Monoterpene concentrations in fresh,senescent, and decaying foliage of singleleaf pinyon (Pinus monophylla Torr. & Frem.: Pinaceae) from the western Great Basin

Senescent foliage from pines is potentially a large contributor to the total monoterpene content of the litter layer, and the availability of these compounds as phytotoxins may result from release of these compounds into the vapor phase. In order to determine the fate of several monoterpene hydrocarbons in the natural environment, we examined their concentrations in fresh, senescent, and decaying needles from 32 single-leaf pinyon pine (Pinus monophylla Torr. & Frem.: Pinaceae) trees growing at two different locations. Total monoterpene content was highest in the fresh needles (mean=5.6 ± 2.2 mg/g extracted air dry weight), but also remained relatively high in senescent needles (mean=3.6 ±1.8 mg/g extracted air dry weight), either still attached to the tree or forming the freshest layer of understory litter. Decaying needles within a dark decomposing layer of litter material 5–20 cm from the surface were found to contain much lower amounts of total monoterpenes (average: =0.12 ±0.06 mg/g extracted air dry weight). Further investigation of the fate of these compounds in the pinyon understory is required to determine if these hydrocarbons are indeed exerting phytotoxic characteristics.     

Simulation of a localized heating system for broiler brooding to improve energy performance

The aim of this work is to evaluate the performance of an innovative localized solar‐assisted pen heating system for brooding using a 3D computational simulation model of the heated space. The warm air‐curtained pen ensures acceptable temperature, air velocity, relative humidity, and air quality that meet the ventilation and heat requirements for a typical pen of 100 chicks as recommended by the American Society of Heating Refrigeration and Air Conditioning Engineers and American Society of Agricultural and Biological Engineers. The supply flow characteristics and the simulated velocity and temperature field of the curtained region were determined such that they meet the ventilation requirements and comfort criteria. Results show that air supplied at 40°C is capable of delivering the desired microenvironment at bird level while the heat input to the unit is 685 W when outdoor temperature is ?5°C. The system's energy performance was then analyzed using a prototype of 16 pens. The energy consumption of the new heating scheme consumed one third of the energy required by conventional non‐localized system. Moreover, integrating the new design with a solar system utilizing parabolic concentrators provided 72% of the power load from solar energy during a winter flock operation and 100% during other seasons. Copyright © 2013 John Wiley & Sons, Ltd.     

酶制剂+益生菌与植物提取物协同对肉鸡生产性能、免疫能力及抗氧化能力的影响

本实验旨在研究酶制剂+益生菌与植物提取物对肉鸡生产性能、免疫能力及抗氧化能力的影响。实验选取192只1日龄天露黑鸡2号,随机分为8组,每组4个重复,每个重复6只鸡,实验时间为21 d。对照组饲喂基础日粮,抗生素组饲喂基础日粮加250 g/t的4%恩拉霉素,实验Ⅰ、Ⅱ、Ⅲ组分别饲喂基础日粮加100、300、500 g/t含有益生菌与酶制剂的添加剂A,实验组Ⅳ、Ⅴ、Ⅵ分别饲喂基础日粮加200、500、800 g/t含有益生菌、酶制剂与大蒜素的添加剂B。结果表明：添加剂A与添加剂B都能够提高肉鸡平均日增重。添加剂A与添加剂B都会显著降低血清中葡萄糖与尿素氮浓度(P<0.05),极显著降低总胆固醇、甘油三酯、免疫球蛋白、白细胞介素-10浓度(P<0.01),极显著增加白细胞介素1-β与肿瘤坏死因子-α浓度(P<0.01)。研究表明,适量添加添加剂A或添加剂B能够起到与抗生素相类似的作用,在一定程度上能够替代恩拉霉素。     

Microorganisms and Cellulose Digestion in the Gut of the Woodlouse Porcellio scaber

In the common woodlouse Porcellio scaber different parts of the gut were observed with respect to microbial counts, cellulose activity, and degradation of cellulose. Cellulose is mainly digested in the anterior part of the hindgut, as was indicated by the distribution of cellulolytic activity and the decrease of cellulose content inside the gut. The cellulases woodlice utilize for the degradation of litter are mainly produced by endosymbiotic bacteria in the hepatopancreas rather than by microorganisms ingested with the food. Microorganisms ingested with the litter are digested in the anterior part of the hindgut and may provide an important food source. In the posterior hindgut, bacterial proliferation ensures microbial colonization of feces.     

电梯不同负载下的功能设置

围绕电梯负载时的功能设置命令编制 ,针对电梯不同负载情况设定相应的功能 ,使电梯的运行更加科学、合理、有效。     

湖北早籼糙米营养价值研究(III)——糙米代替玉米作能量饲料对蛋鸡产蛋率和肉鸡增重与肉蛋品质影响的研究

以同一批孵化 1日龄AA肉鸡 4 4 0只、2 9周龄伊莎产蛋高峰期母鸡 4 0 0 0只 ,随机各分为Ⅰ、Ⅱ、Ⅲ和Ⅳ四个组 ,肉雏鸡每组 110只 ,产蛋母鸡每组 10 0 0只。两种鸡日粮中以糙米代替玉米 ,Ⅰ组为 0 ,即为对照组 ,Ⅱ组为 50 % ,Ⅲ组为 75% ,Ⅳ组为 10 0 %的处理 ,按单因子设计 ,进行对比饲养试验 ,肉鸡正试期 4 5d ,试验结束时进行屠宰试验 ,测定肉品质 ,产蛋鸡正试期 30d ,试验中采蛋进行蛋品质测定。对肉鸡以日增重、料肉比和肉品质为指标 ,产蛋鸡以产蛋率、料蛋比和蛋品质为指标 ,来考察糙米作为能量饲料的饲养效果和营养价值。试验结果 ,Ⅰ、Ⅱ、Ⅲ和Ⅳ组 ,肉鸡的日增重依次为 4 2 .7、4 4 .7、4 7.8和 50 .4g ;料肉比依次为 2 .12、2 .0 9、2 .0 4和1.96 ;肉品质各组接近 ,处于良好水平 ;蛋鸡产蛋率依次为 92 .5%、91.8%、93.2 %和 91.7% ,料蛋比依次为 2 .70、2 .75、2 .6 5和 2 .71,蛋品质各组间差异不显著 (P >0 .0 5) ,且居较好水平。结果表明 ,肉鸡和产蛋鸡各组间的各项考核指标与全玉米日粮组均很接近 ,差异不显著 (p >0 .0 5) ,证明了早籼糙米具有与玉米相同的饲养效果和营养价值 ,以 50 %至 10 0 %的比例代替玉米是完全可行的     

Effect of Echinacea purpurea L. on oxidative status and meat quality in Arbor Acres broilers

BACKGROUND: Echinacea purpurea L. (EP) is a popular herbal antioxidant and immunomodulator. The present study was conducted to evaluate the effects of EP on meat quality and oxidative status in broilers. Two hundred and fifty (1‐day‐old) male broilers (Arbor Acres) were randomly allocated to five groups including the control (corn‐soybean meal diet) and 0.1, 0.5, 1.0 and 2.0% EP powder groups, with two replicates per treatment group. RESULTS: The results indicated that the addition of 0.5% and 1.0% EP significantly increased water‐holding capacity and decreased storage loss of breast and thigh fillets at 35 days old. For fillet colour, L* (lightness) values were lower, and a* (redness) and b* (yellowness) values were higher with EP supplementation. Lower crude fat contents were observed in EP groups in comparison with control at 35 days of age in breast and thigh fillets, respectively. Production of malondialdehyde was slightly reduced in serum of EP supplemented birds compared to the control group. Results for Trolox equivalent antioxidant capacity, catalase and superoxide dismutase were significantly higher for the 0.5, 1.0 and 2.0% EP supplemental groups than control group in serum. Liver and spleen tissues results showed that the antioxidative enzymes activities were higher with EP powder at 35 days of age. CONCLUSION: Dried EP can be used as a feed additive to improve the meat quality and oxidative status in Arbor Acres broilers. Copyright © 2012 Society of Chemical Industry     

Growth performance,nutrient digestibility and immune response of broiler chicks fed diets supplemented with a culture of Lactobacillus bulgaricus

BACKGROUND: Probiotics are being developed for use in animal feed to enhance production performance and prevention of gastrointestinal infections. The ban on using antibiotics as growth promoters, antibiotic resistance and the inherent problems of developing new vaccines make a compelling case for developing alternatives for in‐feed antibiotics. The alternatives of choice have to be considered under the environmental conditions of the animal. Among the probiotics in use today, Lactobacillus has been shown to play a vital role in disease prevention, immune enhancement, improved growth and carcass yield in poultry. The present study investigates the effect of Lactobacillus bulgaricus (LB)‐based probiotic on the growth performance, nutrient digestibility and immune response of broilers under tropical environmental conditions. RESULTS: Broilers fed LB diets consumed more feed (P < 0.05) and had greater body weight gain than the control group. Feed/gain ratio improved significantly (P < 0.05) with the 20, 40 and 60 mg kg^?1 LB diets compared with the control or 80 mg kg^?1 LB diet. The apparent digestibilities of nitrogen and fat increased with LB supplementation. However, there was no significant difference (P > 0.05) in fibre digestibility. White blood cell count increased significantly in broilers fed higher levels (>40 mg kg^?1) of LB compared with the control group. Antibody production measured as antibody titre against Newcastle disease vaccine showed a curvilinear response over the range of LB concentrations examined. CONCLUSION: The results indicate that LB addition to broiler chick diets significantly improved growth performance, increased nutrient digestibility and stimulated humoral immune response. Copyright © 2008 Society of Chemical Industry