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101.
102.
《The Journal of Applied Poultry Research》2006,15(2):333-340
Reduction of airborne dust in enclosed animal housing has been shown to result in corresponding reductions in airborne bacteria, ammonia, and odor. The search for strategies to reduce particulate matter and ammonia emissions from animal housing has led to considerable interest in the poultry industry for practical systems to reduce these air emissions. Technologies that have been shown to be effective for reducing airborne dust in animal areas include misting with an oil spray, water mists, extra ventilation, and electrostatic space charge systems. An electrostatic space charge system (ESCS) was designed to reduce airborne dust and ammonia emissions from a commercial broiler production house. The ESCS for this application was based on patented technology developed to reduce airborne dust and pathogens. Two commercial broiler houses with built-up litter (a control house and one outfitted with an ESCS unit) were monitored for dust and ammonia concentrations over a period of 7 flocks. Results of this study indicate the ESCS significantly reduced airborne dust by an average of 43% and reduced ammonia by an average of 13%. Power consumption of the ESCS system was less than 100 W when in operation. Commercial application of this technology within the production house has the potential to improve in-house air quality and reduce particulate emissions. 相似文献
103.
慢性氨气暴露对肉鸡NK细胞杀伤活性和血清新城疫抗体效价和溶菌酶的影响 总被引:1,自引:0,他引:1
为探讨氨气对肉鸡免疫功能的影响,选择240只1日龄AA肉公鸡,随机分成4个处理组,分别饲养在4个独立的、环境可控制的实验舱内。4个环控仓氨气浓度设计为0~3周龄分别为0、13、26mg/kg和52mg/kg;3~6周龄分别为0、20、40mg/kg和80mg/kg。结果表明:高浓度氨气暴露3周和6周,肉鸡血清溶菌酶均表现降低,其中3周龄溶菌酶降低较显著(P<0.05);肉鸡氨气暴露6周后,NK细胞杀伤活性显著下降(P<0.05),新城疫弱毒疫苗免疫效能显著降低(P<0.05)。这一结果表明肉鸡暴露在高浓度氨气环境中,其免疫功能会表现降低。 相似文献
104.
持续、低剂量金霉素对肉仔鸡肠道微生物、血氨、尿酸和生产性能的影响 总被引:14,自引:2,他引:12
360只商品代Abor Acre肉用公鸡随机分为2组,每组4个重复,对照组金霉素的添加量为0mg/kg,处理组金霉素的添加量为150mg/kg,研究金霉素对肉仔鸡肠道微生物、血氨、尿酸和生产性能的影响。每隔7d检测肉仔鸡直肠和空肠中大肠杆菌、乳酸菌和双歧杆菌的变化情况,每隔2检测血液中氨和尿酸含量,每隔2周记录肉仔鸡体重和饲料消耗。试验结果表明,150mg/kg的金霉素对肉仔鸡的生长显著的促进作用,在3以前促进生长作用极显著(P<0.01),3周之后作用显著(P<0.05);在33日龄前,对直肠中的大肠杆菌具有显著的抑制作用(P<0.05),之后抑制作用消失(P>0.05),对空肠中大肠杆菌的抑制作用在19日龄前显著(P<0.05),之后作用消失(P>0.05);在12日龄前,对直肠和空肠中乳酸菌具有明显抑制作用(P<0.05),之后作用消失(P>0.05);对直肠和空肠中双歧杆菌均无显著影响(P>0.05);极显著降低35日龄以前肉仔鸡血氨浓度(P<0.05),之后作用效果降低,但仍显著(P<0.05);在21日龄前,显著降低血液尿酸含量(<0.05),49日龄时作用效果不显著(P>0.05)。研究表明,金霉素以低剂量、持续在饲料中添加时,对肉仔鸡的生长和采食具有显著的促进作用,这种促进作用与其抑制肠道中大肠杆菌、延缓肠道微生物的定植过程,以及降低血氨浓度有关。金霉素对肠道微生物的影响因菌种不同而有明显差异,而且对大肠杆菌不产生永久性抑制。血液尿酸含量的降低说明金霉素具有促进肉仔鸡氮沉积的作用。 相似文献
105.
K Jensen 《Acta veterinaria Scandinavica》1975,16(2):258-268
The effect of feeding level and interval between feedings on the fermentation pattern in the bovine rumen have been investigated in experiments with hay. The animals were completely adapted heifers fitted with rumen cannulas, and the parameters measured were ammonia, pH, volatile fatty acids (VFA) and non-glucogenic/glucogenic ratio (NGGR) in the VFA mixture.Increasing feeding levels, ranging from 2/3 to 4/3 of maintenance level, resulted in higher average concentrations of VFA and lower pH in the rumen fluid. Further the highest level of intake caused a considerable diurnal variation in the pH and the concentration of total VFA, and increased the variation in the molar composition of the VFA mixture.Three feeding intervals ranging from 8 to 16 hrs., with hay administered at maintenance level, caused no changes in the fermentation pattern.Typical variations in the concentrations of ammonia and valeric acid as related to time after feeding were demonstrated, but the concentrations of the branched-chain fatty acids in the rumen fluid were found to be quite constant.It may be concluded that a representative mean value of the parameters measured, except for ammonia and valeric acid, may be based on relatively few samples when feed intake does not exceed maintenance level, whereas sampling every hour is required at higher feeding levels. 相似文献
106.
无水氨、尿素氨化秸秆饲喂肉牛的效果 总被引:2,自引:0,他引:2
为了评价无水氨、尿素氨化麦秸、玉米秸饲喂肉牛的效果,用42头肉用生长母牛及阉牛进行了80天饲养试验。试验开始牛平均体重为135公斤,按随机区组设计分为7组,占干物质3%的无水氨氨化麦秸组(WA)、占干物质5.4%的尿素加大豆粉氨化麦秸组(WUS)、麦秸组(W);占干物质3%的无水氨氨化玉米秸组(CA)、占干物质5.4%的尿素加大豆粉氨化玉米秸组(CUS)、占干物质5.4%的尿素氨化玉米秸组(CU)、玉米秸组(C).各组牛秸秆自由采食,混合精料按体重的1%喂给。为了平衡日粮粗蛋白质水平,W组及C组每日每头分别加喂32克和37克尿素。试验结果表明:秸秆经氨化处理后含氮量提高88-151%,肉牛采食每公斤秸秆干物质的时间显著缩短。WA组、WUS组、W组、CA组CUS组、CU组和C组的日增重分别为0.66、0.54、0.52、0.57、0.63、0.56、0.48公斤(P<0.01)。添加大豆脲酶对尿素氨化玉米秸的效果无明显影响。 相似文献
107.
Lori S. Waddell DVM DACVECC David E. Holt BVSC DACVS Dez Hughes BVSc MRCVS DACVECC Urs Giger PD DR. med. vet. DACVIM 《Journal of Veterinary Emergency and Critical Care》2001,11(1):23-26
Objective: To determine the effect of storage on ammonia concentration in canine packed red blood cell (pRBC) units.
Design: In vitro and in vivo study.
Setting: University Veterinary Teaching Hospital.
Interventions: Ammonia concentration was measured in 7 units of canine pRBC prepared in citrate-phosphate-dextrose (CPD) and Adsola on Days 1 and 35 of storage. Ammonia was measured in 4 additional units of canine pRBC on Days 0, 7, 14, 21, 28, and 35. Plasma ammonia was also determined in 5 anemic dogs receiving pRBC.
Measurements and Main Results: Ammonia concentration increased from 73 ± 15 mmol/L (mean ± SD) on Day 1 to 800 ± 275 mmpl/L on Day (p<0.001). When measured every 7 days in 4 units of canine pRBC, ammonia concentration increased from 23 ± 8 mmol/L on Day 0 to 179 ± 13 mmol/L (Day 7), 276 ± 56 mmol/L (Day 14). 383 ± 47 mmol/L (Day21), 466 ± 30 mmol/L (Day 28), and 562 ± 27 mmol/L (Day 35) (p<0.05 for all comparisons). In a preliminary study, plasma ammonia concentration measured in blood samples from 5 anemic dogs without primary liver disease immediately before and after transfusion with 5–10 ml/kg of stored pRBC remained in the normal reference range.
Conclusions: The ammonia concentration in stored canine pRBC increased markedly with time. In this preliminary study, ammonia concentrations in dogs without primary liver disease did not increase above the reference range after transfusion with pRBC. 相似文献
Design: In vitro and in vivo study.
Setting: University Veterinary Teaching Hospital.
Interventions: Ammonia concentration was measured in 7 units of canine pRBC prepared in citrate-phosphate-dextrose (CPD) and Adsol
Measurements and Main Results: Ammonia concentration increased from 73 ± 15 mmol/L (mean ± SD) on Day 1 to 800 ± 275 mmpl/L on Day (p<0.001). When measured every 7 days in 4 units of canine pRBC, ammonia concentration increased from 23 ± 8 mmol/L on Day 0 to 179 ± 13 mmol/L (Day 7), 276 ± 56 mmol/L (Day 14). 383 ± 47 mmol/L (Day21), 466 ± 30 mmol/L (Day 28), and 562 ± 27 mmol/L (Day 35) (p<0.05 for all comparisons). In a preliminary study, plasma ammonia concentration measured in blood samples from 5 anemic dogs without primary liver disease immediately before and after transfusion with 5–10 ml/kg of stored pRBC remained in the normal reference range.
Conclusions: The ammonia concentration in stored canine pRBC increased markedly with time. In this preliminary study, ammonia concentrations in dogs without primary liver disease did not increase above the reference range after transfusion with pRBC. 相似文献
108.
S. V. Chanda A. K. Joshi P. P. Vaishnav Y. D. Singh 《Journal of Agronomy and Crop Science》1988,160(2):125-131
Changes in the activities of enzymes of ammonia assimilation viz., glutamate dehydrogenase (GDH), glutamine synthetase (GS) and glutamate synthase (GOGAT), together with the activities of glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) were analysed in the topmost fully expanded leaf of pearl millet (Pennisetum americanum L. Leeke) hybrid BJ-104 , and its parents, J-104 and 5141-A , during the entire period of growth in field. Ammonia assimilation enzymes showed strong ontogenic trends and the hybrid attained activities either equal to the better (male) parent or showed better parental heterosis. In contrast to this both GOT and GPT activities were slightly higher than the poor (female) parent. The role of these enzymes in relation to chlorophyll synthesis and transport of metabolites from cellular compartments of C4 plants, are discussed. Surveying the literature on attempts to propose biochemical criteria for hybrid vigour, it is proposed that there cannot be a universal criterion, rather rate limiting steps in different cultivars should be searched. 相似文献
109.
中国制造业碳排放的演变特征与影响因素分析 总被引:2,自引:0,他引:2
运用LMDI分解模型,对1995年~2007年我国制造业碳排放变动特征及其影响因素进行研究,结果表明:我国制造业碳排放在考察期内呈"U"型变动趋势,且存在较大的行业差异,能源密集型行业碳排放总量较大,能源效率、能耗总量与结构上的行业差异是造成这一状况的根源;其次,经济总量是促进碳排放逐年增长的主要因素,且呈逐年增长的发展趋势,其年均贡献达到48.51%;产业结构调整、能源技术进步与能源结构优化是减缓碳排放的主要因素,其中以能源技术进步的减排效果最为显著;制造业减排的关键在于重点耗能部门的结构调整和技术进步,与煤炭等高碳能源的高效、清洁利用。 相似文献
110.
氨氮对凡纳滨对虾稚虾的急性毒性作用 总被引:1,自引:0,他引:1
实验研究了氨氮对体长3.2cm、体质量0.356g(n=10)与体长1.6cm、体质量0.036g(n=15)两种规格凡纳滨对虾(Litopenaeus vannamei)稚虾的急性毒性效应。血氨和碱性磷酸酶活性的测定结果显示,血氨随氨氮浓度的升高而升高,碱性磷酸酶(AKP)活性随氨氮的升高而下降。急性毒性实验结果表明,体长3.2cm稚虾的游离态氨24hLG。为2.068mg/L、48hLC5。为1.654mg/L、96hLG。为1.395mg/L,生存安全浓度sc为0.3969mg/L;体长1.6em稚虾的游离态氨24hLGo为1.577mg/L、48hLG0为1.042mg/L、96hL氏为1.012mg/L,生存安全浓度Sc为0.2065mg/L。 相似文献