氮素水平对单作和间套作小麦玉米叶片叶绿素含量及品质的影响   总被引：10，自引：0，他引：10  

何承刚  黄高宝  姜华 《干旱地区农业研究》2004,22(3):32-34

以间套作小麦玉米、单作小麦和单作玉米为研究对象,通过田间试验研究了氮素水平对单作和间套作小麦玉米叶片叶绿素及品质的影响。主要结果为:在同一施氮水平下,间套作小麦旗叶叶绿素含量大于相应单作;单作和间套作小麦开花期旗叶叶绿素含量和蛋白质含量、沉淀值之间都呈显著正相关(r分别为0.960*,0.948*,0.968*,0.957*)。在相同施氮水平下,单作玉米叶绿素含量高于相应间套作玉米;单作和间套作玉米孕穗期叶绿素含量与其蛋白质含量之间也呈显著正相关(r分别为0.861*和0.870*)。  相似文献   

99%矿物油乳油(绿颖)防治茶橙瘿螨药效试验研究   总被引：1，自引：1，他引：1  

宁伟文  潘晓皖  胡敏 《农药科学与管理》2004,25(6):21-23

1地连续2年的药效试验表明，99％矿物油乳油施药后3d对茶橙瘿螨效果较明显，50、150倍液防效均超过80％，250倍液防效为73．6％，施药后7、14、21d，2种较高剂量的99％矿物油乳油防效均超过80％．最高达97％以上。在推荐施用浓度范围内，药效高，持效性好．对茶树和天敌生物无不良影响。  相似文献   

Bt玉米对中红侧沟茧蜂发育的间接影响及室内行为研究     

贠桂玲  邓曙东  张青文  徐环李  蔡青年 《植物保护》2004,30(5):23-26

利用Y-型嗅觉仪研究了中红侧沟茧蜂(Microplitis Mediator Haliday)对Bt玉米、常规玉米、粘虫幼虫和其虫粪及虫害苗挥发物的行为反应,同时研究了Bt玉米对中红侧沟茧蜂发育的影响。结果表明,两种玉米健康植株的挥发物对中红侧沟茧蜂均有引诱作用;中红侧沟茧蜂对两种玉米的健康植株及机械损伤株挥发物之间的选择性无显著差异;相对于Bt玉米,中红侧沟茧蜂更趋向于选择常规玉米的虫伤苗及玉米-粘虫幼虫-虫粪混合物的挥发物。与对照(寄生于取食常规玉米粘虫的中红侧沟茧蜂)相比,寄生于取食Bt玉米粘虫幼虫的中红侧沟茧蜂幼虫历期延长,出茧率、茧重、羽化率、蜂重均有显著降低,茧历期、蜂历期则差异不显著。  相似文献   

现代集约化肉羊业主要关键技术研究与应用     

赵有璋  李发弟  姚军  张子军  王玉琴  蔡原  陈亚明  祝淑英  李永连  赵宗蕾  王敏芬  冯涛  郭健  杨富民 《中国草食动物》2005,25(2):3-9

专门化肉用种羊选定、引进后，通过适应性研究，在较大规模养羊业生产实践中。对现代集约化肉羊业的主要关键技术进行研究、完善和创新，组装集成并应用于生产。技术研究应用结果既为市场提供了大批专门化肉用种羊和优质安全的杂种肉羊，取得了高水平的研究成果及显著的经济效益和社会效益．又为我国目前正在迅速发展的集约化肉羊业提供了可靠的技术支持和理想的生产模式：从适宜的专门化肉羊品种到运用高效母羊快速扩繁技术．建立和完善有效的肉羊杂交利用体系，普遍应用种羊鲜、冻精生产大批肉用杂种羔羊，种植高产优质饲草及其科学加工调制和利用．建立严格兽医防疫制度．实行放牧 补饲或全舍饲的精细管理和集约化育肥，至生产优质、安全、标准肉羊，获得显著的经济效益和社会效益。  相似文献   

高+Gx过载作用对恒河猴肺脏的影响     

郝俊峰  吴斌  赵德明  宁章勇  王传武  秦秀慧 《中国兽医学报》2005,25(4):400-402

15只健康恒河猴于清醒状态下，在动物离心机上经受相应峰值( 1Gx、 15Gx、 18Gx、 21Gx)的抛物线型过载作用后，按要求在过载后不同时期剖解，大体观察、取材，进行病理形态学的定性研究。结果显示：(1)眼观病变。 15Gx组、 18Gx组和 21Gx组在过载作用后即刻肺脏出现了不同程度的气肿、萎陷、淤血和出血点或斑；恢复组可见肺脏边缘有不同程度气肿区域，肺脏的背面呈暗红色；在各叶的背面均可见大小不等、多少不一的暗红色出血点或斑。(2)光镜下可见各急性实验组动物的肺脏呈现不同程度的气肿区和萎陷区，肺泡壁毛细血管扩张充血，肺泡腔内有浆液和红细胞渗出； 21Gx组还出现了血管内溶血、细支气管粘膜脱落和出血等，肺脏的病理损伤随G值升高而明显加重； 15Gx作用造成的肺脏损伤在1个月后基本恢复。而 21Gx作用后1个月肺脏的损伤尚未恢复，且出现了白细胞浸润、浆液渗出和增生等炎症反应。因此，高 Gx过载可引起猴肺脏明显的病理性损伤，其中 15Gx造成的损伤相对较轻，且容易恢复，而 21Gx造成的损伤严重，且难以恢复。  相似文献   

不同轮作序列对旱地胡麻土壤有机碳稳定性的影响   总被引：1，自引：0，他引：1  

刘栋  崔政军  高玉红  剡斌  张中凯  吴兵  谢亚萍  牛俊义 《草业学报》2018,27(12):45-57

为了探索陇中黄土高原半干旱丘陵沟壑区胡麻轮作序列对土壤碳库的影响,2012-2016年通过4年定位试验,以连作为对照,研究了不同胡麻频率下的轮作序列(F:休闲;PWFW:25%Flax、马铃薯-小麦-胡麻-小麦;WFWP:25%Flax、小麦-胡麻-小麦-马铃薯;FWPF:50%Flax、胡麻-小麦-马铃薯-胡麻;WPFF:50%Flax、小麦-马铃薯-胡麻-胡麻;FFFF:100%Flax、胡麻-胡麻-胡麻-胡麻)对土壤团聚体、总有机碳(TOC)、土壤颗粒有机碳(POC)、土壤微生物碳(MBC)和氮(MBN)的影响。结果表明,休闲、不同轮作序列和低胡麻频率显著增加了030 cm土层<0.25 mm粒级的土壤团聚体含量、TOC和POC含量,而随胡麻频率的增加三者的含量呈下降趋势。其中,25%Flax处理下土壤团聚体含量较播前和休闲处理分别显著增加了2.02%4.04%和9.56%11.73%;土壤有机碳(SOC)较连作显著增加5.95%7.48%。50%Flax处理下胡麻位置对土壤SOC影响显著,且轮作(FWPF)显著高于连作(WPFF)。060 cm土层土壤SOC含量表现为休闲>播前≈25%Flax>50%Flax>100%Flax。与连作相比,轮作显著提高了010 cm土层土壤TOC和POC含量,呈现表层富集现象。土壤POC含量表现为25%Flax≈休闲>50%Flax>100%Flax。此外,轮作换茬显著增加了土壤MBC含量,且随着胡麻频率的增加,030 cm土层土壤MBC含量逐渐降低。与播前、休闲、轮作相比,连作显著降低土壤微生物碳氮比,50%Flax(WPFF)轮作序列和土层深度对土壤有机碳和微生物量的互作效应显著。综合来看,休闲可以显著改善土壤理化性状,25%胡麻频率的轮作序列利于保持土壤团聚体稳定性,增加土壤TOC、SOC和POC含量,而50%Flax轮作序列(WPFF)能够提高土壤微生物量和微生物碳氮比。表明25%胡麻频率的轮作序列均可维持土壤有机碳的稳定性,是旱地胡麻比较理想的轮作序列。  相似文献   

日粮中添加牛至油对河西绒山羊育肥性能的影响研究     

姜辉  雷赵民  焦婷  刘婷  王建福  李冲  唐德富  张建强 《草业学报》2018,27(11):142-149

牛至精油对家畜生产性能和免疫力的提高有重要的影响。通过在日粮中添加牛至精油育肥河西绒山羊,研究其对河西绒山羊生长性能、屠宰性能及胴体品质的影响。对照组饲喂基础日粮,试验组在饲喂的基础日粮中分别添加4和7 g宜生饲宝(含牛至精油的添加剂),4和7 g宜生饲宝中牛至精油的含量分别为52和91 mg。对照组和试验组均为同月龄、同体重的河西绒山羊羯羊,试验组和对照组均设3个重复,每个重复5只羊。育肥期为90 d,每30 d为1个阶段。试验结果表明:育肥全期,对照组、4 g组和7 g组河西绒山羊平均日增重分别为96.30、172.22和169.82 g·d^-1,4 g组和7 g组分别显著高于对照组(P<0.05),4 g组和7 g组无显著差异(P>0.05);屠宰性状,胴体重对照组、4 g组和7 g组分别为20.24、24.18和23.90 kg,无显著差异(P>0.05),屠宰率对照组、4 g组和7 g组分别为48.86%、51.21%和51.56%,4 g组和7 g组分别显著高于对照组(P<0.05),4 g组和7 g组无显著差异(P>0.05),胴体净肉重对照组、4 g组和7 g组分别为12.90、16.27和15.99 kg,4 g组和7 g组分别显著高于对照组(P<0.05),4 g组和7 g组无显著差异(P>0.05);肉质性状,大理石纹4 g组和7 g组分别显著高于对照组(P<0.05),4 g组和7 g组无显著差异(P>0.05),pH、熟肉率、失水率、嫩度、蒸煮损失对照组、4 g组、7 g组间均无显著差异(P>0.05)。日粮中添加牛至油可以显著提高河西绒山羊的育肥性能,本试验日粮中添加4 g宜生饲宝(含牛至精油52 mg)效果最佳。  相似文献   

Tall oil fatty acid inclusion in the diet improves performance and increases ileal density of lactobacilli in broiler chickens     

K. Vienola  G. Jurgens  J. Vuorenmaa  J. Apajalahti 《British poultry science》2018,59(3):349-355

1. Studies were conducted with tall oil fatty acids (TOFA) to determine their effect on broiler chicken performance and ileal microbiota. TOFA, a product originating from coniferous trees and recovered by fractional distillation of side-streams from pulp production, mainly comprises free long-chain fatty acids (~90%) and resin acids (~8%). Conjugated linolenic acids and pinolenic acid are characteristic fatty acid components of TOFA.

2. TOFA products at 750 mg/kg feed were tested in two 35-day broiler chicken trials, each using a wheat soya-based diet and with 12 replicate pens per treatment. In both trials, TOFA improved body weight gain at all time points (P < 0.001) and feed conversion efficiency during the first 21 days (P < 0.01). Two different dry TOFA formulations (silica carrier and palm oil coating) were tested and showed performance effects similar to liquid TOFA.

3. Ileal digesta of the broiler chickens was analysed for total eubacteria, Lactobacillus spp., Enterococcus spp., Escherichia coli and Clostridium perfringens on days 14 and 35. TOFA significantly increased total eubacteria and lactobacilli density on day 14 (P < 0.05). There was a significant positive correlation between these bacterial groups and broiler body weight on day 14 (P < 0.01).

4. A numerical reduction in C. perfringens was observed. In vitro growth inhibition studies showed that C. perfringens was strongly inhibited by 10 mg/l TOFA (P < 0.001), while common lactobacilli were resistant to >250 mg/l. The in vitro results were thus in line with in vivo observations.

5. The mechanisms behind the bacterial shifts and their role in performance improvement are unknown. Further purification of TOFA components is needed to identify the effective agents.  相似文献   

Performance,rumen fermentation and blood metabolites of dairy calves fed starter mixtures supplemented with herbal plants,essential oils or monensin          下载免费PDF全文

M. Akbarian‐Tefaghi  E. Ghasemi  M. Khorvash 《Journal of animal physiology and animal nutrition》2018,102(3):630-638

This study evaluated the supplementation effects of three herbal plants (thyme [THY], eucalyptus [EUC] and celery [CEL]), a commercial phytogenic additive ?containing essential oils (PFA‐EO, Digestarom^® P.E.P.) and monensin (MON) in calf starter on performance, rumen fermentation and blood metabolites during pre‐ (days 3–55) and post‐weaning (days 56–70). Sixty‐six Holstein dairy calves (3 days of age, 41.2 ± 3 kg of BW) were allocated to one of six starters supplemented with: (i) no additives (CON), (ii) MON (30 mg/kg), (iii) THY (23 g/kg), (iv) CEL (23 g/kg), (v) EUC (23 g/kg) and (vi) PFA‐EO (3 g/kg). All the calves were offered starters ad libitum plus 6 L of whole milk daily. Starter intake tended to be the highest in calves fed PFA‐EO and THY; intermediate in calves fed CON, MON and EUC; and the lowest in those fed CEL. Average daily gain (ADG) and feed efficiency (FE) remained unaffected by dietary treatments during the pre‐weaning. During the post‐weaning period, ADG and FE ?were greatest in calves fed EUC followed by those fed CON, MON, PFA‐EO and THY, and then in those fed CEL. No differences were observed among the treatments in skeletal growth, faecal score, rumen pH or ammonia‐N concentration. Compared to calves fed CON and MON, those fed the herbal plants or PFA‐EO tended to recorded higher molar proportions of acetate and butyrate, and the acetate: propionate ratio. Blood malondialdehyde level did not differ among treatments, but calves on CON had the highest glucose concentration, and those fed PFA‐EO recorded the highest value for β‐hydroxyl butyrate on day 70. In conclusion, the results indicate that the three herbs and PFA‐EO are capable of modulating some of the rumen fermentation parameters and blood metabolites as well as eucalyptus could potentially be a better alternative to monensin for improving post‐weaning performance.  相似文献   

Efficacy of essential oils combination on performance,ileal bacterial counts,intestinal histology and immunocompetence of laying hens fed alternative lipid sources          下载免费PDF全文

Asma Mousavi  Amir Hossein Mahdavi  Ahmad Riasi  Masoud Soltani‐Ghombavani 《Journal of animal physiology and animal nutrition》2018,102(5):1245-1256

This study was carried out to assess the effects of a blend of herbal essential oils (namely Thymus vulgaris, Mentha piperita, Rosmarinus offisinalis and Anethum graveolens) and different dietary lipid sources on the performance, ileal bacterial enumeration, intestinal histological alterations and immune responses in laying hens. For this purpose, a total of 150 laying hens were randomly allocated to six experimental treatments with five replicates of five birds each. Dietary treatments consisted of three levels of a mixture of essential oils (0, 100 and 200 mg/kg) and two sources of lipid (soybean oil and fish oil containing different ratios of n‐6 to n‐3 fatty acids) fed to the animals during an 80‐days feeding trial. Findings indicated that dietary administration of fish oil not only increased significantly the spleen relative weight (p < 0.01) and the antibody titre against Newcastle virus (p < 0.05) but also led to reductions in liver relative weight (p < 0.05) and feed conversion ratio (p < 0.05). Moreover, the mixture of herbal essential oils brought about declines in hepatic relative weight, heterophile to lymphocyte ratio (p < 0.05) and intestinal pathogen populations (p < 0.01). Mention must also be made of the improvements it made in spleen weight (p < 0.01), antibody titres against SRBC (p < 0.01) and Newcastle virus (p < 0.05), villus height to crypt depth ratio (p < 0.01), goblet cell numbers (p < 0.05), lamina propria lymphatic follicle diameters (p < 0.01) and feed conversion ratio (p = 0.06). It may be claimed that the enhancements observed in the performance of laying hens fed fish oil and 200 mg/kg of the blend of essential oils could have potentially been associated with improved intestinal health indices as well as cellular and humoral immune responses.  相似文献