饲养模式对肉鸡腿骨健康及抗氧化性能的影响

本试验旨在探讨饲养模式对肉鸡腿骨尺寸、骨密度、骨强度、骨组织细胞因子含量以及抗氧化性能的影响。饲喂200只7日龄混合性别的817白羽肉鸡，随机分为笼养组和地养组，每组设置10个重复，每个重复10只鸡。试验期42 d，试验结束后采集肉鸡的左腿胫骨和股骨测定骨骼尺寸、骨密度和骨强度，并采集右腿胫骨骨骺和肝脏样品，分别用于测定细胞因子和抗氧化性能。结果显示：两组肉鸡之间的腿骨尺寸和骨面积没有显著差异，但是地养组肉鸡股骨和胫骨的骨矿含量相对于笼养组肉鸡有上升趋势（0.05相似文献   

Effects of Dietary Sodium Acetate on Lactation Performance and Rumen Microbiota of Dairy Goats北大核心CSCD

This experiment was conducted to investigate the effects of dietary sodium acetate on lactation performance and rumen microbiota of dairy goats. Fifteen healthy Xinong Saanen dairy goat ewes with similar body weight of (53.54±3.07) kg, the same parity (2 parities) and in mid-lactation [(60±5) d] were randomly divided into 3 groups with 5 replicates in each group. Dairy goats in the control group were fed a basal diet, and those in the experimental groups were fed the basal diet supplemented with 30 (experimental group I) and 60 g/ (d.head) (experimental group II) sodium acetate, respectively. The pre-trial period lasted for 7 days and the experimental period lasted for 21 days. The milk yield of dairy goats was recorded during the experiment. At the end of the experiment, milk samples were collected to analyze the changes in milk composition, and rumen contents of dairy goats were collected from two groups (control group and experimental group II) with significant differences in milk fat percentage. Gas chromatography and 16S rDNA sequencing technology were used to analyze the rumen fermentation parameters and rumen microbial composition and structure of dairy goats. The results showed as follows: 1) compared with the control group, dietary sodium acetate extremely significantly increased the daily milk yield of dairy goats (P<0.01), and the daily milk yield in experimental groups I and II was increased by 0.29 and 0.22 kg, respectively (P<0.01); in experimental group II, the milk fat percentage was significantly increased by 1.30 percentage points (P<0.01), and the non-fat solid content in milk was increased by 3.10% (P>0.05). 2) Compared with the control group, the rumen butyric acid content of dairy goats in experimental group II was significantly decreased (P<0.01), and there was no significant difference in rumen pH, the other volatile fatty acid content and acetic acid to propionic acid ratio (P>0.05). 3) Compared with the control group, the Sobs index, Chao1 index and Ace index of rumen microbiota in experimental group II were significantly increased (P<0.05); the results of similarity analysis (ANOSIM) also showed that there were significant differences in the structure of rumen microbiota between the two groups (P<0.05). 16S rDNA sequencing results showed that at the phylum level, Bacteroidetes and Firmicutes were the dominant phyla in the rumen of the two groups of dairy goats; at the genus level, Prevotella_1 was the dominant genus in the rumen. Compared with the control group, the relative abundances of Ruminococcus_1, Ruminococcaceae_UCG-005, Prevotellaceae_UCG-004 and Lachnoclostridium_12 in rumen of dairy goats in experimental group II were significantly increased (P<0.05), while the relative abundances of Succiniclasticum and Methanobrevibacter in rumen was significantly decreased (P<0.05). 4) The results of correlation analysis showed that rumen microbiota was correlated with daily milk yield, milk fat percentage, milk protein percentage and non-fat solid content of dairy goats. In conclusion, dietary 60 g/ (d.head) sodium acetate can significantly increase the daily milk yield and milk fat percentage, significantly reduce rumen butyrate content, and improve the lactation performance of dairy goats by improving rumen microbial composition and structure. © 2023 Authors. All rights reserved.     

化肥减量配施有机肥和菌剂对辣椒产量、品质和养分累积的影响

以"羊角红1号"辣椒为试材,采用田间小区试验,探究肥料的减肥增效潜力,在保证产量以及品质的前提下实现科学施肥,以期为连作区的安全高效施肥提供参考依据.结果 表明:1)与农民常规施肥方式相比,减施氮、磷、钾养分55.9％、75.8％、56.8％,并未造成辣椒产量下降,其中牛粪部分替代化肥并配施菌剂(T6)处理产量最高,增幅为12.1％,该处理的病果率降低13.03个百分点;2)推荐施肥提高了肥料偏生产力,其中T6处理增幅最大;3)推荐施肥处理显著提高了辣椒的品质,包括辣椒素以及果实维生素C含量;4)农民常规施肥辣椒根、茎、叶和果实中氮磷钾均处于较高水平,但与其它处理间差异不显著;化肥减量配施有机肥与菌剂对土壤的理化性质影响不显著.综合考虑产量、病果率、肥料偏生产力、辣椒品质,在辣椒连作种植区,适宜的安全高效施肥模式是在化肥减量的基础上,采用牛粪部分替代化肥并配施微生物菌剂.     

关于大众化教育进程中因材施教的思考

高等教育大众化进程的加快，学生之间的个体差异增加，必然给高校的教学工作带来很大困难。高校应采取有效措施，促进每一个人健康、和谐地发展。该文从教学管理制度、人才培养方式、校园文化氛围三个方面提出了因材施教的思路与措施。     

成县核桃良种筛选及繁育技术研究结果总结

核桃是成县主要经济树种,为了发展核桃产业,成县从1994年以来引进全国核桃良种83个,在不同类型区进行了优良品种的筛选试验和苗木繁育嫁接技术研究。着重对筛选出的8个早实品种和5个晚实品种的表现及嫁接繁育技术研究结果进行报道。     

26种木莲属植物的园林观赏价值评价*

采用层次分析和加权评分相结合的评价系统,以木莲属植物的园林景观应用为目的,根据观赏价值、资源潜力、生物学特性三大类13个指标,对26种木莲属植物的园林观赏价值进行评价。筛选出适宜华南地区园林应用的种类,有亮叶木莲、马关木莲、木莲、大叶木莲、海南木莲、毛桃木莲、乳源木莲、大果木莲等,评价结果与实际情况较为一致。此评价可以为育种目标的确定和育种亲本的选配提供依据,还可以很好地了解木莲属各个种的优缺点,为建立木莲属园林植物核心种质资源库提供数据支持,也便于人们根据各自的目标进行选择。     

对"十五"期间农经工作的思考

农业经营管理工作原本是一门社会科学与自然科学相互交织的边缘科学,主要是以调查、研究农村社会经济的发生发展,为上层领域决策提供依据的一项工作.90年代后,随着农村社会经济的深化改革,以及农业和农村经济结构战略性的调整,更加繁衍和丰富了农经工作的内涵."十五"期间它将是在围绕稳定农村双重基本经营制度,搞好农村土地承包,减轻农民负担和集体财务资产三大管理的基础上,切实抓好农业产业化经营,农民专业合作经济组织和农业社会化服务体系建设这三项指导工作.也即是今后几年内,农经工作的重心应该是强化三大管理,积极探索三项指导工作.     

珍贵藏药匙叶翼首草的有效成分与药用价值研究

藏药匙叶翼首草是一种珍贵的药用植物,随着该药在各方面的应用,需要对其的药理作用和毒性作用进行进一步的研究。文章通过对藏药匙叶翼首草的化学成分、鉴别方法与药用价值进行了综述,以期为其的合理用药提供原则,为药理毒理研究提供理论依据。     

对叔丁基杯[4]芳烃Schiff碱衍生物的合成及其对铬（Ⅵ）离子的萃取性能

合成了分别含吡啶基团和N,N - 二甲基苯胺基团的2种对叔丁基杯[4]芳烃Schiff碱衍生物3a和3b.研究了这2种杯芳烃衍生物对铬(Ⅵ)离子的萃取作用,测定了水相pH值和振荡时间对萃取率的影响,结果表明化合物3b比3a对铬(Ⅵ)离子具有更好的萃取效果,探讨了萃取机理.     

间歇性干旱对苜蓿根瘤形成的影响

模拟田间土壤干湿交替及其强度,研究灌溉模式对苜蓿(Medicago sativa L.)根瘤菌有效性的影响,以及间歇性干旱对寒旱区苜蓿根瘤形成的影响。结果表明:间歇性干旱将影响苜蓿根瘤的正常发育,且周期越长,对根瘤菌的有效性影响越大;不论土壤是否缺水,根瘤均随着生长期的延长不断向侧根转移;当土壤持水量为32.7%,一次灌水达土壤持水量的80%,间歇干旱20 d、30 d和一次灌水达土壤持水量的50%,间歇干旱20 d两种水分控制模式均可保持根瘤菌较高的结瘤能力。