Trisodium phosphate dip,hot water dip,and combination dip with/without brushing on broiler carcass decontamination

The purpose of this research was to evaluate the effects of trisodium phosphate dip (TSP), hot water dip (HWD) and their combination dip with/without brushing on broiler breast skin for bacterial reduction and structural changes. Eviscerated broiler carcasses were obtained from a local slaughter plant and immediately subjected to one of six treatments: 1) two tap water dips at 25 °C (TWD/TWD), 2) TWD/TWD with brushing (TWD/TWD/B), 3) TWD and TSP at 8%/25 °C (TWD/TSP), 4) TWD and HWD at 71 °C (TWD/HWD), 5) TSP and HWD (TSP/HWD), and 6) TSP/HWD with brushing (TSP/HWD/B). Each dip was conducted for 45 s with or without brushing at 5 s on/off during the second dip. Compared to the control (TWD/TWD), TSP/HWD significantly reduced mesophilic aerobic bacteria (MAB), Escherichia coli (E. coli), and total coliforms by 1.1, 0.9 and 1.0 log CFU/g, respectively, and Salmonella prevalence by 53.3% (P < 0.05), whereas TWD/TSP and TWD/HWD showed intermediate reductions (P < 0.05). Upon brushing, TSP/HWD/B reduced populations of MAB, E. coli, and total coliforms, and the prevalence of Salmonella more effectively than control of brushing (TWD/TWD/B) (P < 0.05). When two sampling methods were compared, the method of stomaching released fewer MAB and total coliforms (named loosely-associated cells) than the grinding of the stomached skin (named tightly-associated cells). Compared to controls (TWD/TWD and TWD/TWD/B), both TSP/HWD and TSP/HWD/B generally resulted in darker, less reddish, and more yellowish breast skin. Scanning electron microscope and histological images indicated that both TSP/HWD and TSP/HWD/B had deeper skin penetration than controls or TWD/HWD and TWD/TSP. Overall, TSP/HWD/B showed the most effectiveness in broiler carcass decontamination.     

Development of a fungal pre‐treatment process for reduction of organic matter in contaminated soil

BACKGROUND: Combustion at high temperature is a common treatment method for heavily contaminated soils. The capacity of the combustion process is negatively correlated with organic matter content of the soil. Thus, by reducing the amount of soil organic matter, batch size could be increased and the combustion process improved. In this study, the possibility to pre‐treat soil containing high levels of organic matter with white‐rot and litter‐decomposing fungi was examined and scaled up. RESULTS: Calculations based on the CO₂ production in laboratory experiments indicated that 20% of the soil organic carbon would have been degraded in 6 months when treated with Sphaerobolus stellatus and 10% when treated with Stropharia rugosoannulata. In a pilot‐scale experiment with S. rugosoannulata mass loss due to degradation of soil organic matter accounted for 10% of the total weight of the soil in 6 months. CONCLUSION: A fungal pre‐treatment process for contaminated soils with high organic matter content was developed. Good results were obtained with S. stellatus and S. rugosoannulata and the process was successfully scaled up to 300 kg scale. Copyright © 2009 Society of Chemical Industry     

Comparative Capability to Detoxify Vegetable Allelochemicals by Larval Mosquitoes

In order to confirm the phytotoxicological basis for the ecological specialization of larval culicine fauna among different subalpine mosquito breeding sites, we compared the capability of six different Aedes larval taxa or populations of different ecological origin to detoxify dietary leaf litter originating from the environmental vegetation. Detoxification experiments were performed through in vitro digestion of a toxic leaf litter fraction using larval extracts as the enzymatic sources. Comparison of toxicological and detoxifying properties among the different larval samples indicates an association between their tolerance to leaf litter toxicants and their detoxification capability, which vary according to ecological origin. The fact that the detoxifying factor within the larval extracts appears to be a protein-like compound with a molecular weight bigger than 30 kDa suggests the possible involvement of detoxifying enzymes in larval tolerance to leaf litter toxicants. This is congruent with previous biochemical data that suggests the involvement of cytochrome P450 monooxygenase and esterase activities in the detoxification process.     

崇义客家梯田区森林枯落物持水特性

为了解崇义客家梯田水源区森林枯落物水文特性,进一步揭示森林的水源涵养功能,通过现场调查取样和室内实验分析等方法,对崇义客家梯田区森林枯落物的储量和持水率、持水量、吸水速率等持水特性进行了研究。结果表明:试验地各林分类型枯落物总厚度为3.0~8.6 cm,总储量为3.29~13.19 t/hm²,总储量整体上随总厚度的增加而增大;枯落物最大持水率为239.65%~343.54%,即枯落物最大吸持水量可达其干重的2.4~3.4倍,枯落物最大持水量为5.58~12.32 t/hm²,相当于0.56~1.23 mm的降雨水深;在浸泡开始2 h内,枯落物吸持水量增加较快,随着浸泡时间延长,持水量与吸水速率的变化均较为平缓,持水量与浸泡时间呈明显对数函数关系,吸水速率与浸泡时间呈明显幂函数关系。研究结果可为区域林分类型调配、森林涵养水源功能监测提供科学依据。     

酸枣仁油对热应激肉仔鸡生产性能及胴体品质的影响

研究酸枣仁油对肉仔鸡的抗热应激作用。结果表明:酸枣仁油对热应激肉仔鸡的平均日增重、平均日采食量和料重比均有改善作用,以15、25mg/kg添加水平最佳(P<0.01)。饲粮中添加25mg/kg酸枣仁油显著提高热应激肉仔鸡的屠宰率、半净膛率(P<0.05),添加25、50mg/kg酸枣仁油显著降低肉仔鸡皮下脂肪厚(P<0.05)。较理想的添加水平为25～50mg/kg。     

酵母硒对肉鸡组织硒含量及抗氧化能力的影响

试验选择108只1日龄健康AA肉仔鸡(公母混合),随机分为3组,每组3个重复,每重复12只鸡,对照组饲喂基础日粮,试验组A在对照组日粮基础上添加0.3mg/kg硒(亚硒酸钠),试验组B在对照组日粮基础上添加0.3mg/kg硒(酵母硒),饲养35d。通过检测试验鸡组织中硒含量和超氧化物酶活性及丙二醛含量,来研究酵母硒对肉鸡组织硒含量和抗氧化能力的影响。结果表明:酵母硒组鸡群的肌肉组织中硒含量显著高于对照组;与对照组相比,酵母硒和亚硒酸钠均可显著提高鸡群血液和组织中超氧化物歧化酶活性,显著降低丙二醛含量。     

Modulation of post-hatch growth and immunity through in ovo supplemented nutrients in broiler chickens

BACKGROUND: Early post‐hatch growth and immunity were assessed through in ovo supplementation of nutrients: amino acids (AA), trace elements (TE), fatty acids and vitamins (FAV) grouped under humoral immunity (HI) or cell‐mediated immunity (CMI) on the 18th day of incubation at the broad end of the egg using a 25 mm needle. RESULTS: Hatchability in AA groups was better than TE and FAV groups. CMI groups had better hatchability than HI groups. AA and TE groups had higher chick‐to‐egg weight ratio (P < 0.01) than the FAV group. At 3 weeks of age, a higher body weight (P < 0.01) was recorded in AA for CMI, TE for HI and FAV for HI groups. FAV‐injected chicks had a higher bursa weight at hatch, but TE chicks had higher thymus weight at the 3rd week of age. Humoral immune response was not different in in ovo injected chicks compared to control. CMI was higher (P < 0.01) in AA for CMI, TE for CMI and FAV for CMI or HI nutrient‐injected chicks. CONCLUSIONS: In ovo injection of AA for CMI and TE for HI may accelerate growth of broiler chickens. In ovo injection of AA, TE or FAV may modulate CMI in chicks. Copyright © 2011 Society of Chemical Industry     

饲养方式对AA鸡屠宰后胸脯肌肉和腿肌肉僵直过程理化特性的影响

目的 研究笼养和散养方式对AA鸡宰后24 h内胸脯肌肉和腿肌肉理化特性的影响。方法 随机选择同一批相同饲养水平散养和笼养的AA鸡各30只。按照商业屠宰方法屠宰后, 鸡胴体冰水冷却1.5 h, 然后, 4 ℃冷藏至宰后24 h。宰后0、3、6和24 h时取样, 分别测定pH值、肌糖原含量、肌节长度、R-值和肌原纤维小片化指数(MFI)。结果 笼养鸡比散养鸡活体重高8.17 %, 且笼养鸡体重较均一。在宰后僵直过程中笼养鸡胸脯肌肉和腿肌肉pH值和肌糖原含量降低速度分别比散养鸡快。笼养鸡胸脯肌肉进入僵直比散养鸡胸脯肌肉早, 但是笼养鸡腿肌肉进入僵直时间比散养鸡腿肌肉晚。笼养和散养鸡不管是胸脯肌肉之间, 还是腿肌肉之间, 其肌节长度和MFI之间没有显著差异。并且宰后24 h, 本实验所测定指标在笼养和散养鸡之间不存在显著差异。结论 饲养方式(笼养和散养)除了对AA鸡活体重以外, 对屠宰后胸脯肌肉和腿肌肉的理化特性没有显著影响。