Effects of dietary supplemental L-carnitine and ascorbic acid on performance, carcass composition and plasma L-carnitine concentration of broiler chicks reared under different temperature.

The present study was initiated to determine whether dietary supplemental L-carnitine and ascorbic acid affect growth performance, carcass yield and composition, abdominal fat and plasma L-carnitine concentration of broiler chicks reared under normal and high temperature. During the experiment, two temperature regimes were employed in two experimental rooms, which were identical but different in environmental temperature. The regimes were thermoneutral (20-22 degrees C for 24 h) or recycling hot (34-36 degrees C for 8 h and 20-22 degrees C for 16 h). One-day-old broiler chicks (ROSS) were used in the experiment. A 2 x 2 x 2 factorial arrangement was employed with two levels (0 and 50 mg/kg) of supplemental L-carnitine and two levels (0 or 500 mg/kg) of supplemental ascorbic acid in drinking water under thermoneutral or high temperature regimes. Body weight gain was affected by high temperature. However, body weight gain was significantly improved in animals receiving supplemental L-carnitine, ascorbic acid or L-carnitine + ascorbic acid compared to animals receiving unsupplemented diet under high temperature. On the other hand, supplemental L-carnitine or L-carnitine + ascorbic acid reduced body weight gain under thermoneutral condition. Supplemental ascorbic acid significantly improved feed conversion efficiency, the improvement was relatively greater under high temperature. The L-carnitine content in the plasma was higher in the groups receiving supplemental L-carnitine and ascorbic acid under high temperature, while broilers fed supplemental L-carnitine and ascorbic acid had a decreased level of plasma L-carnitine concentration under normal temperature. It is concluded that dietary supplemental L-carnitine or L-carnitine + ascorbic acid may have positive effects on body weight gain, carcass weight under high temperature conditions.     

女贞子对肉仔鸡生长性能和胴体品质的影响

选用360只1日龄体重均一,健康的从肉鸡,随机分成对照组、5 mg/kg黄霉素组、0.5%和1%女贞子组,每组6个重复,每个重复15只鸡,试验期为6周,研究日粮中添加女贞子对内仔鸡的生长性能、胴体品质的影响.结果表明:(1)各阶段各试验组的日增重都显著高于对照组(P＜0.01),料重比均低于对照组,但差异不显著(P＞0.05).在0～3周龄和0～6周龄,0.5%和1.0%女贞子组日采食量都显著高于对照组(P＜O.05).(2)与对照组相比,0.5%和1.0%女贞子组能显著提高半净膛率(P＜0.05),显著降低腹脂率(P＜0.05).     

Effects of water sulfate concentration on performance, water intake, and carcass characteristics of feedlot steers.

Two hundred forty single-source, cross-bred steers (304 kg) were used to evaluate the effects of various water sulfate concentrations on performance, water intake, and carcass characteristics of feedlot steers. Cattle were stratified by weight and assigned within weight blocks to five water treatments. Averaged over time, actual water sulfate concentrations (+/- SEM) were 136.1 (+/- 6.3), 291.2 (+/- 15.3), 582.6 (+/- 16.9), 1,219.2 (+/- 23.7), and 2,360.4 (+/- 68.2) mg/L, respectively. Weather-related data were recorded. Increasing water sulfate concentration resulted in linear decreases in ADG (P < 0.01) and gain:feed ratio (P < 0.01) and a quadratic effect on water intake (P = 0.02) and tended to quadratically increase then decrease DMI (P = 0.13). Sulfate x period interactions were evident for DMI (P = 0.01), ADG (P < 0.01), and feed efficiency (P < 0.01). Time had quadratic effects on DMI, water intake, ADG, and feed efficiency (P < 0.01 for all models). Increasing water sulfate concentration resulted in linear decreases in final weight, hot carcass weight, and dressing percentage, a linear increase in longissimus muscle area, and a quadratic effect on fat thickness over the 12th rib and predicted yield grade (P < 0.05 for all dependent variables). Mean daily temperature explained 25.7% of the observed variation in water intake. Other factors that explained a significant (P < 0.01) amount of variation in water intake were BW, DMI, water sulfate concentration, barometric pressure, wind speed, and humidity. High water sulfate concentrations had a significant and deleterious effect on performance and carcass characteristics of feedlot steers. Increasing the sulfate concentration in water may have resulted in a functional water restriction early in the trial when ambient temperatures were greatest. However, toward the latter stages of the trial, cattle supplied higher-sulfate water had higher ADG and FE. These improvements later in the trial may represent compensatory gain associated with decreased ambient temperature and water requirements. Averaged over time, a water sulfate concentration of greater than 583 mg/L, equivalent to 0.22% of the diet, decreased feedlot performance.     

Effects of humic substances supplementation provided through drinking water on performance,carcass traits and meat quality of broilers

The present study aimed at evaluating the effects of different doses of humic substances (HS) in waterer pan on broiler performances and meat quality. For the trial, 480 chicks (ROSS 308) were allocated into four groups (HS0, HS150, HS300 and HS450) of 120 equally mixed‐sex birds, each receiving a drinking water supplemented with 0, 150, 300 and 450 ppm of a humic acid (provided by 0.0%, 0.5%, 1.0% and 1.5% of HS, v/v) respectively. At the age of 21 and 42 days, feed consumption and live weight were taken. At the age of 42 days, 16 birds per treatment were slaughtered, dressing percentages, digestive tract traits were evaluated and samples of breast (pectoralis major) and thigh (iliotibialis) meat were taken to evaluate the changes in colour characteristics (CIE L*, a* and b*) and chemical composition. The body weight gain increased by the HS300 in relation to the HS0 and HS450, and decreased by the HS450 in relation to the HS0. The feed consumption of birds in the HS450 and feed efficiency of birds in the HS300 were lower and higher than those in the other treatments respectively. The carcass weight of broilers in the HS150 and HS300 were higher than those of in the HS0 and HS450. The carcass weight decreased by the HS450 in relation to the other treatments. The dressing percentage increased by the HS150 in relation to the HS450. The HS450 resulted in breast and thigh meat colour that were lighter than those found in the HS0 birds. The HS450 increased fat content of thigh meat in relation to the HS0. It was concluded that the humic acid supplementation at 300 ppm and 450 ppm appears to have a measurable impact on live performance improving feed efficiency and lightness of breast and thigh meat colours in broilers respectively.     

合生素对白羽肉鸡生产性能及胴体品质的影响

1材料与方法1．1试验动物与设计试验选用内蒙古草原兴发股份有限公司培育的1日龄健康白羽肉鸡雏480羽,公母各半,按体质量随机分成4个处理组。处理A为正对照组（使用抗生素）;处理B为负对照组（不使用抗生素）;处理D为0．10％合生素组;处理E为0．05％合生素组。     

饮水中添加枯草芽孢杆菌对育肥期肉鸡生产性能的影响

为了验证在饮水中添加枯草芽孢杆菌是否能够提高肉鸡育肥期的生产性能,试验选取某公司3个鸡群健康的肉鸡场开展对比试验。结果表明,在饮水中添加枯草芽孢杆菌的试验组与对照组相比,试验期间的死亡率和采食量差异不显著（P>0.05）,试验期间增重试验组比对照组高5.63%,差异显著（P<0.05）,而试验期间的料肉比试验组比对照组低5.52%,差异显著（P<0.05）。     

合生素对白羽肉鸡生产性能及胴体品质的影响

合生素是将有益微生物与植物多糖结合起来、充分利用它们的互补作用而形成的一种理想的无毒害、无残留的饲用添加剂。大量动物试验表明,合生素产品已达到与抗生素相似的生产效果,且对肉品质有一定的改善作用。本试验使用合生素分别以0.1%和0.05%添加到白羽肉鸡日粮中,与正对照(     

红芪党参复方对肉仔鸡生长、代谢和胴体品质的影响

用180只0日龄的AA肉公鸡进行试验,研究红芪党参复方对肉仔鸡生长性能、养分代谢和胴体品质的影响。试验采用单因子完全随机设计,共分为3个处理组,分别为基础饲粮组及基础饲粮中添加5mg/kg的黄霉素组和1%的红芪党参复方添加剂组,每个处理6个重复,每个重复10只鸡。试验期42d,自由采食和饮水。结果表明,与基础饲粮组相比,饲粮中添加红芪党参复方添加剂能提高肉仔鸡0～21d的饲料转化效率(P=0.006);0～21d的钙(P0.001)、磷(P=0.005)和22～42d的干物质(P0.001)、粗蛋白质(P0.001)和磷表观存留率(P=0.007)以及胸肌率(P=0.006)。这些结果说明,红芪党参复方添加剂能提高肉鸡的生长性能、养分代谢和胴体品质。     

Effects of supplemental magnesium concentration of drinking water on pork quality

Thirty-two barrows were used to determine the effects of supplemental Mg in drinking water on pork quality. Pigs were determined to be free of the halothane and Napole mutations and were individually penned. After a 7-d adjustment period, barrows (111 +/- 1 kg BW) were blocked by BW and allotted randomly within block to 0, 300, 600, or 900 mg of supplemental Mg from Mg sulfate/L of drinking water for 2 d before slaughter. Pigs were not allowed access to feed (0.13% Mg) for 15 h before slaughter but continued to have access to experimental water treatments. Pigs were loaded and transported 110 km (1.75 h) to a commercial abattoir and remained in lairage for 5 h before slaughter. The LM was removed 24 h postmortem. Retail storage was simulated for 8 d, and the remaining LM was vacuum-packaged for 25 or 50 d at 4 degrees C. Plasma Mg concentration increased linearly (P = 0.001) with Mg supplementation; however, Mg concentration of the LM was not affected (P = 0.99) by Mg supplementation. Surface exudate, drip loss, and retail fluid loss of the LM were not affected (P > 0.10) by Mg. Lightness (L*) and redness (a*) of the LM were not affected (P > 0.10) by Mg, with the exception of initial redness (cubic; P = 0.05). Pigs supplemented with 300 or 900 mg of Mg/L had lower yellowness (b*) values of the LM displayed for 0 to 6 d than pigs supplemented with 0 or 600 mg of Mg/L (cubic; P < 0.05). Lightness of the LM after 25 (quadratic; P = 0.03) or 50 (quadratic; P = 0.04) d of vacuum-packed storage was greater at 300 and 600 mg of Mg/L than at 0 or 900 mg/L. Yellowness tended to be greater after 50 d, but not after 25 d, of vacuum-packaged storage for 300 or 600 mg of Mg/L compared with 0 or 900 mg/L (quadratic; P = 0.08). Oxidation of the LM, determined by thiobarbituric acid reactive substances after 4 d of retail storage, increased linearly (P = 0.05) as Mg increased in the drinking water. Furthermore, oxidation of the LM after 8 d of retail storage tended to increase linearly (P < 0.10), primarily because of the high oxidation of LM from pigs supplemented with 900 mg of Mg/L compared with controls (224 vs. 171 +/- 19 microg/kg, respectively). Oxidation of the LM was greater for pigs supplemented with 300 or 900 mg/L compared with 0 or 600 mg of Mg/L (cubic; P < 0.06) after 25 d of vacuum-packed storage. Magnesium did not improve pork quality characteristics of practical significance in pigs without the halothane and Rendement Napole mutations.     

Effects of supplemental L-carnitine in drinking water on performance and egg quality of laying hens exposed to a high ambient temperature

The present study was conducted to investigate effects of L-carnitine supplied with drinking water on performance and egg quality of laying hens under high environmental temperature. In the study, 47-week-old laying hens (Brown hisex) were divided into two groups (control and treatment) and fed with a standard layer diet. Treatment group was received 50 p.p.m L-carnitine with drinking water for an 8-week period. Throughout the study, 8 h hot (35-37 degrees C) and 16 h thermoneutral (20-22 degrees C) environmental temperature regime was employed daily. The results showed that L-carnitine supplementation affected some egg quality characteristics of layers under high environmental temperature. Relative albumen weight and height were increased (p < 0.05) by supplemental L-carnitine. Live weight gain, feed intake, egg mass, egg weight, yolk weight, shell weight, yolk index, egg-shape index, yolk colour score and shell thickness were not affected (p < 0.05) by L-carnitine. It is concluded that L-carnitine supplementation in laying hens could have potential to improve albumen quality under high environmental temperature.     

Growth performance,carcass characteristics,meat quality and serum profile of broiler chicks fed on housefly maggot meal as a replacement of soybean meal

A study was conducted to invesstigate the housefly maggot meal (HMM) as an alternative protein source to replace the soybean meal in broiler chick's diet. A total of 720 1-day-old male broiler chicks were divided into three groups and fed diets formulated with HMM to replace soybean meal at the rate of 0%, 4% and 8%. The study lasted for 42 days in two phases. Results showed that HMM addition did not markedly affect body weight, average daily body weight gain and average daily feed intake of the broiler chicks. Feed conversion ratio increased linearly (1–21 days) in starter or quadratically (22–42 days) in the grower phase. HMM non-significantly increased the feed intake and body weight during the grower phase. Slight changes were observed for decrease of blood biochemical indices in the platelets (day 21), and alkaline phosphatase and lysozyme (day 42), and increase for red blood cells, packed cell volume, total protein and uric acid on day 42; however, the fluctuations were within the physiological range. Non-significant effects were observed for carcass composition and meat quality, except that HMM numerically reduced the shear force of breast muscle (linear, p = .058). These results are the strong evidence that HMM can be used as an alternative protein source at 8% in broiler chick's diet without any adverse effect on chick's performance.     

Effects of wheat variety and specific weight on dietary apparent metabolisable energy concentration and performance of broiler chicks

1. This study used 4 wheat cultivars (Brigadier, Chaucer, Consort, Reaper) from three locations (Crossnacreevy, C; Downpatrick, D; Limavady, L), which had given rise to differences in wheat specific weight (SW), to examine the relationships between apparent metabolisable energy (AME) concentration, broiler performance and wheat SW. 2. The diets contained (g/kg): wheat 744, casein 142, blended vegetable fat 50, dicalcium phosphate 22, potassium bicarbonate 10.8, sodium bicarbonate 7.5, arginine 5, methionine 2, binder 8, trace minerals/vitamins 7.2, titanium dioxide 1.5. The diets were heat-treated (80 degrees C for 2 min) prior to pelleting (3 mm die). 3. SW ranged from 63 to 77 kg/hectolitre (hl), averaging 66, 69 and 76 kg/hl at D, C and L, respectively. In vitro viscosity of the wheat samples ranged from 5.2 to 17.5 cps and thousand grain weight (TGW) from 33.4 to 47.3 g. Mean TGW was similar at C and D (38.7, 37.0 g) but higher at L (43.1 g). In vitro viscosity was similar at C and L (11.2, 10.2 cps) but somewhat higher at D (14.4 cps). Crude protein (6.25 N) ranged from 116 to 147 g/kg and tended to be higher at D. Starch, which ranged from 612 to 656 g/kg, was least at D (617 g/kg) and greatest at L (641 g/kg). 4. Crude protein, crude fibre and total non-starch polysaccharide (NSP) were negatively correlated with SW, the R2 being respectively 0.38 (P<0.05), 0.16 (NS) and 0.45 (P<0.05). TGW and starch concentration were positively correlated with SW (R2=0.70, 0.44, respectively). There was a weak (NS) negative relationship (R2=0.19) between in vitro viscosity and SW. For both TGW and in vitro viscosity, correlations improved when variety was taken into account (R2=0.95, 0.92, respectively). 5. There were no significant effects of variety on dry matter (DM) intake or live weight gain (LWG). Gain: food was significantly higher (P<0.05) for Consort than for the other three varieties and the metabolisable energy ratio (ME:GE) just failed to attain significance (P=0.062). Calculated wheat AME (MJ/kg DM) was significantly (P<0.05) higher for Consort than for the other three wheats. There was a good correlation (R2=0.49) for the total data set between gain:food and ME:GE. In vivo viscosity varied from 13.6 to 28.6 cps for individual treatments and was significantly affected by variety (P<0001). 6. Although there were no significant differences in DM intake or LWG due to site the values for L (SW 76) were 6 and 5% lower, respectively, than for D (SW 66). Gain:food was lower (P<0.05) for C (SW 69) than for D. ME:GE, wheat AME and ME:gain were not significantly different between sites. 7. There was a weak (R2=0.18) positive relationship between ME:GE and SW corresponding to a 2.5% increase in energy value for a 10 kg/hl increase in SW and no relationship between gain:food and SW. When variety was taken into the regression the slope was similar but R2 increased to 0.82. 8. ME:GE and wheat AME concentration were negatively correlated with wheat in vitro viscosity (R2=0.64, 0.55, respectively). 9. It was concluded that in vitro viscosity appears to provide a better basis than SW for prediction of the nutritive value of wheats of unknown variety. If the variety is known then SW could be used to predict energy value. However, the effect of quite a large change in SW (10 kg/hl) was relatively small.     

Effects of increasing zinc supplementation in drinking water on growth and thyroid gland function and histology in broiler chicks

The aim of the study was to examine the effects of increasing zinc supplementation on growth, feed efficiency and thyroid function and histology in broiler chicks. Sixty new born male broiler chicks were randomly allotted into one of four treatment groups and fed for 60 d. Zinc (Zn) was added into drinking water at the levels of 0, 125, 500, and 1000 mg Zn/L. Body weight gain were significantly higher and feed efficiency were significantly lower in chicks supplemented with 125 mg Zn/L compared with chicks supplemented with 500 or 1000 mg Zn/L at the end of the experiment. Serum Zn concentration linearly increased with the increasing level of Zn intake. Serum triiodothyronine and thyroxine levels and the diameters of follicles of thyroid gland were significantly reduced with high levels (500 and 1000 mg Zn/L) of Zn intake at the end of the experiment. It was concluded that chick receiving 1000 mg Zn/L as ZnSO4.7H2O in drinking water showed signs of Zn toxicity.     

早期数量限饲对肉用仔鸡生产性能、胴体品质的影响

试验研究了早期数量限饲对肉用仔鸡生产性能、胴体品质的影响。以320只1日龄AA+肉用仔鸡为试验动物。设4个处理组,每个处理组4个重复,每个重复20只肉仔鸡。对照组根据AA+商品代肉鸡营养标准配制。各处理肉用仔鸡1～7日龄均为自由采食,8～14日龄对照组、限饲90%组、限饲80%组和限饲70%组分别饲喂自由采食量的100%、90%、80%和70%,15日龄恢复自由采食,以后按常规饲养管理。每周末,以重复为单位全部称重。分别于42、49日龄,每个重复随机抽取4只肉用仔鸡禁食12h、称重、屠宰、测定屠体品质。试验结果表明:在第2周,限饲各组肉仔鸡的体重和日增重分别显著低于对照组(P0.05);在第3周,限饲90%组完成补偿生长,体重与对照组差异不显著(P0.05);在第4周,限饲80%和70%组完成补偿生长,体重与对照组差异不显著(P0.05);5、6、7周及2～6、2～7周各组在体重、日增重、日采食量和饲料转化率等都无显著差异(P0.05)。早期数量限饲对肉仔鸡胴体特性没有显著影响(P0.05),限饲70%～80%,具有改善饲料转化效率、胸肌率、腹脂率的作用。     

核黄素对肉仔鸡免疫功能和生产性能的影响

100只1日龄肉仔鸡随机分成4组，每组25只，I－Ⅲ组为试验组，第Ⅳ组为对照组。对照组喂以基础日粮，其他3组分别喂以含核黄素3．6、7．2、14．4mg/kg的日粮，饲喂6周后观察它们对肉仔鸡外周血细胞、免疫器官及生产性能的影响，结果表明：各试验组鸡血浆中白细胞及异嗜细胞数目均高于对照组，其中Ⅱ、Ⅲ组异嗜细胞数与对照组差异显著（P＜0．05）；脾体比试验Ⅱ、Ⅲ组与对照组有显著差异，I组与对照组无差异；各试验组生产性能也均高于对照组。试验结果表明，核黄素可提高机体的抗感染能力及和免疫力，并可提高肉仔鸡生产性能。     

Growth performance and meat quality of broiler chickens supplemented with Rhodopseudomonas palustris in drinking water

1. The effect of the bacterium, Rhodopseudomonas palustris, on the growth performance and meat quality of broiler chickens was investigated.

2. A total of 900-d-old Arbor Acres broilers were allocated to three experimental treatments for 6 weeks. Chicks were administered with R. palustris in drinking water as follows: (i) control group without R. palustris; (ii) treatment 1 (R1) with R. palustris of 8 × 10⁹ cells per chick per day in drinking water; (iii) treatment 2 (R2) with R. palustris of 1.6 × 10¹⁰ cells per chick per day in drinking water.

3. The results showed that, compared with that of control, both groups of R. palustris treatment increased daily weight gain and improved feed conversion ratio of broiler chickens significantly during the whole growing period of 6 weeks.

4. Both total and glutamic acid contents of chicken breast fillet in R. palustris treatment R2 were higher, while the fat content was lower, than those of the control group. Furthermore, R. palustris treatments also improved sensory attributes of chicken breast fillet.

5. As a probiotic providing rich nutrients and biological active substances, R. palustris administration in drinking water displayed a growth promoting effect and improved meat quality of broiler chickens.     

Effects of feeding different concentration and forms of zinc on the performance and tissue mineral status of broiler chicks

1. Two studies were conducted to investigate the effect of feeding different concentration and forms of zinc (Zn) on the performance and tibia Zn status of broiler chicks.

2. In Experiment 1, chicks fed on the control or the diet supplemented with 12?mg of Zn as sulphate had lower feed intake, weight gain and tibia Zn content than other treatment groups. Chicks given 12 and 24?mg of organic Zn in starter and grower phases, respectively, had the same performance and tibia Zn content as those fed 40?mg of Zn as sulphate and the same performance but higher tibia Zn content than those given 12?mg of Zn as organic over the 42?d.

3. In Experiment 2, chicks given 24?mg organic Zn had greater weight gain than chicks fed on the other treatment diets in the starter period. Chicks fed on the control diet had lower tibia Zn content than chicks fed other treatment diets. Chicks given 80?mg Zn as sulphate had higher tibia Zn content than chicks fed the other treatment diets except those given 40?mg of Zn as sulphate.

4. The results from these trials indicate that feeding lower concentration of Zn as organic form may better promote the growth performance of broiler chicks.     

维生素C、E及其交互作用对肉仔鸡生长性能及鸡肉品质的影响

本试验旨在研究维生素C、E(VC、VE)及其交互作用对肉仔鸡生长及其鸡肉品质的影响。试验采用4×4完全随机试验设计将800只1日龄健康的艾维茵肉仔鸡随机分成16个处理,每个处理5个重复,每个重复10只。其中,VE设4个添加水平,分别为50、100、200、400 mg/kg日粮,VC的添加水平为50、100、200、400 mg/kg日粮。结果表明:在生长前期(0～21 d),日粮VE、VC的添加量对肉仔鸡日增重均无显著影响(P>0.05),VE、VC的互作效应在生长前期对肉仔鸡日增重和料重比的影响均不显著(P>0.05),前期VE(200 mg/kg)×VC(50 mg/kg)组料重比最低;在生长后期(4～6周龄),日粮VE、VC的添加量对肉仔鸡日增重、料重比的影响均显著(P<0.05),VE、VC的互作效应对肉仔鸡生长后期日增重和料重比的影响均显著(P<0.05);不同的VE、VC处理组之间pH 45 min、pH 12h、pH 24 h值、肉色、肌间脂肪、最大剪切力的差异均不显著(P>0.05),且VE、VC之间无显著的互作效应(P>0.05);不同维生素E组之间的滴水损失率差异极显著(P<0.01),...