Effects of tryptophan supplementation on plasma tryptophan and related hormone levels in heifers and dairy cows     

Kollmann MT  Locher M  Hirche F  Eder K  Meyer HH  Bruckmaier RM 《Domestic animal endocrinology》2008,34(1):14-24

This study was conducted to investigate the effects of rumen-protected tryptophan (125 g tryptophan per day) in heifers and dairy cows. Blood samples from dairy cows and heifers were collected for 24h in 3-h intervals on the day before tryptophan supplementation, on day 2, 5 and 7 of tryptophan supplementation, and in heifers additionally on d 14 after tryptophan supplementation was ceased. Plasma tryptophan, melatonin, serotonin, and prolactin concentrations were determined. Tryptophan plasma concentrations on d 5 were augmented at day (11:00 h) and nighttime (02:00 h), (P<0.05) in response to tryptophan supplementation in heifers by 119% and in dairy cows by 47%, respectively, as compared with d 0. Melatonin increased (P<0.05) in response to tryptophan supplementation in heifers, but not in cows. The effect of tryptophan supplementation on plasma tryptophan and melatonin was reversible as demonstrated in heifers on d 14 after cessation of tryptophan supplementation. Serotonin and prolactin in plasma did not respond to tryptophan supplementation. However, milk yield during morning milking increased significantly in tryptophan supplemented cows on d 1, 3 and 4 as compared to the day before tryptophan supplementation. Additional blood samples were taken during afternoon milking in cows at 1-min intervals for the analyses of oxytocin and prolactin on the day before the start and on d 7 of tryptophan supplementation. Milk flow curves were recorded during milking. No effect of tryptophan supplementation on the milking related release of oxytocin and prolactin and on any characteristic of milk flow was observed. In conclusion, tryptophan supplementation caused increased plasma tryptophan in cows and heifers and plasma melatonin in heifers. However, plasma serotonin, prolactin and oxytocin release in cows remained unchanged by tryptophan supplementation. Milk yield at morning milking increased slightly and transiently in response to tryptophan supplementation.  相似文献   

农业综合开发项目“先建后补”的几点思考     

Jinhu Agricultural Resource Development Bureau 《农机具之友》2010,(3):31-33

2008年,江苏省对宜兴、溧阳两市的省级丘陵山区农业综合开发项目进行了“先建后补”的试点．2009年又进一步扩大了试点范围。实践证明“先建后补”,一是可以简化项目管理程序,降低管理成本．提高工作效率,促进项目提前建设及早发挥效益;二是能充分调动业主投入农业综合开发的积极性,做大农业综合开发规模,形成多元开发的新局面。“先建后补”是一个管理机制创新,尚存在一些不容忽视的问题,结合近几年农业综合开发项目规划与管理的实践与探索。提出了具体的发展对策。  相似文献   

广西双季稻种植区涝灾量化评估技术研究     

黄海洪  谭宗琨  罗永明 《中国农学通报》2019,35(11):95-102

通过对广西南、中、北不同地形地貌代表县份历史典型涝灾年强降水过程的雨量分析,结果表明：涝灾当前日有效雨量与灾前6d有效雨量和的线性关系最为明显,达到95%置信检验。在此基础上,基于前人研究成果和历史灾情,构建了以涝灾当前日与灾前6d的有效雨量总和为致灾因子的农田涝灾等级指标,并以广西双季稻种植空间分布遥感信息为涝灾承灾体,采用智能格点雨量预报产品、乡镇自动观测站实时雨量的有效雨量值栅格图与之镶嵌、融合方法,实现广西双季稻洪涝灾前的量化评估。这一研究结果对政府及相关部门针对性开展防灾减灾,以及气象为农智慧化直通式服务有积极意义。  相似文献   

Effect of Nitrogen Applied Before Transplanting on NUE in Rice     

ZHENG Yong-mei DING Yan-feng WANG Qiang-sheng LI Gang-hua WU Hao YUAN Qi WANG Hui-zhi WANG Shao-hua 《中国农业科学(英文版)》2007,6(7):842-848

Nitrogen （N） application before transplanting, where N fertilizers are applied in seedling-bed and carried to the paddy field with seedlings, is a novel method proposed in this article aiming for improving nitrogen utilization efficiency （NUE） in rice. The effect of this method on mineral N distribution in the rhizosphere soil was investigated in a field experiment with a japonica variety, Ningjing 2, in seasons of 2004 and 2005. There were four levels of N applied 16 h before transplanting： zero N （NO）, 207 kg ha^-1 （NL）, 310.5 kg ha^-1 （NM）, and 414 kg ha^-1 （NH）. The result indicated that N fertilizer before transplantation had positive effect of increasing mineral N content in the rhizosphere soil of rice. Generally, N content in the rhizosphere soil of rice tended to increase with the amount of N fertilizer before transplanting, with the NH treatment having the largest effect. Additionally, N fertilizer before transplanting had significant influence on rice NUE and grain yield. Compared with other treatments, the NM treatment showed the largest influence, with basal-tillering NUE, total NUE, and grain yield being 15%, 12%, and 529.5 kg ha^-1 higher than those of NO treatment. This result indicated that N fertilizer before transplantation had positive effect on mineral N distribution in the rhizosphere soil of rice, thus improving NUE and grain yield.  相似文献   

稻麦割前脱粒技术的研究     

王林  郭超  付君 《农业装备与车辆工程》2011,(9):1-2,9

我国传统联合收获机的收获工艺大多是全喂入方式,先割后脱,其割台结构是通过拨禾轮、扶禾器即将带穗作物茎杆切割下来,输送到脱粒和清选装置。脱粒、清选负荷很大。尤其是在作物含水量大时,极易造成堵塞、脱粒不净、麦粒难以分离等现象。使得利用机械收获的工作效率受到限制。为解决传统联合收获机的收获工艺,割前脱粒收获工艺成为收获机械研究的一个方向。  相似文献   

河南省弱春性小麦冬前壮苗叶龄指标的确定     

李巧云  尹钧  刘万代  李磊  周苏玫 《河南农业科学》2010,(10)

选用3个有代表性的弱春性小麦品种,在河南省18个试验点种植,研究了冬前积温(播期)对产量的影响及冬前壮苗叶龄指标的确定。结果表明,冬前积温与小麦产量存在二次回归关系,冬前积温在590℃时产量最高,表明此积温下的播期是河南省弱春性小麦的适宜播期。随冬前积温增加(播期提早),弱春性小麦冬前长1片叶子所需要积温增加,冬前积温350～770℃,长1片叶子所需要的积温在57～84℃。根据适宜冬前积温长1片叶子所需积温推算,河南省弱春性小麦冬前应处于六叶一心期,这样既能充分利用冬前积温获得高产,又能保证弱春性小麦安全越冬。  相似文献   

椴树杀卵机制初探   总被引：4，自引：2，他引：2  

田润民  张玉凤  张全如  于静波  张泽新 《内蒙古林业科技》2005,(2):16-20

椴树有吸引光肩星天牛产卵又具有杀其卵之功能。显微解剖椴树产卵室和受害韧皮组织，观察其卵室和卵的变化情况，揭示了韧皮射线与髓射线流出物不仅作用雏形卵室，而且直指卵表面及卵孔。椴树杀卵机制有2种，化学作用和物理作用：其一，刻槽部韧皮组织分泌物对天牛产卵前分泌物有抑制作用。对刻槽内产卵线有愈伤之功效；其二，由于产卵前分泌物不能腐蚀卵室壁，雏形卵室壁不被固定，卵室壁愈合回缩，卵被禁锢其中挤压变形直至死亡：研究椴树韧皮分泌物其目的则是提取、利用该物质用于非抗树种提高抗虫性和免疫力。  相似文献   

割前脱粒中收割禾秆的研究   总被引：2，自引：1，他引：1  

徐树来  李勃海  赵莹  贾福龙 《黑龙江八一农垦大学学报》2000,12(1):65-68

近年来国内外学者对割前脱粒收获工艺进行了大量的研究,但如何处理硫脱后仍站立于田间的禾秆,仍未能很好地解决。本文分析了禾秆处理的几种方案,研究了切割及放铺机的合理工况,对于禾秆处理问题的解决具有积极的意义。  相似文献   

提高生猪屠宰检疫质量的思考与建议     

李平  王学文  殷宪强 《宁夏农林科技》2014,(8):69-70

为进一步提高生猪屠宰检疫质量,作者结合多年工作经验,指出检疫工作需要掌握的技术环节和注意事项,并针对存在的问题提出了建议。  相似文献   

牡丹江市膜外栽烟种植技术及优势     

郭峰  郑锟 《现代农业科技》2014,(19):55-56

对牡丹江地区,先覆膜后栽烟的膜外栽烟种植技术进行了详尽阐述,指出了该技术操作过程中需要注意的技术难点和操作方法。将该种植技术同传统种植方法进行比较,以牡丹江市该种植技术的应用为例,详细分析了其在提高烟《质量和产量等多方面的优势。  相似文献