浅谈蛋鸡开产体重对生产性能的影响   总被引：3，自引：0，他引：3  

吴忻 《中国家禽》2005,27(15):44-45

1、产蛋高峰短而低的问题。当养殖户遇到产蛋高峰不高或高峰上去后，又很快下降的问题时，往往将问题归咎到种鸡或饲料上，其实除了上面的问题外，还有一个重要的问题被忽视，这就是开产前的体重问题。根据国外各个品种的饲养要求，正常的鸡群在6周龄平均体重应达到标准上限或超标10％，均匀度达到90％以上；12周龄平均体重达标即可，均匀度应在85％以上；18周龄平均体重应达标或超标，均匀度达到80％以上。  相似文献   

一种利用制冷机产生的副热生产热水的技术     

辛守帅  刘迎春 《中国奶牛》2005,(6):52-53

为了保持牛奶的新鲜程度,防止牛奶变酸和细菌数升高,各个规模牛场和收奶站均配备了牛奶冷却设备,同时还需要通过锅炉或电加热等方式生产大量的热水来清洗设备。利用锅炉或电加热生产热水不但浪费了大量的财力、物力和人力,还造成了环境污染。现介绍一种不额外消耗能源解决热水供应的方法,供大家参考。1原理冷冻机在制冷的同时,产生大于制冷量的热量。压缩机高压出来的温度一般超过90℃以上,这部分热量一般经过风冷的方式通过散热器散发到室外。特别是夏天,气温较高,散热器散热效率较低,需要浪费大量的冷却水冷却,即使这样,有时温度还是降不…  相似文献   

Comparison of morphology, viability, and function between blood and milk neutrophils from peak lactating goats          下载免费PDF全文

Sui Zhi Tian  Chai Ju Chang  Chih Chi Chiang  Huo Cheng Peh  Mu Chiou Huang  Jai-Wei Lee    Xin Zhao 《Canadian journal of veterinary research》2005,69(1):39-45

The morphological features of blood and milk neutrophils from peak lactating goats were compared using light microscopy, scanning electron microscopy and flow cytometry in order to investigate the cytological changes of neutrophils after migration into the mammary gland. The kinetics of reactive oxygen intermediates (ROI) generation and gelatinase release of blood and milk neutrophils, with or without stimulation of phorbol 12-myristate, 13-acetate ester (PMA), were used to characterize their responses to inflammatory stimuli. Neutrophils isolated from goat milk were highly segmented and contained multi-lobed nuclei. Ultrastructurally, milk neutrophils were more ruffled on the surface compared to blood neutrophils. Approximately 30% of milk neutrophils were undergoing cell death, either necrosis or apoptosis, in contrast to 8% of blood neutrophils. The ROI production of activated milk neutrophils peaked earlier than blood neutrophils, but the duration and the intensity were much less. Neutrophils from both sources augmented the release of gelatinase in response to PMA (1 ng/mL). However, the amount of gelatinase released from milk neutrophils was lower (P < 0.05) than that of blood neutrophils. In summary, more neutrophils become apoptotic and necrotic in the mammary gland, presumably due to spontaneous aging, the process of diapedesis, and the interaction with milk components. Milk neutrophils have impaired functionalities in comparison with blood neutrophils. The information is relevant when studying mammary gland immunity and related diseases, such as mastitis.  相似文献   

宁夏春小麦磷素利用效率的基因型差异研究   总被引：4，自引：0，他引：4  

何文寿 《干旱地区农业研究》2003,21(2):1-6

在不同施磷土壤条件下,采用肥料田间试验和测试分析方法,研究了宁夏春小麦磷素利用效率及其有关性状的基因型差异。结果表明,不论施磷与否,小麦籽粒产量、生物学产量、磷肥增产率、地上部茎叶和籽粒中含磷量以及磷素吸收累积量、磷素利用效率等均存在明显基因型差异,且这种差异在低磷条件下更为明显。在低磷条件下,籽粒生产中的磷素利用效率变化在160.1～448.3kg/kg之间,平均为223.1kg/kg,变异系数为23.05％;干物质生产中的磷素利用效率变化在332.6～898.5kg/kg之间,平均为458.4kg/kg,变异系数为22.57％。从中筛选出低磷高产高效品种8个。在较高供磷条件下,籽粒生产中的磷素利用效率变化在150.9～350.9kg/kg之间,平均为229.8kg/kg,变异系数为20.63％;于物质生产中的成素利用效率变化在358.3～746.5 kg/kg之间,平均为482.Ikg地,变异系数为 18.76％。从中筛选出高磷高产高效品种7个。通过相关分析,研究了不同供成条件下磷素利用效率与其它营养性状之间的关系,提出了培育磷高效品种的有用性状指标。  相似文献   

Mast cell tryptase and asthma     

NIU Qing-xia  HE Shao-heng 《园艺学报》2003,19(8):1125-1128

As an important mediator of allergic inflammation, mast cell tryptase is involved in the in duction of hypersensitivity, infiltration of inflammatory cel s and t issue remodeling in respiratory tract.The effects of tryptase inhibitors on the actions of tryptase show further the potential of tryptase in the pathogenesis of asthma and its inhibitors in the treatment of asthma.  相似文献   

Bcl-2 antisense oligodeoxynucleotide increases the sensitivity of HL60 and K562 cells to daunorubicin     

LEI Xiao-yong  ZHANG Huan  HE Dong-mei 《园艺学报》2003,19(2):194-197

AIM:To investigate whether the bcl-2 antisense oligonucleotide increases the sensitivity of HL60 and K562 cell lines to daunorubicin.METHODS:IC50 for HL60 and K562 was determined with MTT method, the expression levels of Bcl-2 protein were assayed by immunofluorescence using fluoresce isothiocyanate labeling. In addition, apoptosis was detected by morphological observation and flow cytometric analysis of DNA fragmentation.RESULTS:It was found that the two oligonucleotides directed against the coding region and the translation initiation of bcl-2 mRNA, combined respectively with daunorubicin, inhibited expression of bcl-2 protein, increased apoptosis in HL60 and K562 cells, and decreased IC50 of daunorubicin significantly (P＜0.05). Compared to the antisense oligonucleotide directed against the translation initiation of bcl-2 mRNA, the antisense oligonucleotide directed against the coding region showed stronger effects in the aspects of increasing the sensitivity of HL60 cells to daunorubicin (P＜0.05).CONCLUSIONS:These two antisense sequences in the translation initiation and the coding region of bcl-2 mRNA increased the sensitivity of HL60 and K562 cell lines to daunorubicin in a sequence-specific manner.  相似文献   

Effect of Liucha extract on tumor K562 cell growth     

LIU Xin  PAN Xing-bin  LI Xing-yu 《园艺学报》2003,19(2):253-255

AIM:To investigate the effects of Liucha extract on the growth of tumor cells in vitro and its possible mechanism.METHODS:The capability of colony forming of human leukemia K562 cell in vitro and the cells metabolism were studied by semi-solid agar culture and MTT staining. Then , the changes in morphology in the tumor cells were examined using electronic microscope.RESULTS:Semi-solid agar culture and MTT colorimetric analysis showed that Liucha extrats could significantly inhibit the growth of the tumor cells and their capability of colony forming. Also,under the electronic microscope,it was found that the tumor K562 cell had a narrower perinuclear space,condensation of chromatin and an enlarged mitochondria , in which the cristase disappeared.CONCLUSION:The extract from Liucha possesses an inhibitory effect on K562 cell growth in vitro through affecting the metabolism of the tumor cells.  相似文献   

Selection and amplification of the liver stem cell subset from rat bone marrow cells with a medium containing cholestatic serum in vitro     

CAI Yun-feng  MIN Jun  FANG Tian-ling  CHU Zhong-hua  DENG Xiao-geng  HE Jing-song  CHEN Ji-sheng 《园艺学报》2003,19(8):1029-1033

AIM: To explore the feasibility of direct separat and selective enlargement of the bone marrow-derived liver stem cells (BDLSC) from bone marrow cells with a culture system containing cholestatic serum in vitro. METHODS: Bone marrow cells of rats were cultured with selective media containing 2%, 5%, 7% and 10% cholestatic rat serum, respectively. The BDLSC were then induced to proliferate with the addition of hepatocyte growth factor (HGF) on the firth day. BDLSC were characterized using immunocytochemistry and RT-PCR for lineage markers, glycogen staining and urea synthetic assay for functions 2 weeks later. RESULTS: Bone marrow cells were unble to form colony in the presence of 2% cholestatic serum and apopotosis appeared gradually in 7% or 10% cholestatic serum. The BDLSC survived in the medium containing 5% cholestatic serum while the other types of cells did not. The survival cells proliferated with a high speed during the second week and then formed hepatocyte-like colony-forming units (H-CFU). Cells in the H-CFU expressed the characteristic proteins of fetal hepatocytes. Furthermore, they had glycogen storage and urea synthesis functions, two of the critical features of hepatocytes. CONCLUSION: The selective micro-environment effectively selected BDLSC from the bone marrow cell, and will be a new way to provide an abundant source of donor hepatocytes for clinical cell therapy.  相似文献   

Effect of adenosine on myocardial expression of TNF-α, IL-6 mRNA in rats with pneumonia     

TAN Jian-xin  HUANG Yu-ge  HUANG Xiu-lan  HE Hui-juan  ZHAO Jia-ming 《园艺学报》2003,19(10):1403-1406

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20%多效唑·甲哌 FEE7 微乳剂防止小麦倒伏和增产机理研究   总被引：1，自引：0，他引：1  

段留生  李召虎  何钟佩  刁家连  田晓莉  王保民  贾敬业 《农药学学报》2002,4(4):33-39

冬小麦二棱期喷施植物生长调节剂20%多效唑·甲哌鎓微乳剂375 mL/hm2,可以显著抑制茎秆基部节间伸长,增加各节间充实度,其中赤霉素(Gas)和生长素(IAA)降低,可显著增强小麦抗倒伏能力和降低田间倒伏率.处理还协调了穗数、穗粒数和粒重的关系,增产幅度6.2%～28.6%.增产原因可能在于促进籽粒灌浆强,增加籽粒中内源Gas、IAA、细胞分裂素(CTKs)的水平,增强了籽粒库活性,同时促进茎叶中干物质向籽粒运转.  相似文献