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1.
Two open-circuit respiration chambers for small animals (rats, poultry and rabbits) have been built at the Estación Experimental del Zaidín. The respiration facility is air-conditioned, the temperature and the relative humidity in the chambers can be regulated from about +15 to +30 degrees C and from 60 to 90%, respectively. The air flow is determined by the differential pressure principle, CO2 measurement is by the infra-red technique and O2 analyser is of the paramagnetic type. The present work describes the technical details of the respiration plant and the calibration procedures of the whole system. 相似文献
2.
内蒙古不同草原类型土壤呼吸对放牧强度及水热因子的响应 总被引：2，自引：0，他引：2
土壤呼吸的测定对于预测不同生态系统碳收支起着关键性作用。本研究利用Li-8100开路式碳通量测定系统,对内蒙古荒漠草原、典型草原和草甸草原生态系统在不同放牧强度(零放牧的对照、轻度放牧、中度放牧和重度放牧)下土壤呼吸速率进行测定,并分析了土壤呼吸与土壤温度(10 cm处)和空气相对湿度的相关性。结果表明,草地类型、放牧强度及它们的交互作用都对土壤呼吸有显著影响(P<0.05),放牧强度对土壤呼吸的影响主要表现在荒漠草原和典型草原生态系统,对草甸草原没有显著影响。在不同草地生态系统中,随着放牧强度的增加,土壤呼吸速率呈先升高后降低的变化规律。方差结果显示,不同草原类型的土壤10 cm温度和空气相对湿度有极显著性的差异(P<0.001),不同放牧强度对土壤10 cm温度和空气相对湿度无显著性影响。 相似文献
3.
桑树不同品种生态特性的研究 总被引：4，自引：3，他引：1
为依据生态学的原理和规律建设高产优质桑园,研究了湖桑32号、农桑12号、新一之濑、选792号等不同品种桑园的土壤温度、土壤含水量、土壤呼吸强度、CO_2浓度、空气温度、空气相对湿度、光合有效辐射等生态特性。4个品种的土壤呼吸速率依次为农桑12号>湖桑32号>新一之濑>选792号;增加空气相对湿度的大小顺序为农桑12号>选＊蛇号>湖桑32号>新一之尬湖桑32号周围的地浓度显著高于其它3个品种;农桑12号降低气温的生态特性较为显著。对不同品种桑园与空旷地气候因素进行差异性分析认为,夏季桑园具有降低气温、增加空气相对湿度、降低土壤温度、减少土壤蒸发、增加土壤含水量的生态作用。 相似文献
4.
Energy metabolism of groups of broiler breeders in open-circuit respiration chambers 总被引：1，自引：0，他引：1
Energy metabolism of broiler breeders housed in groups was measured in large open-circuit respiration chambers. The design, function and calibration of the chambers are described. Each of the three chambers has a capacity for 24 pullets or adult layers, or 16 adult broiler breeders. Control of ventilation rate is by calibrated choked-flow nozzles. Before experiments were started the system was assessed by CO2 infusion and recovery and ethanol combustion studies. Percentage CO2 recoveries were greater than 98 of infused and the mean (+/- SD) quotient of CO2 produced to O2 consumed from the combusion of ethanol was 0.67 (+/- 0.02). Forty-eight broiler breeder hens in lay were placed in the respiration chambers (16 per chamber) and fed at different rates from around maintenance to about twice this value. The energy required for maintenance (MEm) was 365 kJ/kgW0.75 d and the efficiency of utilisation of metabolisable energy (ME) for production (kp) was 0.70. Starvation heat production was about 350 kJ/kgW0.75 d and was shown to affect the derived values of the energetic parameters when included in the relationship between retained energy and metabolisable energy intake. Published results were recalculated and found to support this. 相似文献
5.
An open-circuit indirect respiration calorimetry system for the collection of long-term metabolic heat production data for medium and small animals is described. The system is designed for use with small ruminants, but it has the capacity for measuring heat production in nonruminant species up to 150 kg. The system consists of an internal climatic control system, air flow control and volume measuring system, and gas analyzers for O2, CO2 and CH4. Carbon dioxide recovery checks of the four chambers produced recovery values ranging from 96.73 to 100.89%. The actual mean fasting heat production measured for 12 wether sheep was 63.13 kcal/kg.75 +/- .83. The total estimated cost of four chambers and the associated instrumentation was less than $17,000 in 1984. 相似文献
6.
本试验研究了不同相对湿度(RH)对日增温环境中肉仔鸡生理指标的影响。试验选取22日龄爱拔益加(AA)肉仔公鸡180只转入人工气候试验舱,随机分成3个组,每组6个重复,每个重复10只鸡。适应期7 d,温度20℃,RH为60%。肉鸡29日龄时,试验RH分别调整到35%、60%和85%,至试验结束。环控舱内温度每天升高2℃,试验期共9 d。肉鸡37日龄时,环控舱舱内温度升高至38℃,试验期间肉鸡自由采食饮水,试验全程不抓鸡,选择非接触性生理指标进行测定,以尽量避免肉鸡产生应激。结果表明:肉鸡体核温度(CT)、耳叶温度(ET)、小腿温度(LT)、呼吸频率(RR)、采食量(FI)和饮水量(DW)均存在拐点温度(IPt)。首先变化的是LT,其产生变化的环境温度范围是24.6~25.1℃,之后是ET和CT,发生变化的环境温度范围分别是25.0~25.1℃和25.5~26.4℃。RR存在2个IPt(IPt1和IPt2),温度范围分别是25.5~27.2℃和32.5~33.3℃。环境温度大于IPt1值时,RR随温度升高而升高;环境温度大于IPt2值,RR随温度升高而下降。FI、DW发生变化的环境温度范围分别为27.1~29.3℃和29.2~29.5℃,环境温度大于IPt值后,FI和DW随温度升高而降低。高湿组FI的IPt值显著高于低湿组和中湿组(P0.05),高湿组死亡率(MR)的IPt2值显著小于低湿组和中湿组(P0.05),高湿组CT、ET、LT、RR、FI和DW的IPt值小于中湿组和低湿组,RH对ET、LT、RR和DW模型参数均无显著影响(P0.05)。结果提示:环境温度对肉仔鸡生理指标影响较大,RH影响较小。FI下降和CT升高的IPt值可被认为是上限临界温度,4~5周龄肉仔公鸡CT上限临界温度为25.5~26.4℃;RR开始升高和FI开始下降的上限临界温度分别为25.5~27.2℃和27.1~29.2℃;死亡的上限临界温度在为32.7~33.5℃。肉仔鸡死亡时CT高出常数值4.6~5.1℃。4~5周龄肉仔公鸡不同生理指标有着不同的上限临界温度。 相似文献
7.
The purposes of this study were to determine whether the storage mite, Tyrophagus putrescentiae , could survive and thrive on dog food and if mould growth was important to their survival. All of the chambers ( n = 42) were started with 10 female mites and evaluated every other day for mite survival and for the spontaneous development of mould. Ten chambers tested the effect of low moisture on mite survival. Eight chambers were used as positive and negative controls ( n = 4 each); positive control mites were fed Fleischmann's® yeast and negative controls had no food source. Three dog foods were evaluated in the same manner. Four chambers had food but mould development was limited by replacing the food kernel every 48 h and four chambers were allowed to grow mould. Mites grown in chambers without moisture died from desiccation within 5 days. The termination point was day 34 when all mites in the negative control group (moisture but no food) died. Although T. putrescentiae survived and grew on all three commercial dog foods, there was no statistically significant difference in mites counts among the dog foods ( P < 0.10). Mite counts in the 'no' mould and mould groups ranged from 8 to 11 and 144 to 245, respectively, and differences were significant ( P < 0.0001). This study found that T. putrescentiae is a fungivorous storage mite that can grow and flourish on dog food. The study demonstrated that the presence of mould positively influences mite viability, while low relative humidity can result in detrimental consequences for T. putrescentiae. 相似文献
8.
为明晰高寒湿地生态系统碳水耦合机制，本研究基于2004—2009连续6年青海海北高寒湿地生态系统通量数据计算出总初级生产力和蒸散量变化，进而计算出高寒湿地水分利用效率变化。结果表明：年际尺度上，湿地生态系统呼吸速率、水分利用效率和生态系统CO2净交换量均呈极显著上升趋势；季节尺度上，连续6年间非生长季生态系统碳排放总量大于生长季碳吸收总量；针对生态系统呼吸速率和水分利用效率均呈现出生长季值大于非生长季值；结构方程模型结果揭示相对湿度极显著影响高寒草甸湿地生态系统CO2净交换量、生态系统呼吸速率和水分利用效率变化；水分利用效率和生态系统CO2净交换量分别受净辐射和降水量的极显著影响。该研究结果可为高寒生态系统碳水耦合及对气象因子变化适应等提供理论依据。 相似文献
9.
黄土高原紫花苜蓿草地土壤呼吸对刈割的响应 总被引：2，自引：1，他引：1
摘要：使用动态密闭气室红外CO2分析法（IRGA）测定黄土高原地区不同刈割时间处理的紫花苜蓿（Medicago sativa）草地土壤呼吸速率日动态,分析土壤呼吸与土壤温度、大气温度和大气湿度间的关系。结果表明,CO2日排放量表现为未刈割极显著大于5月27日刈割处理（P<0.01）,不同刈割时间处理间差异不显著（P＞0.05）,说明合理刈割减少了CO2排放量。土壤呼吸速率全天最低值均出现在06:00日出前,但最大值在不同刈割时间处理中不一致。土壤呼吸和5 cm土壤温度呈指数关系,与大气温度呈一元二次函数关系,与大气相对湿度呈负线性相关关系。 相似文献
10.
新型自控大型开闭式呼吸测热室经自行设计研制已获成功。每个室的容积约18200立升.室壁由1—1.6cm厚的塑料板深度焊接而成一整体,并有10cm厚的绝热层,采用充气门封技术,气密性好,容易加工和维修,造价低廉。用容积补偿装置保持内外气压相等。呼吸室的机械系统,运转,气体采样及分析,数据处理、运算及结果的打印均由1台微机自动控制。全部采用国产材料和仪器。经燃烧模拟呼吸试验表明CO_2和O_2的R~2均达到0.999。经香猪的绝食代谢和阉牛维持饲养水平代谢产热试验表明测定性能很稳定。 相似文献
11.
12.
植物根系呼吸研究方法及影响因素研究进展 总被引：3，自引：0，他引：3
植物根系呼吸是土壤呼吸的主要组成部分,与陆地生态系统碳循环和气候变化密切相关。根呼吸的研究对生态系统碳收支及生物圈碳平衡有重要意义。植物根呼吸受环境及生物等多种因素影响,根呼吸速率及其对土壤总呼吸的贡献在不同生态系统有较大的差异性。根呼吸的测定主要通过离体根法、同位素法及PVC管气室法等直接方法和排根法、计算法等间接方法进行测定或估算。植物根呼吸主要受土壤温度、湿度、养分及根直径、根级、根生物量及菌根等因素影响。本文从根呼吸主要研究方法和影响根呼吸因素两方面对已有的研究进行简要的综述,旨在为植物根呼吸研究提供理论依据,并根据目前的研究现状,对相关内容进行展望。 相似文献
13.
Effects of elevated ambient temperature on puberty and related physiological responses were studied in 40 gilts. Group 1 (n = 20) gilts were born in September and Group 2 (n = 20) gilts were born in March. Gilts were placed in environmentally controlled chambers at 140 d of age. After a 10-d acclimation period at 20 degrees C, 35% relative humidity (RH), and 12 h light (L)/12 h dark (D), gilts within each group were randomly assigned to one of two treatments: control (C; 15.6 degrees C, 35% RH, 12 h L/12 h D) or heat stress (HS; 33.3 degrees C, 35% RH, 12 h L/12 h D). Daily detection of estrus with a boar began at 180 d of age and continued for 50 d. All gilts not reaching puberty by 230 d of age received 1,000 IU pregnant mare serum gonadotropin (PMSG) and 7 d later were examined by laparotomy. Rectal temperatures (REC) and respiration rates (RESP) were taken twice daily. Food intake (FI) and water usage (WC) were recorded daily. Blood samples were collected weekly and BW recorded at 150, 190, and 230 d of age. No differences (P greater than .05) were observed due to season of birth. Heat-stressed gilts had greater (P less than .001) REC and RESP and consumed more (P less than .01) water than C gilts. Food intake and ADG were not different between treatments (P greater than .05).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
14.
J. BUYSE H. MICHELS J. VLOEBERGHS P. SAEVELS J.M. AERTS B. DUCRO 《British poultry science》1998,39(2):264-272
1. A new open-circuit respiration unit consisting of 6 respiration chambers, gas analysis unit and data-acquisition system is briefly described. 2. Energy and protein metabolism in broiler lines selected for improved food efficiency (FC) or for growth rate (GL) were measured weekly from 3 to 6 weeks of age. 3. Gross and apparent metabolisable energy intake per kg W 0.75 was on average higher for GL than for FC chickens without differences in metabolisability. Fed and fasted heat production per kg W 0.75 did not differ between the lines. FC chickens retained less energy per kg W 0.75 than GL chickens. 4. FC chickens deposited much less of the retained energy as fat than their GL counterparts and also showed greater protein conversion efficiency. The leaner composition of the body weight gain in FC chickens was confirmed by the estimated lower fat deposition per kg W 0.75 and by the lower fat protein ratio. 相似文献
15.
准噶尔盆地荒漠灌丛草地土壤呼吸变化及其对土壤温、湿度的响应 总被引：1，自引：0，他引：1
本研究利用Li-8100开路式土壤通量测量系统对新疆准噶尔盆地古尔班通古特沙漠南缘荒漠灌丛草地生长季土壤呼吸速率进行了观测,分析了该地土壤呼吸特征及其与土壤温、湿度的关系。研究表明各层土壤温、湿度随着季节表现出明显的周期性变化特征,不同深度土壤温、湿度垂直梯度明显。荒漠灌丛草地土壤呼吸白天呈"双峰型"曲线;生长季土壤呼吸速率白天高于夜晚,草地土壤呼吸速率约为裸地的4倍;裸地夜间土壤表现为碳吸收过程。白天土壤呼吸速率与土壤温、湿度呈负相关关系,夜间为正相关关系;生长季白天土壤水分条件对土壤呼吸速率的影响更大,而夜间土壤温、湿度对土壤呼吸过程的影响均小于白天。该研究为明确干旱区碳收支过程提供一定的理论依据。 相似文献
16.
为了解广西鸡舍内主要环境因子变化对蛋鸡生产性能的影响,本试验以全封闭笼养蛋鸡舍为对象,于2018年04月-2018年5月,每天监测鸡舍内环境的温度、相对湿度、CO2、NH3、H2S、SO2浓度变化,测定点设在鸡舍的前中后位置,每隔3 d测定鸡舍内细菌的总数,并分析各种环境因子与蛋鸡生产性能的相关性。结果显示,4月份和5月份蛋鸡舍内的温度与相对湿度均呈正相关关系,与CO2和NH3浓度均呈负相关关系(P<0.01),温度在29.1℃~30.2℃时,温度与产蛋率呈显著负相关(P<0.05);日均相对湿度与日均CO2浓度均呈负相关关系(P<0.01),5月份日均相对湿度与舍内日均NH3浓度呈负相关关系(P<0.05);4月份和5月份舍内日均CO2浓度与NH3浓度呈正相关关系;舍内温度、相对湿度、CO2浓度和NH3浓度与鸡舍内环境空气细菌总量有一定相关性;鸡舍内环境空气细菌总量与日均蛋鸡淘汰率、日均破蛋率相关关系不明显。试验表明,全封闭鸡舍内温度的升高对本地蛋鸡的产蛋率有显著影响,应及时调整通风和降温措施,以免影响蛋鸡的产蛋率。 相似文献
17.
环境温度和湿度对蛋鸡粪便含水率、氮素和pH的影响 总被引：1，自引：0，他引：1
为了研究温度、湿度因子对存放期蛋鸡粪便含水率和氮素变化的影响,试验在人工气候箱内采用单因素试验设计,分别研究存放0~6d在15、20、25、30℃的温度水平和65%、75%、85%、95%的湿度水平下蛋鸡粪便的成分特性变化。结果表明,在不同环境温度下,0~6d内随着时间延长,蛋鸡粪便含水率均下降;最初1~2d内含水率变化较小,从第3天开始,高温环境(35℃)贮放粪便不利于含水率的降低。环境温度越高,12h~4d粪便pH值上升越快;高温(35℃)会加快粪便降解和氮素损失,而在25℃环境下,环境湿度对存放期粪便的含水率、pH值以及氮素变化没有显著影响。 相似文献
18.
对猪巴氏杆菌病的发生与气候因素(温度、相对湿度、降雨量、日照时数)的相关性进行了分析研究.结果表明,该病的发生与气候因素有一定的相关性.与温度、相对湿度、日照时数呈正相关,相关系数分别为0.249 4,0.361 9和0.039 6;与降雨量呈负相关,相关系数为-0.2 366,但差异均不显著,说明在防治疾病时,应考虑这些气候因素,但不是主要因素. 相似文献
19.
研究认为 :蚕茧干燥中室内相对湿度峰值不出现在临排气前的 82℃时段 ,而是位于鲜茧进灶 10min左右的 70℃附近 ;在现行干燥设备及控湿条件下 ,等速干燥阶段空气相对湿度基本符合干燥工艺要求 ,但减速干燥阶段则相差较大 ,应进行人工补湿。对茧层含水率的测定分析认为 ,预热段加温速度会对茧层含水率产生影响 ,快速加温有利于缩短杀蛹时间 ,维持较适当的茧层含水率。但生产上以中速偏快加温方式 (加温速度 1 0～ 1.2℃ /min)为宜。茧层含水率高低与灶内空气相对湿度的大小有密切联系 ,二者相关系数达 0 8312 ,且相对湿度 2 0 %及以上时与 10 %及以下时的茧层含水率间差异达显著水平 相似文献
20.
The effect of supplementary administration of recombinant bovine somatotrophin (rbST) on the renal tubular handling of sodium in crossbred 87.5% Holstein cattle housed in normal shade (NS) or mist-fan cooled (MF) barns was evaluated. The cows were injected with 500 mg rbST at three different stages of lactation. The MF barn housed cows showed a slightly decreased ambient temperature and temperature humidity index, but an increased relative humidity. Rectal temperature and respiration rates were significantly lower in cooled cows. The rbST treated cows, housed in NS or MF barns, showed markedly increased milk yields, total body water, extracellular fluid and plasma volume levels, along with a reduced rate of urine flow and urinary excretion of sodium, potassium and chloride ions and osmolar clearance, in all three stages of lactation. Renal tubular sodium and water reabsorption were increased after rbST administration without any alteration in the renal hemodynamics. Lithium clearance data suggested that the site of response is in the proximal nephron segment, which may be mediated via increases in the plasma levels of aldosterone and IGF-1, but not vasopressin, during rbST administration. 相似文献