我国化肥的需求价格弹性分析   总被引：1，自引：0，他引：1  

王侃  汪波 《中国农机化》2007,(5):31-33

化肥在农作物的生长中起着举足轻重的作用,但它以石油、天然气和煤炭等为原料,是高耗能产业。随着国家鼓励农民种田,种植面积不断扩大,对化肥的需求也同步增加。自2003年以来,全球化肥价格持续上扬,我国化肥价格也不断上涨。本文对2001～2005年主要化肥产品的需求价格弹性的进行分析,目的是想深入了解化肥的供求特征、弹性特征和波动规律,为政府相关部门制定产业政策和行业管理办法提供依据。  相似文献   

摘锭式采棉机配套残膜分离试验装置设计   总被引：1，自引：0，他引：1  

李晓良  丁竹青  张若宇  坎杂  李硕  金作徽 《农机化研究》2015,(10):98-102

新疆棉花采用地膜覆盖的种植模式,在机械化采收过程中混入部分残膜,降低了机采籽棉质量等级。为了能够从源头上消除机械化采收过程中带入的残膜,采用正压风力和网状滚筒相结合的方式设计了适合于摘锭式采棉机的籽棉残膜分离机。为此,阐述了残膜分离机整体结构、结构参数、工作原理和各组成部分的设计。通过仿真分析对样机进行了优化,对优化后的残膜分离机进行过试验验证。结果表明:该机设计生产率平均达到336kg/h,残膜分离率平均能够达到68.91%。  相似文献   

奶牛性控精液应用效果简析     

阚远征  张振山 《中国奶牛》2007,(5):23-24

本文通过性控精液应用试验，分类统计了青年牛、成母牛在三种不同输精方式下的情期受胎率，母犊牛的出生比例，结果表明选用青年母牛“1次1支”的配种方式比较经济实用。  相似文献   

奶牛乳房炎引发的经济损失   总被引：1，自引：0，他引：1  

阚远征 《乳业科学与技术》2006,28(2):93-94

乳房炎是奶牛的常见疾病之一，对奶牛生产的危害性很大。乳房炎的感染途径通常是经由乳头口侵入或通过血液、淋巴感染，常由挤奶技术不熟练、奶挤不净、乳房不洁以及乳房、乳头外伤受到细菌感染而引起。另外，结核病、口蹄疫、子宫炎等也可继发。乳房炎会影响牛只的健康，并降低经济收入。目前全世界约有2．2亿头奶牛，其中约有1／3的奶牛患有各种类刊的乳房炎，每年因乳房炎造成的损失高达3000亿元人民币。  相似文献   

Meiotic maturation of bovine oocytes in vitro: improvement of meiotic competence by dibutyryl cyclic adenosine 3',5'-monophosphate     

E Sato  M Matsuo  H Miyamoto 《Journal of animal science》1990,68(4):1182-1187

The present study was undertaken to determine the precise stage of growth at which the ability to resume meiosis is acquired in bovine oocytes. Oocytes of various sizes were isolated from ovaries by mechanical dissection using an 18-gauge needle followed by a razor blade. This method yielded an average of 26.2 +/- 7.4 growing and fully grown oocytes from an ovary. Cumulus-enclosed oocytes were cultured in vitro in tissue culture medium 199 containing 10% fetal calf serum. Oocytes less than or equal to 90 microns in diameter did not resume meiosis. However, germinal vesicle breakdown was observed in oocytes whose diameters exceeded 91 microns. Polar body formation was observed in oocytes with diameters exceeding 101 microns. About 80% of the oocytes with diameters greater than or equal to 121 microns were able to extrude the polar body. The percentage of large oocytes (101 to 120 microns) with first polar body increased when incubated in medium containing dibutyryl cyclic adenosine 3',5'-monophosphate; however, oocytes 90 to 101 microns did not extrude the first polar body even when cultured in a medium containing dibutyryl cyclic adenosine 3',5'-monophosphate. These observations indicate that the capability to resume meiosis is acquired gradually during development of oocytes and that dibutyryl cyclic adenosine 3',5'-monophosphate can improve the meiotic competence of bovine oocytes in culture.  相似文献   

A study on the effect of electrical stimulation on living tissue: potential before, during and after galvanization with constant current of 20 microA through platinum electrodes     

T Kubota  K Sato 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1990,52(2):315-319

Two platinum needles (therapeutic electrode) were inserted into the rabbit's auricle, and with the medial angle of the eye as the datum point of measurement, the electric potential was measured before, during, and after the galvanization with micro-current (20 microA). With the insertion of the needles alone, the potential between the needles and the datum point showed -0.10 to +0.28 V, which gradually decreased thereafter to reach stable levels ranging from -0.02 to +0.17 V in 3 or 4 days. When galvanized, the potential stood +0.75 to +1.30 V between the anode and the datum point, and -0.37 to -0.50 V between the cathode and the datum point. Then, 3 days later, the voltage rose +1.40 to +1.65V between the anode and the datum point, and went down -0.60 to -0.85 V between the cathode and the datum point. When the micro-current was switched off, the potential immediately decreased, and slight potential endured after 24 hrs. These findings revealed that the insertion of needles generated electric potentials, that galvanization charged the tissue, and that cessation of stimulation led to storage and discharge of electricity.  相似文献   

Inhibition of germinal vesicle breakdown of isolated cumulus-free mouse oocytes in culture by a calcium inhibitor, TMB-8.     

E Sato 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》1992,54(3):605-607

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Experimental atrophic rhinitis in 2 and 4 month old pigs infected sequentially with Bordetella bronchiseptica and toxigenic type D Pasteurella multocida.     

T Sakano  M Okada  A Taneda  M Ono  S Sato 《Veterinary microbiology》1992,31(2-3):197-206

Experimental infections with Bordetella bronchiseptica and/or toxigenic type D Pasteurella multocida were studied in 2- and 4-month-old primary specific-pathogen-free pigs. None of the 2-month-old pigs inoculated with B. bronchiseptica or P. multocida alone developed turbinate atrophy. All the pigs inoculated with B. bronchiseptica (10(7) CFU/head) and P. multocida (10(9) CFU/head for 5 consecutive days) together, however, developed clinical and post-mortem signs of atrophic rhinitis (AR) similar to the naturally occurring disease. Slight to severe turbinate atrophy was observed in the 4-month-old pigs inoculated with B. bronchiseptica and P. multocida (at the same concentration as above) at necropsy.  相似文献   

Detection of bovine antibodies to the outer membrane of ruminal Bacteroides succinogenes by enzyme-linked immunosorbent assay (ELISA)     

S Sato  K Ogimoto  Y Nakai 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1990,52(1):29-34

The enzyme-linked immunosorbent assay (ELISA) was used to detect bovine serum antibodies directed to the outer membrane antigen of a ruminal bacteria, Bacteroides succinogenes. The outer membrane antigen of B. succinogenes was highly reactive against homologous antiserum, compared with rabbit sera raised against B. ruminicola subsp. ruminicola, B. ruminicola subsp. brevis and Selenomonas ruminantium. The titers of sera from colostrum-deprived calves were negligible level, while those of sera from colostrum-fed calves were relatively high. The mean titer of sera from 10 day-old calves was significantly (p less than 0.01) higher than that of 40 day-old calves, and was significantly (p less than 0.01) lower than that of adult cattle. The mean titer of sera from dairy cows which fed high-roughage diet was higher than that of feedlot cattle which fed high-concentrate diet. These results suggest that the antibodies against the outer membrane antigen of B. succinogenes transfer to calves via the colostrum, and that the titers of cows are affected by the way of feed management.  相似文献   

Effects of dietary spirulina on meat colour in muscle of broiler chickens.   总被引：5，自引：0，他引：5  

M Toyomizu  K Sato  H Taroda  T Kato  Y Akiba 《British poultry science》2001,42(2):197-202

1. The present study was undertaken to determine the effects of dietary spirulina on growth performance and pigmentation in the muscle of growing broiler chickens and to examine the possibility that zeaxanthin in spirulina may affect yellow colour development in the meat. 2. Twenty-four, 21-d-old, male broiler chicks were fed an experimental diet containing spirulina at 0, 40, or 80 g/ kg for 16 d. No significant differences among treatments were observed in body weights, nor weights or yields (as a percentage of body weight) for any of the selected traits, including liver, abdominal fat, kidney and Pectoralis profundus. 3. Spectrocolourimetric analyses revealed that the redness of Pectoralis superficialis, profundus and Sartorius muscles reached a maximum in chicks fed the 40 g/kg spirulina diet, while the yellowness of all fillets, including the Semitendinosus muscle, increased in a sub-linear fashion with increased spirulina in the diet. The overall correlation between the yellowness and zeaxanthin content in the Pectoralis muscle was significant. 4. This study provides the first conclusive evidence that dietary spirulina influences both the yellowness and redness of broiler flesh and that the increments in yellowness with dietary spirulina content may possibly be reflected in the common yellow pigment related to the accumulation of zeaxanthin within the flesh.  相似文献