毛用型羊品种的分类及特征

1分类根据羊毛类型分类。细毛型,如美国美利奴羊、兰布列羊等;中毛型,如南丘羊、萨福克羊等;长毛型,如罗姆尼羊等;杂交型,如北加索羊等;地毯毛型,如黑面高原羊等;羔皮用型,如卡拉库尔羊等。按照生产性能细毛羊又细分为三类,即毛用细毛羊,如中国美利奴羊等;毛肉兼用细毛羊,如新疆细毛羊等;肉毛兼用细毛羊,如德国美利奴羊等。半细毛羊又细分为二类,即毛肉兼用半细毛羊,如茨盖羊等;肉毛兼用半细毛羊,如考力代羊等。     

兰州市红古区农用地分等评价与分析

通过对土地自然质量、土地利用水平、土地经济水平逐级订正,综合评定了兰州市红古区的农用地等别。结果表明：（1）全区有24.69%的耕地为自然质量一般的5等地,15、17等自然质量高的耕地占56.84%;（2）农用地利用等共分为6个利用等别,4等地占参评耕地总面积的24.69%,而13、14等较高,占56.67%;（3）农用地的等别划分为4个,其中,2等地所占比例为24.69%,6等地所占比例最大,为56.67%。     

不同季节桑树病虫的防治对策

<正>桑树病虫因各地气候、土壤、桑园管理措施等的不同而各有不同。就病害而言,属全株性病害的有桑萎缩病,枝干病害的有桑芽枯病、桑膏药病等,根部病害的有桑紫纹羽病、桑根结线虫病等,叶部病害的有桑疫病、桑褐斑病等,桑椹病害的有桑肥大性菌核病等。虫害有桑螟、野蚕(咀食叶片)等,桑毛虫、桑尺蠖(兼食芽叶)等,桑天牛、桑蛀虫(蛀食枝干)等,以及地下害虫如蝼蛄等,这些病虫对蚕桑生产及蚕茧产质量的影响极大。笔者集多年生产实践,根     

猪等孢球虫检测及防控研究进展

猪等孢球虫是一种危害仔猪生长的专性寄生性原虫,感染该寄生虫的仔猪生长缓慢,且常表现出腹泻症状,甚至死亡,对养猪业造成极大危害。本文综合了国内外研究成果,从流行病学特征、形态特征、生活史、检测方法及防控措施等方面对仔猪等孢球虫进行了综述,并对猪等孢球虫的防控手段、内生发育史、基因组学等生物学特性以及与肠道菌群的相互作用等问题进行了展望,以期为猪等孢球虫的病原鉴定及有效防控提供科学依据。     

高层建筑等电位联结安装技术分析探讨

随着社会经济的不断发展以及城市化进程的不断加快,高层建筑犹如雨后春笋般崛起,然而建筑越高,等电位连接安装越是复杂,也就会相应的存在火灾隐患.本文首先详细介绍了等电位联结安装的主要原理,然后将总等电位、辅助等电位、局部等电位三个方面的联结来对高层建筑等电位联结的安装技术进行深入分析与探讨,从而保证居民能够安全用电.     

血浆蛋白粉对仔猪的作用机理研究进展

<正>早期隔离断奶(Segregated early-weaning,SEW)可以防止疫病垂直传染,提高仔猪生产性能和母猪繁殖效率,降低生产成本。但早期断奶仔猪的消化系统发育不完善,消化酶含量少且活力低,自身免疫系统尚未发育完全,不能有效利用日粮中复杂多糖和植物蛋白(Hansen等,1993;Cranwell,1995;Grinstead等,2000),加上遭遇心理、营养、环境等因素的断奶应激(Pluske等,1997),会引起肠道炎症和机体促炎反应(McCracken等,1999;Jiang等,2000)。     

兽医药理知识系列讲座（六）——特异性解毒药的分类及临床应用

解毒药是一类能直接对抗毒物或解除毒物所致毒性反应的药物。根据其作用特点,可分为非特异性和特异性两类,前者主要指催吐剂（硫酸铜等）、吸附药（活性炭等）、沉淀药（糅酸等）、保护药（淀粉浆等）、导泻剂（硫酸钠等）及利尿剂（氢氯噻嗪等）,通过防止毒物进一步吸收或促进其排出体外来减轻多种毒物的中毒.     

牧草的种植、利用及加工

1品种选择 根据饲养的畜禽品种来选择牧草的种植种类.牛羊是反刍动物,具有较强的消化粗纤维的能力,应选择粗纤维含量较高的品种,以禾本科牧草为主,合理搭配豆科牧草,如玉米、高梁、杂交苏丹草、紫花苜蓿、沙打旺等.兔子是小型草食动物可以利用多种牧草,在种植时应选择稗子等叶片比较大的禾本科为主的品种,为增加牧草蛋白质含量应配合相应的苜蓿等豆科牧草.猪可以利用部分优质牧草,如大麦、燕麦等.鹅应该选择多叶类禾本科、苜蓿等豆科以及籽粒苋等苋科、菊苣等菊科多汁类品种.     

三种免疫增强剂的研究进展

免疫增强剂是指单独或同时与抗原使用时能增强机体免疫应答的物质。免疫增强剂的研究涉及免疫学和药学的内容,是近几年应用医学最活跃的研究领域之一。免疫增强剂的种类繁多,不下十几类上百种,包括矿物质类,如硒、锌等;中草药类,如黄芪、白芍、芦荟、当归等;免疫佐剂类,如蜂胶、弗氏佐剂等;微生物制剂类,如卡介苗、霍乱毒素B亚单位等;维生素类,如维生素A、维生素E等;氨基酸类,如精氨酸、亮氨酸等;激素或激素样物质类,如生长激素、胸腺肽等;     

种草养畜七要点

1按用途分类种植牧草的种类很多,分禾本科牧草、豆科牧草、菊科牧草、蓼科牧草、苋科牧草等,用途很广,可以喂牛、羊、兔、鸡、鸭、鹅等。种草应根据饲养的畜禽品种而定,做到以养定种,以种促养。牛、羊喜食禾本科牧草,如墨西哥玉米、冬牧70黑麦草、苏丹草、早熟禾等,其次是豆科牧草,如紫花苜蓿、三叶草、沙达旺等。猪、禽喜食菊科多汁牧草,如串叶松香草、菊芋、菊苣、苦荬菜等,其次是豆科牧草,如紫花苜蓿、三叶草、小冠花等。兔、鹅喜食豆科牧草,如紫花苜蓿、三叶草、小冠花等,其次是禾本科牧草,如冬牧70黑麦草、苏丹草等。为了做到常年喂青,…     

俄罗斯优质牧草品种引种筛选试验初报

对从俄罗斯引入的49个牧草品种进行试种筛选试验.通过2年试验初步认为适于当地的高产优质豆科牧草品种为02-29紫花苜蓿Medicago sativa,禾本科牧草品种为02-27无芒雀麦Bromus inennis;适于岗坡瘠薄土壤的禾本科牧草品种为02-14披碱草Elymus dahuricus;适于低湿易涝地的禾本科牧草品种为02-23草芦Phalaris arudinacea;适于饲喂猪、鹅等家畜的多汁、高产一年生牧草品种为02-47欧洲菘蓝Isatis indigotica.     

Evaluation of bovine embryos produced in high performance serum-free media

This review evaluates the quality of bovine embryos developed from in vitro-matured (IVM) and -fertilized (IVF) oocytes cultured in either serum-free or serum-containing media. Bovine embryos cultured in serum-supplemented medium contain numerous cytoplasmic lipid droplets and immature mitochondria compared to those cultured in serum-free medium. The accumulation of cytoplasmic lipids in embryos developed in serum-containing medium may be a result of incorporation of lipoproteins from the serum and may result in impaired function of mitochondria. The improved serum-free media (IVMD101 and IVD101) offer several advantages over culture in serum-containing medium, including increased rates of blastocyst formation and higher cell numbers. Additionally, the survival and hatching rates of embryos produced in serum-free media after post-thaw culture were superior to those of embryos produced in the serum-containing medium, suggesting that the abnormal accumulation of cytoplasmic lipids in embryos may have a negative effect on the sensitivity of embryos to chilling and freezing. These serum-free culture systems have proven to be beneficial for the production of good quality embryos from IVM-IVF bovine oocytes. Furthermore, recent studies have shown a correlation between mitochondrial function (oxygen consumption) and embryo quality. A new method using scanning electrochemical microscopy may be capable of assessing the viability and developmental potential of bovine embryos.     

安顺金刺梨生长特性及高产优质栽培技术

通过对安顺金刺梨物候期、枝梢生长、果实性状的特性观察，同时开展高产优质栽培技术研究，结果表明：安顺金刺梨1月上中旬开始春梢萌动，一年可抽生3次梢，即春、夏、秋梢。春梢抽生后即进入快速生长阶段，在5月底短暂停止生长；6月初开始大量抽生夏梢，多为二次梢；8月中旬开始抽生夏梢。4月下旬开花，花期可持续一个月。成熟果实坛形或椭圆形，果型端正，果面橙黄色，果实金黄色，果皮具小肉刺，果肉脆、风味酸甜可口，成熟后有浓芳香味。果实内富含超氧化物歧化酶（SOD）（3869U/g），含可溶性固形物22%，果实硬，耐贮运，植株健壮，生长势好，抗病性强，平地、田块、25度以下坡地均可栽培。     

高铁高硒日粮对鸡蛋品质的影响

用高铁高硒日粮饲喂产蛋母鸡,观察蛋品质的变化,结果表明,蛋黄重、蛋黄重／蛋重比略有下降,蛋白质／蛋重比、哈夫单位有所提高,蛋壳／蛋重比,蛋壳厚度及蛋壳密度无明显变化,提示：高铁高硒日粮不会引起蛋品质的明显下降。     

Influence of corpus luteum and ovarian volume on the number and quality of bovine oocytes

In order to evaluate whether ovarian volume, presence and diameter of the corpus luteum (CL) have effects on the number and quality of bovine recovered oocytes, 110 ovaries were obtained from the slaughterhouse. Cumulus oocytes complex were aspirated and evaluated under stereomicroscope. Oocytes were counted and classified according to their quality (Grades I, II, III and IV). Ovarian volume was weakly correlated to the number of good quality oocytes (P < 0.05). Ovaries with CL showed greater numbers of good quality oocytes than ovaries without CL (P < 0.05). Further, presence of CL and its diameter positively influenced the probability of recovering good quality oocytes (P < 0.05). In conclusion, ovarian volume is not a good parameter itself to predict important ovarian characteristics; moreover, analysis of CL, its presence and diameter, may be a good tool to improve efficiency on in vitro embryo production programs.     

桑树良种化与蚕业发展

桑树品种是蚕业生产的物质基础。优良桑树品种的推广应用对提高桑叶产量、改善桑叶品质、增强桑树对不良环境的抵抗性 ,进而对增加蚕茧产量 ,提高茧质、种质、丝质都有重要的作用。为了蚕业生产的持续稳定发展 ,加快我国桑树良种化进程 ,促进蚕桑生产朝“两高一优”农业发展 ,是一项重要任务     

Seasonal Effect on Zebu Embryo Quality as Determined by Their Degree of Apoptosis and Resistance to Cryopreservation

In order to optimize the production of embryos under tropical conditions and to test a possible seasonal effect on embryo quality, 40 Zebu cows were superovulated during the dry season (April to May) and during the rainy season (July to August). A total of 116 (average 2.7/cow) and 83 embryos (3.5 average/cow) were obtained during the respective seasons. After classification as good, fair or poor quality, embryos were tested based on their ultrastructural differences (n = 53 dry season 16 good, 20 fair and 17 poor and n = 61 rainy season 21 good, 20 fair and 20 poor) and their degree of apoptosis using the TUNEL technique (n = 30 during the dry season and n = 55 in the rainy season). Structural characteristics determining embryo quality varied between good and fair quality embryos. No difference, however, was observed between good, fair and poor quality embryos from the two seasons. The number of TUNEL-positive cells was different among embryos (p < 0.001), being lower in labelled cells of good quality embryos regardless of the season. Fewer apoptotic cells were observed in embryos assigned in all three quality levels during the rainy season (p < 0.001). Ultrastructural evaluations confirmed the results obtained by TUNEL. Cryopreserved embryos of good (n = 25 in each season) and fair quality (n = 11 dry season; n = 17 rainy season) showed a significant decrease of TUNEL-positive cells during the rainy season (p < 0.05). Results suggest that embryos collected in the dry season have more cellular damage in contrast; embryos cryopreserved in the rainy season appeared morphologically better equipped to result in a pregnancy following transfer.     

Comparison of carcass and meat characteristics of Brahman grade cattle (Bos indicus) and crossbred water buffalo (Bubalus bubalis) fed on high roughage diet

The objective of this study was to compare the carcass and meat quality in crossbred cattle and crossbred water buffalo at the same younger age and fed with high roughage in the Philippines. Ten crossbred cattle and 10 crossbred water buffalo, with an average age of 22 months (18–24 months) were used in this experiment. The animals were fed a similar diet, which consisted of 85% Napier or Para grass and 15% concentrate mixture on a dry matter basis, for 180 days before slaughter. Slaughter weight of the crossbred water buffalo was higher (P < 0.05) than that of the cattle, although the dressing percentage was significantly (P < 0.01) lower for the former than for the latter. The estimated lean yield was higher (P < 0.05) in crossbred cattle than crossbred water buffalo. The muscle fiber diameter of loin in buffalo meat was smaller (P < 0.05) than that in cattle. In regard to carcass and meat quality, the crossbred water buffalo was comparable or slightly superior to the crossbred cattle in tenderness, sensory score of color (P < 0.01) and flavor (P < 0.05). These results clearly indicate that at a younger age and even under high roughage‐based fattening rations, crossbred water buffalo are able to produce good quality meat, which will be by no means inferior to that of crossbred cattle in the Philippines.     

优质饲草鲁梅克斯的加工与合理利用

本文就优质饲草鲁梅克斯的形态特征、生长发育特点、营养特点、各种加工调制技术及各类畜禽的饲喂技术和饲喂效果进行了综述。     

龙安柚高品质果品培育技术

龙安柚是四川广安选育的地方柚良种，具有红肉、无核、品质优等特点，目前在广安已大面积推广，但在生产发展中出现了品质和产量不稳定等问题，本文总结了培育高品质龙安柚果品的一些技术经验，主要包括搞好病虫防治，重施有机壮果肥，保持树冠适度通风透光，花果管理，进行果实套袋，在果实充实期遇绵雨时进行地面铺膜，保持土壤适度干燥等措施。措施使龙安柚果品质量、产量和安全都得到较好提高。