仔猪早期断乳料的蛋白质来源

１仔猪对蛋白质的需求和消化仔猪早期(４．５ｋｇ～１１ｋｇ)对粗蛋白的需求一般为２０%,如果以构成理想蛋白质模式来补充合成必需氨基酸,可适当降低饲粮粗蛋白质水平。这主要取决于饲料中能量水平及饲料原料的营养消化率。近年来有研究表明,断奶料中随着粗蛋白水平的提高,仔猪肠后段的腐败性物质增多,董国忠等(１９９７)报道,随着断乳料蛋白水平增高,对仔猪组织损伤程度加剧。由于早期断乳仔猪消化道尚未发育健全,各种消化酶合成分泌水平很低,且对饲粮蛋白质来源极为敏感。研究表明,不同蛋白质来源影响仔猪消化酶合成,尤其是蛋白酶(胃蛋白…     

Cloning and bioinformatics analysis of cDNA encoding cattle Smad4 gene

The cDNA of cattle Smad4 gene was cloned by RT-PCR, 3′ RACE and 5’t RACE and got a 3503-bp full-long cDNA sequence. The cloned cattle Smad4 cDNA sequence had been send to GenBank and got an accession number: DQ494856. Cattle Smad4 gene consists of 12 exons and codes 553 amino acids. Cattle Smad4 cDNA shares 99%, 96%, 95%, 91% and 91% similarity in nucleic acid sequences, and 99%, 98%, 98%, 99% and 98% similarity in amino acid sequences with sheep, pig, human, rat and mouse, respectively. Smad4 cDNA was found in the testes, pancreas, liver, small intestine, ovary, lymph, cardiac muscle, skeleton muscle and thymus gland, which indicated that Smad4 was broadly expressed in cattle. __________ Translated from Acta Veterinaria et Zootechnica Sinica, 2007, 38(4): 321–325 [译自: 畜牧兽医学报]     

特早熟抗病棉花品种辽棉44特征特性及栽培技术要点

本文主要介绍辽棉44的选育过程、生物学特性、产量、纤维品质、抗病性及栽培技术要点。     

煤矸石山立地条件与林业复垦研究——以山西统配煤矿为例

煤矸石是我国工业排弃数量最大的固体废弃物，它带来的危害是压占土地、破坏景观、污染环境。山西省作为能源重化工基地，煤矸石的堆积、污染问题尤为突出，改造任务异常艰巨。研究结果表明：煤矸石成山状堆积，仅表层１０ｃｍ左右有物理风化，下层很难风化；煤矸石山可蓄一定的水分，但地表高温，养分贫瘠，特别是自燃后的矸石强酸高盐，给植被恢复带来了极大的困难；大量煤矸石山的基本出路是进行林业复垦。其适用技术体系包括：①做好水保工程，保留地表黑色风化层；②引入先锋草种、树种；③薄盖土后直播；④加强施肥、病虫害防治等管理。     

幸福堰引水工程中的双箱式取水及输水暗涵设计

 幸福堰引水工程的建设主要服务于巧家县金塘乡部分土地灌溉和人畜饮水，在整个工程中存在着许多特殊问题需要解决，其中，取水防沙是最关键的问题之一。介绍的设计方法成功地解决了取水、防沙等问题，为泥石流地区和水土流失严重地区取水防沙工程设计提供了好的参考。     

Chemical composition and microstructure of uroliths and urinary sediment crystals associated with the feeding of high-level cottonseed meal diet to water buffalo calves

The chemical composition and microstructure of seven uroliths and four urinary sediment samples associated with the feeding of high-level cottonseed meal diet to buffalo calves were examined by chemical qualitative analyses, scanning electron microscopy ( ), X-ray diffraction, and X-ray energy dispersive spectrometry ( ). Struvite was a major component of kidney stones and of some bladder stones. The kidney stone sample appeared cracked under low power under , aggregated into tiny balls under high power, and as a bladelike structure under even higher power. The bladder stone samples appeared finely granular or granular with various forms of prismatic crystals. The urinary sediments were prismatic crystals, with granules. The newly found prismatic crystals, which were rich in potassium and similar to struvite in crystal structure, were identified as potassium magnesium phosphate (KMgPO₄ · 6H₂O) in some bladder stones and urinary sediments. However, crystals which contained Mg and P only, which had been used for struvite identification, were not found by examination in urinary sediments from fresh urine samples of buffalo calves fed the high-level cottonseed meal diet.     

集安市杜仲引种实验研究

杜仲为中国特产,全世界仅在中国有1属1种,是名贵中药材。集安市从1996年开始进行引种栽培实验研究,通过12 a的研究观察和对树干解析分析,认为杜仲引种到集安市,长势良好,各项指标达标。     

菌毒清对苹果腐烂病的毒力测定和田间治疗试验

室内测定表明,菌毒清对Valsa mali菌丝生长和分生孢子散发具有极强的抑制作用。该药剂对菌丝生长的剂量反应回归式为y=3.755+1.951x,EC_(50)为4.35ppm,EC_(95)为30.14ppm;对分生孢子萌发的剂量反应回归式为y=1.266+4.870x,EC_(50)为5.844ppm,EC_(95)为12.69ppm。在50ppm和100ppm表现抑菌作用。200ppm以上表现杀菌作用。残效期为25～30天。田间试验50～100ppm药液涂治病斑治愈率98%以上,未见复发。     

新形势下如何发展山区农业机械化

山区农业机械化受地理条件的限制和农机技术推广管理体制的制约,导致农业机械化推广进程缓慢.本文重点结合陕南汉中山区的现状,对山区农业机械化存在的问题及对策做了一些分析.     

浅谈河津市水土保持生态环境建设

河津市地处山西省西南部的吕梁山南麓,总土地面积592.3 km2,水土流失面积308 km2,占52%。截至2005年底,全市累积治理水土流失面积182.50 km2,治理度59%。由于开发建设项目较多,人为造成的新的水土流失较严重。今后的水土保持对策:一要明确思路,加强领导;二要明确方向,分区治理;三要依法管理,加强保护;四要推广科技,提高水平;五要培育大户,封禁治理。