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61.
1. Four experiments with growing broiler chickens were carried out to study the effects of the inclusion in their diets of lupin (Lupinus angustifolius ) seed meal on E. coli and lactobacilli counts in crop, ileum and caeca at 3 or 4 weeks of age. 2. Diets were formulated to contain the same amounts of metabolisable energy (12.55 MJ/kg) and protein (210 g/kg). Raw whole (heat-untreated) or dehulled sweet (low in alkaloids) lupin seed meal (400 and 320 g/kg respectively) were used to prepare the lupin-based diets, whose protein content was completed with either defatted soyabean meal or casein. 3. Final body weight and food intake of chickens fed on whole lupin seed meal diets were lower than controls, but gain: food ratios were not different. However, birds given the diet with dehulled lupin seed meal had similar body weight, food intake and gain: food values as those of controls. 4. While E. coli counts were not affected, lactobacilli numbers were consistently increased compared to controls in all intestinal sections of chickens fed on the whole or dehulled lupin-based diets, irrespective of the age of the birds or the presence of soyabean meal or casein in the diet. The lactobacilli species isolated were: Lactobacillus fermentum, L. acidophilus, L. salivarius and L. brevis 5. The results suggest that the use of whole or dehulled sweet lupin seed meal in diets for growing broilers might enhance the growth of lactic acid-fermenting bacteria in the gut.  相似文献   
62.
This study was aimed to evaluate the reproductive performance of rabbit does artificially inseminated (AI) with a GnRH analogue [des‐Gly10, d ‐Ala6]‐LHRH. ethylamide to induce ovulation by intravaginal administration, delivered in the seminal dose. In a preliminary experiment, 39 does were divided into three groups (n = 13) that, at the time of AI, received the following ovulation induction treatments: (i) control group: 20 μg of gonadorelin administered intramuscularly; (ii) 25 μg of the GnRH analogue added to the seminal dose; (iii) 30 μg of the GnRH analogue added to the seminal dose. Fertility did not differ between the three groups (control: 80.6%, group 2: 82.8%, group 3: 73.3%). In a second experiment, a large‐scale field trial was conducted to test the use of 25 μg of the GnRH analogue [des‐Gly10, d ‐Ala6]‐LHRH ethylamide delivered in the seminal dose (n = 270) against 20 μg of gonadorelin administered intramuscularly. Fertility was higher (p < 0.05) when ovulation was induced by intravaginal administration of the GnRH agonist (91.1% vs 85.6%). Prolificacy or mortality at birth was never affected by the ovulation induction treatments. In a third experiment, two groups of does [control group (n = 39): ovulation was induced using 20 μg of gonadorelin administered intramuscularly; treatment group (n = 40): ovulation was induced using 25 μg of [(des‐Gly10, d ‐Ala6)‐LHRH ethylamide added to the seminal dose] were inseminated at 42‐day intervals for five successive AI cycles, to test the response to the GnRH agonist after repeated intravaginal administration to the same animals. Fertility and prolificacy were not influenced by the ovulation induction treatment neither there was an interaction between treatment and parity. The last experiment was aimed to determine whether it could be possible to add the GnRH agonist to the semen in the AI Center, just after semen collection and dilution, or it would have to be added in the farm, immediately before AI. Kindling rates did not significantly differ when ovulation was induced by intramuscular injection of gonadorelin (84.5%) or when the GnRH agonist was added to the seminal dose just at the moment (93.8 %) or 24 h before AI (90.4 %), but it was significantly lower when the hormone was added to the semen 32 h before AI (76.3 %). Prolificacy, however, was not influenced by the ovulation induction treatment.  相似文献   
63.
64.
Prognostic significance of tumor histology and four computed tomography (CT) staging methods was tested retrospectively in dogs from three treatment centers that underwent intent-to-cure-radiotherapy for intranasal neoplasia. Disease-free and overall survival times were available for 94 dogs. A grouping of anaplastic, squamous cell, and undifferentiated carcinomas had a significantly shorter median disease-free survival (4.4 mo) than a grouping of all sarcomas (10.6 months). Disease-free survivals were not significantly different, when all carcinomas were compared with all sarcomas. The published original and modified WHO staging methods did not significantly relate to either survival endpoint. A modified human maxillary tumor staging system previously applied to canine nasal tumors was prognostically significant for both survival endpoints; a further modified version of that CT-based staging system resulted in improved significance for both survival endpoints. Dogs with unilateral intranasal involvement without bone destruction beyond the turbinates on CT, had longest median survival (23.4 months); CT evidence of cribriform plate involvement was associated with shortest median survival (6.7 months). Combining CT and histology statistically improved prognostic significance for both survival endpoints over the proposed CT staging method alone. Significance was lost when CT stages were collapsed to 相似文献   
65.
西藏玛旁雍错流域湖泊面积变化及成因分析   总被引:5,自引:0,他引:5  
利用1975年地形图、1990年、1999-2009年TM卫星遥感影像和近35 a(1975-2009年)气温、降水、积雪日数、蒸发量等气候资料,分析研究了位于西藏阿里地区南部普兰县境内玛旁雍错、拉昂错湖泊面积变化对气候变化的响应。结果表明:在过去35 a里玛旁雍错、拉昂错面积先减少后增加,总体呈减小趋势,到2009年玛旁雍错面积为415.44 km2,拉昂错面积为261.36 km2。与1975年相比2个湖泊面积分别减少了1.56 km2和11.01 km2;受气候变暖的影响,流域附近的冰川面积也在加速退缩。对1975-2009年普兰县气象资料统计分析可知,降水量减少是导致湖泊面积缩小的主要原因,蒸发量不显著的增加及雪冰消融也是近几年湖泊面积波动变化的原因之一。  相似文献   
66.
In the subtropical highlands of Central Mexico, where the main crop is maize (Zea mays), the conventional practice (CP) involves tillage, monoculture and residue removal, leading to soil degradation and unsustainable use of natural resources and agricultural inputs. Conservation agriculture (CA) has been proposed as a viable alternative in the region, based on reduction in tillage, retention of adequate levels of crop residues and soil surface cover and use of crop rotation. This study began in 2009 when the highlands of Central Mexico suffered from a prolonged drought during vegetative maize growth in July-August, providing an opportunity for the on-farm comparison of CA with CP under severe drought conditions which 21 climate change models projected to become more frequent. Under dry conditions, CA resulted in higher yields and net returns per hectare as early as the first and second years after adoption by farmers. As an average of 27 plots under farmers' management in 2009, the maize yields were 26% higher under CA (6.3 t ha-1) than under CP (5.0 t ha-l). 2010 was close to a normal year in terms of rainfall so yields were higher than in 2009 for both practices; in addition, the yield difference between the practices was reduced to 19% (6.8 t ha-1 for CA vs. 5.7 t ha-1 for CP). When all the 2009 and 2010 observations were analyzed in a modified stability analysis, CA had an overall positive effect of 3 838 Mexican Pesos ha-1 (320 $US ha-1) on net return and 1.3 t ha-1 on yield. After only one to two years of adoption by farmers on their fields, CA had higher yields and net returns under dry conditions that were even drier than those predicted by the analyzed 21 climate change models under a climate change scenario, emission scenario A2.  相似文献   
67.
Des travaux antérieurs ayant permis de démontrer que des souches non pathogènes de Fusarium sont impliquèes dans les mécanismes de résistance des sols aux fusarioses, nous avons tenté d'utiliser des souches de Fusarium sélectionnées pour lutter contre ces maladies. Les bons résultats obtenus en conditions expérimentales nous ont conduits à mettre en place un réseau d'expérimentation en conditions normales de culture dans des serres de production de tomates et de melons. Le premier problème à résoudre est celui de la production massive d'inoculum, de sa conservation et de son introduction dans les sols et substrats de cultures. La production de l'inoculum est réalisée en fermenteur, les propagules produites soni récupérées par filtration et mélangées avec du talc, support inerte qui après avoir été séché assure la conservation et la distribution de cet inoculum dans des conditions satisfaisantes. Les quantités d'inoculum produites en 1985–86 ont permis de réaliser plusieurs essais de lutte dans des conditions normales de production. L'inoculum protecteur est apporté, soit dans les substrats de culture hors sol au moment de leur ensachage, soit dans les sols en place, immédiatement après leur désinfection au bromure de méthyle. L'installation de la souche protectrice est suivie régulièrement grace à des analyses microbiologiques et la gravité de la maladie est notée régulièrement en cours de culture. Les résultats enregistrés en 1986, variables d'une situation à l'autre, ne permettent pas de porter un jugement définif sur l'intéret de ce procédé de lutte. Ils sont cependant intéressants et permettent d'organiser sur des bases plus solides notre campagne d'expérimentation 1986–87.  相似文献   
68.
目的对奶牛温氏支原体16SrRNA基因进行PCR扩增及克隆分析。方法从自然感染体的广西奶牛无菌采集血液,分离温氏支原体并提取病原基因组,用血营养菌的16SrRNA基因的通用引物进行PCR扩增,将扩增产物克隆到PGEM-Teasy载体后进行溺,I序和分析,并与Genebank上搜索的温氏支原体相应序列进行比较,建立系统发育树。结果PCR扩增得到长约1.5kb的扩增片段,测序结果显示该片段全长为1453bp,同源性分析表明该序列与Neimark公布的温氏支原体(前称温氏附红细胞体)(AF016546)的16SrRNA基因序列同源性达到97.4%,与系统发育进化树表明本株温氏支原体同本地株的关系较近,而与国外株的新缘关系较远。国内公布的广西株同源性为99.8%。结论结果表明证实该病原为温氏支原体,从分子生物学水平证实了温氏支原体在广西的存在。由于本试验分离得到的牛温氏支原体与国外发表的牛温氏支原体核苷酸序列相差2.6%,因此两者的基因型存在一定的差异,这对该病的分子流行病学分析具有一定的意义。  相似文献   
69.
为探明不同基质对大根报春苣苔(Primulina macrorhiza)叶插繁殖的影响,以大根报春苣苔的全叶片为试验材料,采用正交试验设计,研究泥炭、珍珠岩、蛭石、稻壳炭4种基质对叶片扦插成活率、子株数、新叶总数的影响,并筛选出最优组合。结果表明,在试验的9个处理中,扦插基质以泥炭∶珍珠岩∶蛭石∶稻壳炭为4∶2∶2∶1(体积比)为佳。泥炭对成活率、子株数、新叶总数均有显著影响(P0.05);珍珠岩对成活率、子株数、新叶总数均无显著影响(P0.05);蛭石仅对新叶总数有显著影响(P0.05);稻壳炭仅对子株数有显著影响(P0.05)。正交分析并推理出,以4种成分为扦插基质时,泥炭、珍珠岩、蛭石和稻壳炭的最佳配比为2∶1∶1∶1(体积比)。  相似文献   
70.
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