不同阶段猪用颗粒饲料物理性能的对比分析   总被引：1，自引：0，他引：1       下载免费PDF全文

王进部  陈归园  王家乐  王雨  齐胜利 《中国猪业》2021,16(5):44-47

对某饲料厂不同阶段猪用4种颗粒饲料的物理性能包括直径、长度、硬度、容重、含粉率和耐久性指数（Pellet Durability Index, PDI）等进行测定,对结果进行归类总结并采用统计学的方法参照有关标准进行分析。结果表明,4种颗粒饲料直径在2.87~3.94 mm之间,母猪料直径最大,小猪料最小,两两之间差异显著（P<0.05）,而且随着猪只年龄的增加,颗粒饲料的直径呈递增趋势。颗粒长度在8.62~11.94 mm之间,以大猪料最长,小猪料最短,长径比偏高。颗粒硬度在3.86~6.47 kg之间,以大猪料最大,小猪料最小,中小猪料显著低于大猪料和母猪料（P<0.05）,只有小猪料符合有关要求。颗粒容重在576.7~614.6 g/L之间,母猪料最大,小猪料最小,两两之间差异显著（P<0.05）,与直径呈相同的增减趋势。含粉率以小猪料最大,且只有小猪料与大猪料之间差异显著（P<0.05）。颗粒PDI以大猪料最大,小猪料最小,各阶段猪料的含粉率和PDI均符合有关要求。建议饲料厂家注重颗粒饲料物理性能指标的控制,调整饲料配方和工艺参数,不断改进颗粒饲料的质量。  相似文献   

动物饲料国际贸易、养殖密度与环境氮磷平衡的关系     

王学鹏 《中国饲料》2021,(2):125-128

粮食和饲料的国际贸易促进了许多国家农业生产系统的专业化和集约化。专业化动物养殖越来越多地依赖进口大豆和玉米,虽然提高了动物生产力,但也促使作物和动物生产系统在空间上的分离。本文综述了几十年来全球范围内大豆和玉米的贸易变化,并将其与养殖密度和整个食品系统中营养平衡的变化联系起来。这一变化与不同的营养管理条例的差异和动物饲养密度的空间变化有关。深入解析这些变化有助于理解动物饲料国际贸易、养殖密度与氮磷平衡之间的复杂关系。  相似文献   

Compatibility of root growth and tuber production of potato cultivars with dynamic and static water‐saving irrigation managements          下载免费PDF全文

S. H. Ahmadi  M. Agharezaee  A. A. Kamgar‐Haghighi  A. R. Sepaskhah 《Soil Use and Management》2017,33(1):106-119

The important root characteristics of root length density (RLD) and root mass density (RMD) generally differ among irrigation managements and potato cultivars. The objective of this study was to investigate the RLD and RMD variations and their functional relationships with gross potato tuber yield for two commercial potato cultivars, Agria and Sante, under different irrigation strategies. Full irrigation and water‐saving irrigation strategies, deficit and partial root drying irrigations, were applied statically (S) and dynamically (D) based on daily crop evapotranspiration. Results showed that SPRD had significantly greater RLD (3.64 cm/cm³) and RMD (132.7 μg/cm³) than other irrigation treatments. Between the potato cultivars, Agria had significantly larger values of RLD (3.50 cm/cm³) and RMD (138.7 μg/cm³) than Sante. The functional relationship between the root growth characteristics and tuber yield showed that under water‐saving irrigations, Agria increased root mass at the expense of gross tuber yield but Sante increased root mass to maintain larger gross tuber yields. However, Agria produced more roots and gross tuber yield than Sante, and it is concluded that Agria is a more drought‐tolerant potato cultivar, which is recommended for tuber production in regions where water might be scarce. It was shown that larger root production in potatoes was associated with improved tolerance to water stress.  相似文献   

Evaluating the Response of Cobb MV × Cobb 500 Broilers to Varying Amino Acid Density Regimens for a Small Bird Program     

《The Journal of Applied Poultry Research》2019,28(4):943-962

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减氮条件下密度对望两优361产量的影响     

袁功平  胡兴年  张取仁  许有尊  汪谨桂 《现代农业科技》2019,(20)

为探索减氮条件下密度对望两优361产量的影响,2018年在马庙镇进行了该试验。试验结果表明：怀宁县单季稻施肥量应为：N:P:K=13.5:5.4:10.8。在此施肥量的基础上： 1.5万穴/667m_²为最佳移栽密度。  相似文献   

浅谈几种概率分布之间的相互关系     

孟凡华 《信阳农业高等专科学校学报》1992,(2)

本文简述了几种常用的概率分布之间的相互关系  相似文献   

Acoustic evaluation of the vertical distribution of dwarf ayu Plecoglossus altivelis altivelis in Lake Biwa     

Kunio Shirakihara  Masahiko Yoshida  Machiko Nishino  Yoshimi Takao  Kouichi Sawada 《Fisheries Science》2001,67(3):430-435

SUMMARY: The vertical distribution of dwarf ayu Plecoglossus altivelis altivelis in the pelagic waters of Lake Biwa was evaluated from June to September in 1995–97 from eight acoustic surveys using a quantitative echosounder. In each survey, echoes from a depth range of 3 m to the sea bottom were collected at a station every 2.7 s for 24 h together with measurements of vertical profiles of water temperature and chlorophyll-a. The ayu's echoes were identified using an underwater video camera. The ayu were observed near the maximum chlorophyll-a depth and above the thermocline. Their density was highest at depths of 4–11 m with 2–4 individuals/m ³ and was almost zero below 20 m. Echo signs were recorded as having a frequent duration of more than 1 h at night, whereas were of a shorter duration in the day. The fish stay in the epilimnion during the day without any clear vertical migration, but are distributed more uniformly at night. The advantages of remaining in the epilimnion are discussed in terms of food availability and predator avoidance.  相似文献   

Propagation techniques on root turion sprout browse ofPopulus davidiana Dode     

Xing Ya-juan  Wang Qing-gui  Wang Yan-he 《林业研究》2001,12(2):143-145

The root segments selected from dominant trees ofPopulus davidiana Dode were taken as reproductive material and were buried in different depths to carry out the reproduction of root turion sprout. The affecting factors of gemination rate, survival rate, and height growth for cutting wood of root sprout were comparatively analyzed. The results showed that the best suitable substrate for burying root is pearlite, with a germination rate of 15.16%. 3–4-cm root segments has the highest rate of germination (12.4%). The mixture of sand and soil (2∶1) is the best cutting substrate, with a survival rate of 81.3%, while as to height growth of cutting wood, the mixture of turfy and soil (1∶1) is the best. The cutting woods selected from different positions of stem show difference in height growth. The cutting wood from top stem is higher obviously than those from middle or low stem. Biography: XING Ya-juan (1969-), female, assistant researcher in Forest Research Institute of Heilongjiang Province, Harbin 150040, P. R. China. Responsible editor: Song Funan  相似文献   

中密度纤维板砂光机的改进及降耗   总被引：2，自引：0，他引：2  

谭飙崛 《木材工业》2001,15(5):33-34

笔者分析了中密度纤维板砂光机消耗较高、质量较差的原因，提出了改进措施。实施结果表明，砂光机运行正常，砂光产量和质量同步提高，消耗和成本下降，污染减轻。  相似文献   

东方杉温室大棚扦插育苗技术     

尹中明  吴文 《江苏林业科技》2009,36(5):44-45

东方杉系杉科属间杂交新树种,半常绿高大乔木,具有耐水湿、耐盐碱、生长速度快、景观效果好、抗风等优良特性;东方杉不结实,且无性繁殖困难。该文介绍了东方杉温室大棚扦插设施准备,采穗圃营建,扦插育苗方法等育苗技术。应用于大规模苗木生产,平均成活率达到76.3%。  相似文献