1.0, 0.5:1.0, 1.0:1.0 and 1.5:1.0 (water:air-dry feed, w/w). More water in the diet increased BWG, DMI, abdominal fat and carcass weight, carcass CP, crude fat, but it deteriorated DM conversion efficiency. In the second experiment, 64 one-week-old male broiler chicks were given air-dry or wet (water:feed, 1.5:1) starter or finisher diets without or with ascorbic acid supplementation (0 and 250 mg/kg air-dry feed, resp.) ad libitum for a 6-week period. Ascorbic acid supplementation increased BWG, carcass weight and carcass CP significantly, while reducing carcass crude fat content. However, feeding broilers with a diet mixed with water in a ratio of 1.5:1.0 increased BWG, DMI, carcass weight and carcass lipid markedly, but deteriorated DM conversion efficiency. There was also a significant interaction between ascorbic acid and wet feeding, whereby ascorbic acid supplementation induced a significant reduction in carcass lipid contents of broilers fed on air-dry diets but not on wet diets. It is concluded that wet feeding, especially an addition of 150% water to produce a porridge like consistency, improved growth performance by increasing fat, ash and protein deposition in the body, while reducing DM conversion efficiency. It is also concluded that under heat stress supplemental ascorbic acid in air-dry diets stimulates broiler performance but not in wet diets.  相似文献   

20.
Twelve Quarter Horses, 18 to 24 mo of age and having an average body weight of 460+/-12 kg, were randomly assigned to one of two exercise treatments (control and exercise) to study the effect of initiation of exercise training in young horses on vitamin K status. The control treatment consisted of hand-walking the horses 7 min/d and 5 d/wk for 180 d. Exercise consisted of the following treadmill exercise regimen: 2 min at 4.5 to 5.4 m/s, 3 min at 13.4 to 14.3 m/s, and 2 min at 4.5 to 5.4 m/s on 5 d/wk for 180 d. Both groups were allowed free access to brome grass hay (273 mg of phylloquinone/100 g) individually. Additionally, the exercise group was fed .45 kg of a grain-mix concentrate (40 mg of phylloquinone/100 g) on the days they were exercised. Jugular venous blood samples were collected at d 0, 30, 60, 90, 120, 150, and 180. Blood samples were analyzed for total serum osteocalcin and vitamin K status via the hydroxyapatite binding capacity of serum osteocalcin calculated as follows: Hydroxyapatite binding capacity of serum osteocalcin = [(total serum osteocalcin - serum osteocalcin following extraction of serum with hydroxyapatite)/total serum osteocalcin] x 100. All horses were killed with an overdose of sodium pentobarbital on d 180. Computed tomographic osteoabsorptiometry was used to measure relative bone density distribution on the surface of the distal radial carpal bone, proximal third carpal bone, and the distal third metacarpal condyle. Relative bone density distribution was measured in Hounsfield units and categorized as low-, medium-, and high-density bone corresponding to 800 to 1,199, 1,200 to 1,299, and 1,300 to 3,000 Hounsfield units, respectively. Carpal and metacarpophalangeal joints were assigned a score of 0 (normal) to 3 (severe) that reflected the presence and severity of joint lesions. Hydroxyapatite binding capacity of serum osteocalcin and serum osteocalcin were unchanged over the 180-d period in both groups. Exercised horses had a higher percentage of high density bone (P < .01) and a lower percentage of low density bone (P < .01) on the surface of the third metacarpal condyle and a higher cumulative gross lesion score (P < .01) in the metacarpophalangeal joint than controls. There were no differences between treatments in relative bone density distribution in the carpal bones, or cumulative gross lesion score of the carpal joints. No significant correlation was present between the serum measures, osteocalcin and hydroxyapatite binding capacity of serum osteocalcin, and the bone measures, relative bone density distribution and joint gross lesion score.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号