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91.
92.
额济纳胡杨林土壤含水量时空变化的研究   总被引:10,自引:0,他引:10  
使用管状土壤水分仪,对额济纳胡杨林、沙枣林、柽柳林以及其它不同样地的土壤含水量时空变化进行了调查研究。结果表明,大部分样地有大约20CM的干沙层,使表层土壤含水量最低;土壤剖面的30~150CM土层内,随土壤深度的增加,土壤含水量逐渐增大;沙枣林和柽柳林的土壤含水量明显高于胡杨林土壤含水量;土壤质地的变化和三种林型耗水量的差异是土壤含水量高低变化的原因;2004年5月份的土壤含水量明显高于2003年7月份的土壤含水量。  相似文献   
93.
米易县核桃产业发展的思考   总被引:1,自引:0,他引:1  
在论述了米易县核桃产业发展现状的基础上,分析了米易县发展核桃产业的必要性和存在的问题,针时存在问题提出了相应的对策和建议:一是以核桃基地建设为重点,合理规划核桃种植;二是以科技为依托,强化技术支撑体系;三是引进龙头企业,带动核桃产、工、销一体化发展;四是拓宽核桃产业发展的融资渠道;五是建立苗圃基地,确保良种供应;六是制定一系列的优惠政策,促进核桃产业健康快速发展。  相似文献   
94.
Abstract— A12-wk feeding experiment was conducted to study the feasibility of utilizing cluster bean seed meal (CBM) as a replacement for fishmeal in the diets for common carp Cyprnus carpio fingerlings. The replacement levels of cluster bean meal protein in the diets were 25, 50, 75, and 100% of the total fishmeal protein. All diets were isonitrogenous at 33.1% crude protein and isocaloric at 4.8 Kcal/g. There were significant differences in the final individual weights, weight gains, specific growth rates (SGR %/d), feed conversion ratios (FCR), feed efficiency ratio (FER), protein efficiency ratios (PER), and feed intake among fish group ( P × 0.05). Common carp fed the diet containing 50% (CBM) exhibited comparable growth to those fed a fishmeal-based diet. Digestibility of protein, energy and lipid decreased with increasing levels of CBM above 50% of total fishmeal replacement in the diet. Incorporation of CBM in diets significantly affected the dry matter, protein, and energy of whole fish body. These results suggest that CBM can replace 50% of the fishmeal in diet for common carp.  相似文献   
95.
OBJECTIVE: To determine the survival time of Mycobacterium avium subsp paratuberculosis in amitraz-based cattle dip fluid derived from an active dip site in northern New South Wales. PROCEDURE: Following inoculation of triplicate 5 L containers with faeces (0.5 g/L) from a clinical case of bovine paratuberculosis, samples collected up to 8 weeks after inoculation were examined by conventional and radiometric culture. M a paratuberculosis colonies were enumerated on solid media. RESULTS AND CONCLUSIONS: M a paratuberculosis survived in amitraz cattle dip fluid for up to 2 weeks, but not 3 weeks. Where 1% of solids in dip fluid is derived from a clinical case of paratuberculosis, dip fluid may contain viable M a paratuberculosis for at least 2 weeks. These findings have implications for the management of cattle dip sites.  相似文献   
96.
The purpose of this experiment was to study the effects of Gymnadenia conopsea polysaccharide (GCP) extract on growth performance, meat quality and antioxidant function house-fed mutton sheep under oxidative stress, so as to provide experimental basis for extensive research and development of Gymnadenia conopsea and its extracts. Twenty 6-month-old healthy male Small-Tailed Han sheep with body weight of (35.0 ±4.0) kg were randomly divided into two groups. The experimental group (n=10) and control group(n=10). The whole experiment lasted for 42 d and was divided into 3 periods: the first 15 days were the blank period; the middle 15 days were the treatment period; the last 12 days were the observation period ofter modeling. From the first day of the treatment period, the control group was fed with basal diet, and the experimental group was fed pellet basal diet containing 30 mg·kg-1 GCP extract. On the 15th day of the treatment period, the sheep in each group were intraperitoneally injected with 10 mg·kg-1 Diquat solution according to sheep body weight(BW), and then fed for another 12 days. On the 1 st, 15th, 30th, 33rd, 36th, 39th and 42nd morning of the whole experimental period, fasting weight and blood samples were collected before feeding. The serum was separated and the antioxidant indexes (SOD, GSH-Px, T-AOC, MDA) in serum were determined. On the 42nd day of the whole experimental period, 5 sheep randomly selected from each group were slaughtered and meat samples were collected to determine the meat quality. The results showed that the addition of GCP extract to the diet of the sheep could increase the average daily feed intake (P<0.05). When the body was subjected to oxidative stress, the indexes of daily gain and antioxidant enzymes recovered rapidly on experimental group, the mutton drip loss decreased significantly, and the mutton sheer force increased significantly(P<0.05). The results indicated that GCP extract could improve the growth performance of mutton sheep, and alleviated the decline of growth performance and antioxidant performance caused by oxidative stress, and had a certain effect of antioxidant stress.  相似文献   
97.
对黄土沟壑区旱地条件下"龙王帽"、"白玉扁"的不同花型数量分布及遗传力进行了分析,结果表明:"龙王帽"的有效花比例高达91.8,具有较大的丰产潜力,宜作为旱地主栽品种;"白玉扁"有效花比例仅为41.2,雌蕊败育率较高,丰产潜力小,仅宜作为授粉品种;花型主要受遗传因素控制(遗传力高达0.99),环境影响较小.  相似文献   
98.
沙芥愈伤组织培养的初步研究   总被引:2,自引:0,他引:2  
采用沙芥种子作为无菌外植体来源时,以0.1升汞消毒10~12min的效果较好.下胚轴和子叶均在MS+2,4-D 0.01 mg·L-1+NAA 2 mg·L-1+6-BA 0.5 mg·L-1+3.0蔗糖+0.5琼脂(pH5.8)中可诱导出愈伤组织.愈伤组织的最佳继代培养基为MS+NAA 2mg·L-1+KT0.5 mg·L-1+3.0蔗糖+0.5琼脂(pH5.8).  相似文献   
99.
选取28日龄断奶的三元[杜×(大×长)]杂交仔猪96头,平均体重为(7.46±0.38)kg,按体重和 性别随机分为4个处理组,每个处理组3个重复,每个重复8头仔猪,公母各半。第1个处理组为空白 组,第2、3、4个处理组在相同的基础日粮中分别添加0.1%、0.2%和0.4%的甘露寡糖,研究甘露寡糖对断 奶仔猪肠道菌群的影响。结果表明:1、各实验组肠道大肠杆菌的浓度极显著低于对照组。2、第3组和 第4组其结肠、盲肠和直肠中双歧杆菌增殖显著。第2组中只有结肠中双歧杆菌显著高于对照组,但盲 肠和直肠中双歧杆菌增殖不明显。3、各个处理组肠道中乳酸杆菌的浓度与对照组相比差异不显著。  相似文献   
100.
氨气对肉鸡健康的影响及应对措施   总被引:1,自引:0,他引:1  
氨气是鸡舍内危害最大的气体,长期氨气应激不利于肉鸡的健康生长。加强对肉鸡舍氨气浓度的监测,研究氨气对肉鸡健康的影响以及减排措施对指导鸡舍氨气浓度的合理调控和健康养殖的发展具有重要意义。本文主要通过综述舍内氨气的来源,氨气对肉鸡生长性能、屠宰性能和肉品质、免疫功能、呼吸道、繁殖性能、福利等方面的影响以及舍内氨气的监测和减排措施,为深入研究氨气对肉鸡健康影响的作用机制以及合理调控肉鸡舍内氨气浓度提供参考。  相似文献   
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