Evaluation of pea proteins and poultry protein as fish meal alternatives in the diets for juvenile black sea bream,Acanthopagrus schlegelii

The potential of three different protein resources (pea protein isolate, PPI; pea protein concentrate, PPC; enzyme treated poultry protein, ETPP) as fish meal (FM) alternative protein in diets for juvenile black sea bream, Acanthopagrus schlegelii. (initial average weight 7.90 ± 0.13 g) was evaluated. Seven isonitrogenous and isoenergetic diets were formulated to replace FM at 0% (T0, control diet), 8% (designated as T1‐T3) and 16% (designated as T4‐T6) using PPI, PPC and ETPP respectively. Each diet was randomly assigned to triplicate groups of 25 juvenile fish for 8 weeks. At the end of the feeding period, survival rate was not significantly affected by dietary treatments. Growth performance in T6 (16% ETPP) group was significantly inferior to T0 group, however, weight gain and specific growth rate in other treatments showed no significant differences (P > 0.05). Mean feed intake, feed efficiency ratio and protein efficiency ratio were also poorer in fish fed in T6 than those of fish fed with the control diet respectively. Apparent digestibility coefficients (ADCs) of dry matter and crude protein for fish fed ETPP diets were significant lower than those of fish fed with the control diet, whereas ADCs of lipid were unaffected by dietary treatments. ADC's of dietary Leu, Ile, His and Lys was also significantly influenced. There were no marked variations in proximate compositions of dorsal muscle. With regard to plasma characteristics, significant difference was observed in triacylglycerol content. Ammonia concentration in plasma tended to increase in alternative protein diets as substitution level increased. There were significant differences in aspartate aminotransferase activities among groups, but alanine aminotransferase levels were unaffected by treatments. In conclusion, the present study demonstrated that PPI and PPC were potential protein sources for using in juvenile black sea bream diet. However, the substitution level of FM by ETPP should be limited within 16%.     

基于嗅觉可视化技术的猪肉新鲜度等级评判

利用嗅觉可视化技术对猪肉新鲜度等级进行评判.提取猪肉的挥发性气体与可视化传感器阵列进行反应,用图像处理技术分析反应前后传感器阵列的颜色变化,获取反映新鲜度的气味特征信息.通过主成分分析,选取前10个主成分作为所建立的BP神经网络的输入变量,构建猪肉新鲜度等级判别模型,模型的预测正确率为84.62％.研究结果表明:嗅觉可视化技术可用于猪肉新鲜度等级的快速评价.     

根系分区交替滴灌条件下葡萄根系分布特征及生长动态

采用原位取土法和根系生态监测系统连续两年研究了葡萄的根系空间分布和全生育期根系生长动态,结果表明:葡萄根系在水平方向主要分布在距离树干100 cm的范围内,占到总根系的80％以上,而且在径向方向呈指数衰减;葡萄根系在垂直方向主要分布在0～60 cm范围的土层内,占到总根系的75％以上.根系分区交替滴灌条件下干燥区与湿润区根系生长是不同的,葡萄的新生根系受到土壤水分条件的限制和自身生长的影响.在整个生育期,葡萄根系分区交替滴灌两侧根系生长均呈抛物线变化.     

洁蛋保鲜自动涂膜机

设计了用于洁蛋保鲜高效自动涂膜的洁蛋覆膜机,开发了控制系统,通过试验对设备的性能进行了验证.对电动机频率分别为5、10、15、20、25、30 Hz下的进蛋链条线速度和设备的处理量进行性能测试,验证了装置的实际生产能力.蛋壳表面干燥情况与覆膜状况的试验结果表明,在温度为25℃,相对湿度为60％,喷雾压力为0.6 MPa,单位时间喷雾量为43.6 mL/min,烘干机干燥能力为1.71 kJ/s时,最佳进蛋链条线速度为12.01 mm/s,处理量为4804颗/h,烘干机长度为50 cm,洁蛋干燥时间为4.16s.     

蝗虫对蓝光偏振光和非偏振光的定向响应对比

为给蝗虫灾害光电诱导捕集治理技术中蝗虫诱导光场性质的确定及不同光场的筛选组合提供理论支持,利用LED光谱色非偏振光、蓝光偏振光和行为反应试验装置,进行了不同光照特性的蓝光偏振光场和光谱色非偏振光场对蝗虫定向选择的对比试验,探讨了不同光场对蝗虫定向选择行为影响的机理.结果表明:蓝光偏振光条件下,蝗虫对光谱色非偏振光的趋光定向响应以紫光最优;蝗虫对偏振光和紫光的趋光定向响应对比中,蝗虫对线偏振光和紫光选择的对比率差别最小;蝗虫对偏振光的趋光定向响应取决于偏振光的光照强度,对非偏振光的趋光定向响应取决于光谱色和光照强度;蝗虫敏感光谱色光照强度和蓝光偏振光光照强度对蝗虫趋光响应敏感临界点的差别程度是影响其趋光定向响应选择差异的原因,但就光场光照性质而言,蝗虫敏感光谱色及其光照强度是提高蝗虫诱导率的关键因素.     

对东海区部分新增休渔作业方式的看法与建议

本文概述了东海区灯光嗣网、灯光敷刚、流刺网、蟹笼等捕捞作业的渔场、渔期及其渔业资源利用特点和生产状况,结合目前休渔效果的社会调研情况,综合分析了休渔的预期效果,提出了关于调整休渔时间的看法和建议。     

Dynamics of soil extractable carbon and nitrogen under different cover crop residues

Purpose

Cover crop residue is generally applied to improve soil quality and crop productivity. Improved understanding of dynamics of soil extractable organic carbon (EOC) and nitrogen (EON) under cover crops is useful for developing effective agronomic management and nitrogen (N) fertilization strategies.

Materials and methods

Dynamics of soil extractable inorganic and organic carbon (C) and N pools were investigated under six cover crop treatments, which included two legume crops (capello woolly pod vetch and field pea), three non-legume crops (wheat, Saia oat and Indian mustard), and a nil-crop control (CK) in southeastern Australia. Cover crops at anthesis were crimp-rolled onto the soil surface in October 2009. Soil and crop residue samples were taken over the periods October?CDecember (2009) and March?CMay (2010), respectively, to examine remaining crop residue biomass, soil NH₄ ⁺?N and NO₃ ^??CN as well as EOC and EON concentrations using extraction methods of 2?M KCl and hot water. Additionally, soil net N mineralization rates were measured for soil samples collected in May 2010.

Results and discussion

The CK treatment had the highest soil inorganic N (NH₄ ⁺?N?+?NO₃ ^??CN) at the sampling time in December 2009 but decreased greatly with sampling time. The cover crop treatments had greater soil EOC and EON concentrations than the CK treatment. However, no significant differences in soil NH₄ ⁺?N, NO₃ ^??CN, EOC, EON, and ratios of EOC to EON were found between the legume and non-legume cover crop treatments across the sampling times, which were supported by the similar results of soil net N mineralization rates among the treatments. Stepwise multiple regression analyses indicated that soil EOC in the hot water extracts was mainly affected by soil total C (R ²?=?0.654, P?<?0.001), while the crop residue biomass determined soil EON in the hot water extracts (R ²?=?0.591, P?<?0.001).

Conclusions

The cover crop treatments had lower loss of soil inorganic N compared with the CK treatment across the sampling times. The legume and non-legume cover crop treatments did not significantly differ in soil EOC and EON pools across the sampling times. In addition, the decomposition of cover crop residues had more influence on soil EON than the decomposition of soil organic matter (SOM), which indicated less N fertilization under cover crop residues. On the other hand, the decomposition of SOM exerted more influence on soil EOC across the sampling times among the treatments, implying different C and N cycling under cover crops.     

绍兴市农业生态和农业气象灾害监测预警系统

通过建立基于3S技术的农业生态监测和基于自动气象站、雷达、卫星、数值预报、短信息技术的农业气象灾害监测预警系统,动态监测绍兴市耕地被侵占面积,分析水资源分布、土地利用覆盖等农业自然资源分布特征,并对农业气象灾害实现监测和预警,从而为根据当地自然资源优势,通过农业结构调整,有效地减轻气象灾害损失,促进农业可持续发展提供技术支撑。     

滩地造林抑螺作用机理研究进展

长江流域滩地是我国钉螺分布的主要区域,也是血吸虫病的主要流行区。近些年我国大力实施的林业血防工程通过滩地营造人工杨树林,使得钉螺原有孳生地的多种生物要素和非生物要素发生了明显变化,显著减少了钉螺种群的分布空间,从而有效控制了血吸虫病的传播。目前,国内外在滩地造林后单一要素改变对钉螺的影响方面已有较多研究,但有关生物要素与非生物要素对钉螺分布的交互作用还未有深入探索,对钉螺孳生产生抑制作用的关键要素尚不明确。文中综述了滩地造林后林下的草本植物群落、土壤理化性质、光照、地温等诸多要素发生变化对钉螺生存的不利影响,总结了滩地造林抑螺作用机理的研究进展,提出该领域今后的重点研究方向,以期为滩地造林抑螺作用机理的深入研究提供参考和借鉴。     

马尾松毛虫的主要防治措施

浙江省龙泉市植物资源极其丰富,有松木林面积4.66万hm2,马尾松毛虫是为害马尾松林的大敌,防控马尾松毛虫发生为害任务十分艰巨。