露天煤矿排土场复垦区不同植被类型枯落物持水特性研究

为揭示露天煤矿排土场复垦区不同植被类型水土保持效益,选取刺槐林地、榆树林地、混交林地(刺槐和榆树混交)、灌木林地(紫穗槐)和荒草地5种典型复垦植被下的枯落物作为研究对象,采用室内浸水法对5种植被类型枯落物的持水特性进行研究。结果表明:5个样地的枯落物厚度、蓄积量均表现为:乔木林地灌木林地荒草地,枯落物厚度在0.80~1.64cm之间,总蓄积量在0.72~7.51t/hm~2之间;枯落物最大持水量和有效拦蓄能力均表现为刺槐林地最大,枯落物最大持水率为145.58%~206.58%,最大持水量为13.11~123.98t/hm~2,有效拦蓄率为119.74%~166.05%,有效拦蓄量为10.09~98.76t/hm~2;林地枯落物持水量与浸泡时间的关系为Q=aln t+b;枯落物在0~1h内吸水速率最大,1~4h内吸水速率急剧下降,随后下降幅度逐渐减小,枯落物吸水速率与浸泡时间关系式为:V=atb。研究结果可为评价露天煤矿排土场不同类型复垦区枯落物层水源涵养效益提供参考,为排土场植被恢复与重建提供科学依据。     

辽西低山丘陵区坡地砾石含量及粒径对土壤入渗性能的影响

基于室内土柱模拟试验对比分析辽西低山丘陵区坡地不同粒径及砾石含量的土壤入渗规律,并采用4种模型分析了含砾石土壤对传统土壤入渗模型的适用性。结果表明:粒径一定时,随砾石含量的增加土壤累积入渗量减少,随累积入渗量的增加土柱湿润锋变化速率由小变大;砾石含量小于20%时,湿润锋前进到一定深度下,土壤累积入渗量随粒径的增加而增大;当砾石含量增大到一定值时,砾石含量相同直径不同的土壤累积入渗量与湿润锋随时间的变化基本无差异。累积入渗量与湿润锋推进距离呈良好的线性关系。利用Green-Ampt模型、通用模型、Horton模型和Kostiakov模型对入渗率与入渗历时的关系进行拟合,其中砾石含量为5%时,Horton模型拟合效果最好,砾石含量为10%~30%时通用模型适用性更强,Horton模型拟合效果最差,其他模型拟合效果因砾石含量及粒径等因素的不同而异。     

Fosl2基因的研究进展

Fosl2(Fos-like antigen 2)属于活化因子蛋白1(activator protein-1,AP1)转录因子家族中的一种,在多种组织中均有显著表达,对哺乳动物的生长发育、生殖性状、免疫应答等起到重要的作用。近年来,随着研究的深入,人们发现Fosl2基因与脂肪代谢、骨骼发育及疾病和癌症的发生有着重要联系。作者综述了Fosl2基因的结构与组织表达分布,同时概述了其在脂肪代谢、骨骼发育、癌症发生及眼部发育等重要生理过程中的作用,并对其生物功能进行了展望,以期为更深层次的研究和提高动物的生长发育性状提供参考。     

4个猪种的PRLR基因多态性与产仔性能的关联分析

采用PCR-Alu Ⅰ-RFLP技术检测了豫南黑猪、杜洛克猪、长白猪和大约克夏猪4个猪种的PRLR基因位点多态性,并采用最小二乘法分析其对产仔数影响的遗传效应.结果表明:4个猪群中均存在A和B2个等位基因.其中A等位基因在豫南黑猪、杜洛克猪和长白猪群中占优势,B等位基因在大约克夏猪中占优势.在豫南黑猪中不同基因型母猪的总产仔数和产活仔数的差异均未达到显著水平(P＞0.05),但呈现AA＜AB＜BB的趋势.引进猪种的经产母猪不同基因型对产仔数有显著影响(P＜0.05).     

Correlation Analysis for Feeding Habits,Morphological Parameters,Weight Parameters and Abdomen Meat Percentage of Procambarus clarkii北大核心CSCD

This experiment was conducted to determine the food source and trophic level of Procambarus clarkii from rice-crayfish field by stable isotope method, and to analyze the correlation between feeding habits, morphology parameters, weight parameters and abdomen meat percentage of P. clarkii. normal (62 individuals) and claw reborned (6 individuals) samples of P. clarkii were collected from the rice-crayfish continuous production field in Zhanjiang. At the same time, vascular plants, snails, as well as diet samples were collected. The stable carbon and nitrogen isotope values of all collected samples were analyzed, the contribution rate of diet, Elodea nuttallii and Potamogeton crispus to the abdomen meat growth of P. clarkii were calculated using a stable isotope mixing model including element concentration, and the trophic levels of P. clarkii and Pomacea canaliculata were calculated by stable nitrogen isotope model. The correlation between stable carbon and nitrogen isotope characteristics (δ13 C and δ15 N) of abdomen meat, morphological parameters (body length, full length, carapace length, carapace width, tail fan length) and weight parameters (body weight, abdomen meat weight, claw weight, claw body ratio) of the collected crayfish were analyzed. The results showed as follows: 1) the collected crayfish included 30 female and 32 male individuals, and the body weight of these crayfish ranged from 3.40 to 29.35 g, average (14.05±6.26) g. The model calculation results showed that diet contributed 63.40% of biomass, 62.28% of carbon and 75.15% of nitrogen to the abdomen meat growth of P. clarkii. 2) In this study, Cipangopaludina cahayensis was used as the baseline for primary consumers, and the calculated trophic level of P. clarkii was 2.20, while the trophic level of P. canaliculata was 2.68. 3) The abdomen meat percentage of P. clarkii (<15 g) collected were extremely negatively correlated with the claw weight and the claw body ratio (P<0.01), indicated that the growth of the claws directly affected the muscle growth of these crayfish. The abdomen meat percentage of P. clarkii (>15 g) were not significantly correlated with the claw weight and the claw body ratio (P > 0. 05), but were extremely positively correlated with the abdomen meat weight and the δ13C value (P<0.01) . It showed that the utilization of diet by these crayfish had become a key factor in determining their abdomen meat percentage. 4) There was a significant negative correlation between the claw weight and the δ13C value (P<0.05) in all collected normal crayfish. It could be inferred that individuals with well-developed claws tend to eat more P. crispus which with lower δ13C value. When the diet was sufficient, the lack of claws did not significantly affect the feeding and growth of P. clarkii (P<0.05) . It is concluded that there are significant correlation between feeding habits, morphology parameters, weight parameters, and abdomen meat percentage of P. clarkii, the diet is the main nutrient source for the abdominal muscle growth of P. clarkii in this study, but even when the diet is sufficient, P. clarkii still feeds heavily on aquatic plants. Traditional methods of stable nitrogen isotope trophic level study may not suitable for aquaculture ecosystems which are strongly influenced by diets. The results of this study can provide basic data for the genetic selection of P. clarkii and the ecological research on the integrated breeding model of rice-crayfish. © 2023 Chinese Journal of Animal Nutrition. All rights reserved.     

胎次、季节对淮南猪繁殖性能的影响

为了解不同胎次、季节对淮南猪繁殖性能的影响,对878头淮南猪2 131窝的繁殖记录进行统计分析。结果表明:随着母猪胎次的增加,淮南猪的产仔性能呈现先升高再稳定最后降低的趋势。在第4胎时,其总产仔数显著高于第1胎(P0.05),活仔数和健仔数显著高于第1胎与第7胎及7胎以上的母猪(P0.05)。在第5胎时,淮南猪的死胎数最多,显著高于1～3胎(P0.05)。在第6胎时淮南猪的木乃伊胎数最多,显著高于3、4、5、7胎及7胎以上(P0.05)。在配种季节方面,秋季配种时,其总产仔数、活仔数和健仔数最多,显著高于春季(P0.05)。在分娩季节方面,冬季分娩时,其总产仔数、活仔数和健仔数最多,显著高于秋季(P0.05)。研究表明,淮南猪在第2～6胎时繁殖性能较优,并且在秋季适宜配种,冬季适宜分娩。     

紫色土坡地果草种植模式的水土流失特征研究

紫色土坡耕地是三峡库区重要的土地资源。以研究降雨强度对紫色土坡地产流产沙的影响为基础,以紫色土坡地示范推广的果草模式为研究对象,对其水土流失特征进行了野外定点监测研究。研究结果表明:(1)短历时、高强度降雨对紫色土坡地的产流产沙影响最强烈,降雨历时与产流产沙存在明显的负相关,而雨强参数与产流产沙则存在明显的正相关;(2 )在降雨特征参数中,平均雨强是反映紫色土坡地径流系数、泥沙量和径流含沙量的最好特征参数,I3 0 则能最好的反映紫色土坡地径流量的变化;(3)在不同降雨强度下,果草模式对产流量、径流系数、产沙量和径流含沙量都有非常明显的减少或降低作用,特别在低强度降雨时,其减水减沙效应更明显,种植年限对其效应也有影响;(4)在短历时、高强度典型次降雨情况下,果草模式具有明显延迟产流时间和延缓产流过程的作用;(5 )果草模式降低了紫色土降雨前后表土养分的衰减,减少了表土养分的流失;(6 )果草模式对速效养分的流失具有较好的减弱作用,因而其对保持地力,提高土地生产力具有较好的作用     

三峡库区春玉米水肥耦合效应研究

三峡库区春玉米盆栽水肥耦合试验研究结果表明,水分胁迫导致玉米株高和叶面积指数降低,以拔节期受到影响最大;玉米产量与生物量呈显著正相关关系,产量与根重无显著正相关关系;水氮耦合效应显著,适宜水分和中氮处理下玉米的产量最高,玉米生长发育对氮肥的吸收存在一定的阈值,过多施用氮肥会加剧土壤干旱和作物干旱,水和钾耦合效应对玉米产量影响不显著;水分是影响玉米产量的主导因素,其次是氮效应和钾效应。     

排土场边坡根系分布及其对土壤抗冲性的影响

以海州露天矿排土场边坡为研究对象,采用改进的原状土水槽冲刷法,研究了排土场边坡根系分布及其对土壤抗冲性的影响。结果表明:排土场边坡根密度平均每为8.46个100 cm-2,根系长度随根系径级的增大而不断减小,根系生物量随根系径级总体上呈下降趋势,土壤中根系以根径0.5 mm须根为主;土壤抗冲指数与时间之间存在极显著的指数回归关系;土壤抗冲指数大部分位于0.06~0.12 min g-1之间,这部分所占坡面总面积的83.02%,沿坡长方向土壤抗冲指数表现出先减小后增大的趋势,并在3个坡位之间存在极显著差异;根系对土壤抗冲性能强化值范围在0.01~0.05 min g-1之间,强化百分率为16.67%~83.33%,表明在相同径流冲刷强度与相同冲刷时间条件下,根系对于增强土壤抗冲性能的效果明显。     

猪初乳免疫球蛋白研究进展

衡量猪场总体效益的重要指标是母猪每年所产的断奶仔猪数。近十年来,在全世界断奶前仔猪的死亡一直在10%以上,这给猪生产者造成了重大损失,仍然是困扰当前养猪业发展的一大难题,也是目前急需解决的问题之一。影响断奶前仔猪死亡的一个关键因素就是初乳中母源抗体IgG的含量不足,使新生仔猪免疫力低下易感疾病而死亡。本文讨论了初乳、初乳中母源抗体IgG的形成机制、母源抗体IgG对新生仔猪的影响、母源抗体IgG的影响因素。