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71.
试验目的在于研究枯草芽孢杆菌(Bacillus subtilis)Z-27制剂对断奶仔猪肠道消化酶活力、常规营养成分、生长性能的影响,为该菌剂的益生机理的研究提供参考。将供试仔猪分为试验组和对照组,试验组饲喂添加0.1%Z-27菌剂的T2饲料,对照组饲喂T2饲料。采用GB/T 23527—2009、GB/T8275—2009等方法测定仔猪粪便中蛋白酶、α-淀粉酶等消化酶活力;利用GB/T 6435—2006、GB/T6432—94等方法测定粪便中水分、粗蛋白质等常规养分的含量;记录采食量并称取始重和末重。试验表明,与对照组相比,试验组仔猪的粪便中蛋白酶、α-淀粉酶、纤维素酶的平均活力和脂肪酶水解液酸价分别提高了62.99%、34.56%、133.10%和66.57%;粪便中残留的粗蛋白质、淀粉、粗脂肪和粗纤维等有机成分含量分别下降了30.51%、52.13%、18.44%和26.73%,而无机成分的含量基本无变化;平均日增重提高了9.38%,料重比降低了4.94%。研究表明,枯草芽孢杆菌Z-27制剂具有提高仔猪肠道消化酶活力、提高饲料转化率、改善仔猪生长性能的作用。 相似文献
72.
三峡库区传统耕作措施水土保持机理研究 总被引:3,自引:1,他引:2
通过大量野外勘查、测量数据,说明了传统耕作措施的规律性及其坡长与坡度特征参数,同时将物理过程侵蚀模型(WEPP)模拟结果与实测数据进行对比分析,主要从坡长因子的角度阐明了传统耕作措施的水土保持作用机理。研究结果表明,实测的5°~10°、10°~15°、15°~20°、20°~25°、25°~30°坡面对应的坡长分别为7~10 m、5~7 m、4~6m、3~5 m、3~4 m,与同一坡度条件下WEPP模拟的坡面侵蚀发生的突增拐点值比较接近;传统耕作措施通过缩短坡长来分散坡面径流,阻止细股流的形成,从而有效防止了坡耕地中主要的侵蚀类型——细沟侵蚀。 相似文献
73.
B. W. BEAVERS Z. LIU M. S. COX W. L. KINGERY G. E. BRINK P. D. GERARD K. C. MCGREGOR 《土壤圈》2010,20(2):217-288
An experiment arranged in a randomized complete block design with three replications was conducted on a Lexington soil (fine-silty, mixed, active, thermic, Ultic Hapludalfs) and a Loring soil (fine-silty, mixed, active, thermic, Oxyaquic Fragiudalfs) in Mississippi from September 1997 to September 2000 on 18 runoff plots under natural rainfall condition to study the phosphorus (P) dynamics in poultry litter amended soils under three management systems combining tillage and planting date treatments to identify effective management practices in southern U. S. A. The management systems in the study were:1) tillage in the fall prior to litter application followed by a delayed planting of fall forages (CT-DP); 2) tillage followed by immediate planting of the fall forage with subsequent litter application (CT-IP); and 3) no-till with planting prior to litter application (NT-IP). The results indicated that there was significant increase in soil P after 3 years of poultry litter application for both Lexington and Loring soils (P <0.05). Based on P budget analysis, the majority of P from poultry litter application (> 90%), was accumulated in both soils. In Loring soil, soluble P mass in the runoff was significantly higher from NT-IP than from CT-DP and CT-IP over the entire study period (P <0.01). For both soils, there were no significant differences in sediment P mass between management systems. For Loring soil, CT-DP and CT-IP were effective management practices to mitigate negative effects due to poultry litter application. 相似文献
74.
75.
秦汉时期,官方蓄犬非常普遍。按正史记载及律令要求,此种现象既是选择偏好,也是制度使然,从朝廷中央到地方郡县、边关烽燧莫不如此。与之相应的是官方也为之配备专门的馆舍和官员。对这些犬只的管理,秦汉律令从数量、饲养环境、体型大小等角度都有限制。它们满足了各级官府治理鼠患、祭祀驱邪、娱乐狩猎、警戒防盗、肉食供给等多方面的需要。另外,此时文武官员对皇帝常以"犬马"自称,这种现象或许也与官方蓄犬浸染有关。 相似文献
76.
77.
Zhongqi HE Irenus A. TAZISONG Xinhua YIN Dexter B. WATTS Zachary N. SENWO Henry Allen TORBERT 《土壤圈》2019,29(2):180-194
Sustainable agricultural practices have been steadily increasing in the last couple of decades. These management practices frequently involve cover crops, less or no-tillage, and organic fertilization. In this study, we evaluated the effects of cropping systems,tillage and no-tillage, and the application of poultry litter(PL) on selected soil physicochemical properties and soil test nutrients. Soil samples were collected from the topmost surface(0–5 cm) and subsurface(5–10 cm) layers. The general effect trend was PL application no-tillage cover crop cropping type. There were more statistically significant(P ≤ 0.05) correlations between the 18 soil attributes at the topmost surface than at the subsurface. This could be due to the accumulation of external C inputs and nutrients by crop residues and PL application as well as the retaining effects of no-tillage on less mobile nutrient components. Because of their high mobility and volatile nature, total nitrogen(N), ammonia-N(NH_4~+-N), and nitrate-N(NO_3~--N) levels varied greatly(high standard deviations), showing no consistent patterns among the treatments. Compared to the soybean cropping system, corn, especially with the wheat cover crop, contributed more to the total carbon(C) and sulfur(S) in the topmost surface soils(0–5 cm). Poultry litter application greatly increased pH, cation exchange capacity(CEC), base saturation, magnesium(Mg), phosphorus(P), calcium(Ca),sodium(Na), potassium(K), manganese(Mn), copper(Cu), and zinc(Zn) in both soil layers. Contrast comparisons revealed that PL application had more of an effect on these soil chemical properties than no-tillage and cropping systems. These results will shed light on developing better nutrient management practices while reducing their runoff potentials. 相似文献
78.
微生物素在果蔬采后保鲜中有重要的应用价值,但目前实际应用在果蔬采后保鲜领域中的并不多。本文分析了目前已经应用到果蔬保鲜领域的微生物素种类,有乳酸链球菌肽、溶菌酶、木霉发酵液等,分析了其抑菌保鲜原理及研究现状;并结合微生物素的特点,提出了微生物素在未来果蔬采后保鲜中的发展趋势,即面对冷藏技术使用不完善的现象,可以开发利用更多的微生物素种类,如纳他霉素、红曲霉素、短梗霉多糖等,为今后果蔬采后保鲜领域的健康可持续发展提供参考。 相似文献
79.
利用BIOLOG系统对不同种类细菌鉴定的研究 总被引:3,自引:1,他引:2
为完善细菌鉴定工作,本试验通过利用BIOLOG细菌自动微生物分析系统(简称BIOLOG系统)对13株大肠杆菌、15株巴氏杆菌和7株金黄色葡萄球菌进行了鉴定,并与传统方法[1]包括形态学观察、革兰氏染色、生化实验等的鉴定结果进行了比对.实验结果表明,与传统方法相比BIOLOG系统具有准确、快捷、简便的优点,同时也有一定的局限性,从而为BIOLOG系统的更好使用提供了实验依据. 相似文献
80.
A study was conducted to estimate the record keeping, genetic selection, educational, and farm management effects on average
milk yield per cow (AYC), milk fat percentage, bacterial score, and bulk tank somatic cell count (BTSCC) of dairy farms in
the central region of Thailand. Farms were located in the provinces of Saraburi and Nakhon Ratchisima and were members of
the Muaklek dairy cooperative. Records from individual animals were unavailable. Thus, farm records of milk yield, milk fat
percentage, bacterial score, and BTCCC were collected from July 1, 2003 through June 30, 2006. Additional record keeping,
genetic selection, education, and farm management information was collected through a questionnaire in May of 2006. Data from
the Muaklek dairy cooperative and the questionnaire were then merged by a farm identification number. A single trait mixed
model was used to analyze AYC, milk fat percentage, and BTSCC, while a log linear model was used to analyze bacterial score.
Results showed that farms that kept records on individual animals had higher (P < 0.05) milk fat percentages and lower bacterial scores than farms that did not. Farms that used genetic information (EBV)
and phenotypes when selecting sires were higher (P < 0.05) for milk fat percentage than farms that used only phenotypes and personal opinion. Farms milking cows with a single
unit milking machine and by hand, had higher (P < 0.05) bacterial scores and BTSCC than farms using only a single or multi unit machine. Overall farms that kept individual
animal records, used EBV when selecting sires, used a single method for collecting milk, and used family labor achieved higher
performance from their herds than farms that did not. 相似文献