首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
通过雏鸡人工感染鸡蛔虫和异刺线虫的试验证明,鸡蛔虫、异刺线虫单独或混合感染,对雏鸡的成活率及发育均有程度不同的影响。与不感染对照组相比,感染300个/只蛔虫卵的雏鸡成活率低19%(P<0.05),死亡峰期在感染后7~14天,增重低30.1%(P<0.01),影响增重峰期为感染后第1~10和21~40天;感染同量异刺线虫卵雏鸡成活率低10.3%(P>0.05),死亡主因是组织滴虫病,增重低16.6%(P<0.05),影响增重峰期在感染后第11~20天,混合感染减半量的两种虫卵,成活率低14%(P<0.05),增重低32.9%(P<0.01),死亡及发育受阻期与单独感染蛔虫卵组相似,但部分鸡死于组织滴虫病;单独感染减半量蛔虫卵,成活率低17.3%(P<0.05),增重低10.1%(P>0.05),死亡及影响增重峰期基本在感染后第1~10天。  相似文献   

2.
The Cornell Net Carbohydrate and Protein System (CNCPS) has a submodel that predicts rates of feedstuff degradation in the rumen, the passage of undegraded feed to the lower gut, and the amount of ME and protein that is available to the animal. In the CNCPS, structural carbohydrate (SC) and nonstructural carbohydrate (NSC) are estimated from sequential NDF analyses of the feed. Data from the literature are used to predict fractional rates of SC and NSC degradation. Crude protein is partitioned into five fractions. Fraction A is NPN, which is trichloroacetic (TCA) acid-soluble N. Unavailable or protein bound to cell wall (Fraction C) is derived from acid detergent insoluble nitrogen (ADIP), and slowly degraded true protein (Fraction B3) is neutral detergent insoluble nitrogen (NDIP) minus Fraction C. Rapidly degraded true protein (Fraction B1) is TCA-precipitable protein from the buffer-soluble protein minus NPN. True protein with an intermediate degradation rate (Fraction B2) is the remaining N. Protein degradation rates are estimated by an in vitro procedure that uses Streptomyces griseus protease, and a curve-peeling technique is used to identify rates for each fraction. The amount of carbohydrate or N that is digested in the rumen is determined by the relative rates of degradation and passage. Ruminal passage rates are a function of DMI, particle size, bulk density, and the type of feed that is consumed (e.g., forage vs cereal grain).  相似文献   

3.
猪圆环病毒(PCV)分为1型(PCV-1)和2型(PCV-2).PCV-1一般认为无致病性,而PCV-2是断奶仔猪多系统衰竭综合征(PWMS)的主要致病因子;此外,猪皮炎肾病综合征(PDNS)、仔猪先天性震颤(CT)等疾病也与PCV-2有关.在临床上PCV-2常与猪繁殖与呼吸综合征病毒(PRRSV)、猪细小病毒(PPV)、猪流感病毒(SIV)等病毒混合感染,PCV-2相关疾病已经给世界养猪业造成了巨大的经济损失.然而,由于该病常常和上述几种疾病混合感染,且其临床症状十分类似,所以仅仅依靠单一的临床症状或者某一种实验室诊断方法并不能有效的检测该病.因此,将目前诊断PCV-2的各种方法集中起来,分析其优缺点,从而可以根据实验室的具体情况采取合适的方法是诊断该病的关键.论文就目前PCV-2的检测技术做一介绍.  相似文献   

4.
放牧强度和时期对内蒙古草原土壤压实效应的研究   总被引:27,自引:6,他引:27  
贾树海  李绍良 《草地学报》1999,7(3):217-222
在不同牧压下,测定土壤容重,硬度,孔隙度,毛管持水量等与土壤压实作用的有关物理指标。结果表明,供试放牧强度对土壤容重的影响仅局限于0-10cm,其中以0-5cm最显著。0-10cm土壤容重的为y=1.236+0.595x-7.764*10^-3x^2,R=0.978。相同放牧强度不同放牧时期对土壤容重的表现丰夏季放牧对于土壤的压实作用最轻,秋季最重,春季居中。  相似文献   

5.
死亡结构域蛋白(FADD)是在生物细胞里起到信号转导作用的一种蛋白,在胚胎发育、细胞凋亡过程中发挥重要的生物学活性。实验以成年母牦牛的卵巢RNA为模板,利用RT-PCR技术克隆牦牛FADD基因,并进行了生物信息学分析。结果表明:牦牛FADD基因CDS区长度630 bp,编码209个氨基酸,蛋白分子式C996H1632N300O307S7,整个蛋白质带负电荷,总共原子数量3 242;分子质量23.0 ku,半衰期30 h;理论等电点6.11;消光系数18 240;不稳定指数49.08,属于不稳定蛋白;脂肪系数104.64,平均亲水系数-0.168,预测FADD蛋白为亲水蛋白。系统进化树表明,牦牛与哺乳动物亲缘关系近,与鱼亲缘关系最远,符合物种进化规律。FADD蛋白质的二级结构α螺旋、自由卷曲、β-转角和延伸链,占靶蛋白的比例分别为71.29%、22.97%、3.83%和1.91%,与三级结构相符。牦牛FADD蛋白有13.0%位于细胞核、52.2%位于细胞质、8.7%位于细胞外、13.0%位于线粒体、4.3%位于高尔基体和8.7%位于细胞骨架。该研究成功克隆出牦牛FADD基因CDS区,为进一步研究其功能提供了一定理论依据。  相似文献   

6.
本试验用壮观霉素,通过控制试验和临床治疗对人工感染和自然感染猪支原体肺炎的病猪进行治疗试验。控制试验分三种不同剂组,治疗1个疗程。10毫克/千克体重的治愈率为75%,治疗有效率为100%。20毫克/千克体重和30毫克/千克体重的治愈率均为91.7%,治疗有效率为100%。  相似文献   

7.
快速与慢速肉鸡脂肪生长与肌苷酸含量比较   总被引:23,自引:0,他引:23  
本试验旨在相同条件下,比不同品种和性别肉鸡的脂肪生长量和肌苷酸含量及其相互关系。比较发现:(1)快速与慢速肉鸡的各项脂肪指标均无显著差异(p>0.05),但慢速鸡的肌肉脂肪、皮下脂肪和腹脂率分别比快速鸡高7%、13%和37%;(2)慢速肉鸡肌苷酸含量比快速高50%,且差异显著(p<0.05);(3)母鸡皮下脂肪(p<0.01)和腹脂率(p<0.05)显著高于公鸡,母鸡肌间和肌肉脂肪也分别高于公鸡6%和12%(p>0.05);(4)肌苷酸与腹脂率存在显著正相关(r=0.61,p<0.05)。  相似文献   

8.
The future of veterinary parasitology   总被引:2,自引:0,他引:2  
Current evidence suggests research in veterinary parasitology is in decline despite its importance. This is particularly true in the UK where research funds have been diverted into BSE. Decline in interest in veterinary parasitology is at least in part due to the success of major pharmaceutical companies in producing a range of effective and safe anti-parasitic drugs. Research is needed because of the effects of parasites on animal welfare and the economic costs of parasites. However, there is little information on the actual costs of animal parasites. Another major reason for research is the development of drug resistance in protozoa, helminths and arthropods of veterinary importance. This is a serious problem particularly for sheep and goats in the southern hemisphere. A prioritised list of research requirements is suggested: (i) new drugs; (ii) resistance management; (iii) vaccines; (iv) breeding for resistance; (v) improved diagnostics; (vi) zoonoses; (vii) global warming and parasites. There is a major political challenge to raise the profile of veterinary parasitology and thus the funding essential for its advancement and the continued welfare and productivity of animals.  相似文献   

9.
试验利用PCR-RFLP法研究了三江白猪OB基因3 469位点的多态性及其与繁殖性能的相关性。结果表明:OB基因经HinfⅠ酶切后出现3个条带,表现为3种基因型(AA型、AB型和BB型)和2个等位基因(A和B),A等位基因为优势基因,基因频率为67.6%;头胎产活仔数BB型极显著高于AA型(P<0.01),BB型高于AB型,AB型高于AA型,但差异都不显著(P>0.05),BB基因型比AB型和AA型的头胎产活仔数分别高出1.65头、2.19头;不同的基因型对前5胎最高产仔数的影响差异不显著(P>0.05)。  相似文献   

10.
黎平黄牛体重估测公式探讨   总被引:3,自引:0,他引:3  
随机实测261头黎平黄牛的胸围,体斜长和体重,根据体重等于体积乘以密度(比重)的原则,采用回则分析方法进行了黎平黄牛体重估测公式的推导与验证。结果表明,黎平黄牛的性别对体尺与体重回归关系的影响差异不显著(P〉0.05),合并公母牛的体尺体重数据。得出该品种总的体重估测公式;体重(kg)=胸围^2(m)×体斜长(m)×88-8(r=0.9971,Sy/x=4.701)胸围,体斜长对体重的回归关系极显  相似文献   

11.
12.
邱翔  王晋峰 《四川草原》2005,(12):27-31,44
以西南民族大学南门侧草坪为研究对象,分析了草地早熟禾、多年生黑麦草、天胡荽、繁缕、蛇莓等 5个代表性物种的种间相遇机率(PIE)及密度(D)、盖度(C)、频度(F)的相关性。结果表明:当物种密度大时,株丛个体大小与盖度呈正相关,株丛呈随机分布则频度较大,株丛呈群聚分布则频度不一定高。而盖度大时, 频度大小亦与株丛分布的均匀度有关。据PIE分析,以蛇莓和草地早熟禾最大,其次为风轮草,再次为天胡荽、白三叶,最小的为甘油菜,符合实际分布状况。  相似文献   

13.
高寒草甸“黑土型”退化草地的成因及生态过程   总被引:46,自引:3,他引:46  
刘伟  李有福 《草地学报》1999,7(4):300-307
研究分析退化草地的植被组成、地上生物量、优良牧草比例、高原鼠免密度以及土经性质等特征,探讨“黑土型”退化草地的成因及生态过程。结果透明,中度退化草地生物量最高950.3g/0.25m^2)。原生植被优良牧草比例最高(78.40%)。重度退化草地最低(4.49%),轻度和中度退化草地居中(57.2%和16.42%)。中度退化草地高原鼠兔平均密度较高(148只/hm^2),二者之间呈显著的正相关(r=  相似文献   

14.
本研究选择甘肃皇城羊场成年甘肃高山细毛羊母羊200只,随机分成两组,试验组穿上特制的绵羊罩衣,对照组不作任何处理,相同条件下饲养管理到第二年春季测定羊毛品质指标。结果表明,试验组平均羊毛长度比对照组长0.29 cm,差异显著(P<0.05);羊毛细度试验组与对照组相差仅0.7μm,差异不显著(P>0.05);羊毛油汗长度试验组比对照组长2.76cm,差异极显著(P<0.01);毛丛污染深度,试验组比对照组污染深度短2.46 cm,差异极显著(P<0.01);羊毛脂和汗质的含量试验组比对照组分别提高55%和16.5%,差异均极显著(P<0.01);羊毛中杂质含量对照组杂质含量比试验组高20.47个百分点,差异极显著(P<0.01);毛束强度试验组仅比对照组毛束强度偏低2.22N/kt(P>0.05)。  相似文献   

15.
家蚕第2隐性赤蚁的遗传学研究——Ⅱ.ch-2基因的连锁分析   总被引:1,自引:1,他引:0  
Ch-2基因是继ch之后新发现的一种隐性赤蚁ch-2基因与pM(2)、Ze(3)、L(4)、Pe(5)、E~(EL)(6)、q(7)、st(8)、I(9)、w-2(10)、ms(12)、cf(13)、U(14)、Se(15)、cts(16)、B_m(17)、nb(19)、rb(21)、or(22)、sp(23)、Nd(25)、及Y_m等各标志基因都是独立遗传.Ch-2与mln杂交F_2代分离+ch-2+min:ch-2+min:ch-2mln:ch-2mln=523:284:231:0≈2:1:1:0;ch-2与elp杂交F_2代分离+ch-2+elf:ch-2+elp:+ch-2elp:ch-2elp=219:97:68:0≈2:1:1:0,充分说明ch-2与mln、elp是连锁遗传的,即ch-2基因位于第18连锁群.  相似文献   

16.
The main aim of this article is to identify those factors that affect treatment compliance, the extent to which the owners of patients comply with the treatment regimen, and how to improve compliance. The article is mainly based on reports from the medical literature. Although compliance can be measured in several ways, there is no valid and reliable method. For this reason, several methods should be used. Factors that affect treatment compliance in human medicine are (I) the expected effectiveness of treatment, (II) the severity of the disorder, (III) the risks associated with medicine use, (IV) the duration and dosage of medical therapy, (V) patient motivation, and (VI) the doctor-patient relationship. In the literature, in veterinary medicine treatment compliance is reported to range from 44% to 55%, whereas in human medicine it is reported to range from 5% to 96%. Compliance can be improved if (I) the owner can easily incorporate the treatment regimen in his/her daily life, (II) the treatment regimen does not disrupt the owner's daily routine, (III) the owner is informed about and understands the treatment provided, and (IV) the relationship between veterinarian and owner is good. In conclusion, many questions about treatment compliance in veterinary medicine remain unanswered, and research is needed to answer them.  相似文献   

17.
哈萨克牛四种蛋白多态与体尺性状关系的分析   总被引:1,自引:0,他引:1  
哈萨克牛 Tf、Ptf、Alb和 Pa等 4个蛋白位点分别有 4、2、2和 3种表型 ,分别受 3、2、2和 2个共显性等位基因支配。应用最小二乘法拟合线性模型 ,研究 4个蛋白位点的基因型与哈萨克牛体尺性状间的关系 ,结果表明 ,在胸深性状上 ,Tf AE型的 LSE值显著高于 Tf DE型的 LSE值 ( P<0 .0 5 ) ;在胸围性状上 ,Tf AE型的 LSE值极显著高于 Tf DE型的 LSE值 ( P<0 .0 1 ) :对于胸深性状 ,Ptf AA型的LSE值显著高于 Ptf AB型的 LSE值 ( P<0 .0 5 ) ;在腰角宽性状上 ,Alb AA型的 LSE值显著高于 Alb AB型的 LSE值 ( P<0 .0 5 ) ;对于臀端高性状 ,Pa AA型的 LSE值极显著高于 Pa AB型的 LSE值 ( P<0 .0 1 ) ;对于十字部高性状 ,Pa AA型的 LSE值显著高于 Pa AB型的 LSE值 ( P<0 .0 5 )  相似文献   

18.
为探索互助八眉三元商品猪育肥前期饲料配方,在消化能水平为13MJ/kg前提下,日粮粗蛋白水平分别为14%(1#)、16%(2#)、18%(3#)三个试验组.结果表明:3#日增重与各试验组之间差异不显著,与对照组之间差异显著(P<0.05);料重比最小,与各组之间差异极显著(P <0.01);单位增重饲料成本最低,与2#...  相似文献   

19.
几种江西地方品种鹅肌肉化学成分测定分析   总被引:6,自引:2,他引:4  
为探索江西地方品种鹅肉嫩味美的机理,比较不同鹅品种肌肉成分的特点,对120日龄的4种江西地方品种鹅:莲花白鹅、广丰白银鹅、兴国灰鹅、丰城灰鹅进行肌肉常规化学成分及脂肪酸测定比较,结果表明,蛋白质、灰分及水分3项指标在品种间达极显著水平(P<0.01),其中水分含量以莲花白鹅最高达73.389%,兴国灰鹅最低为69.473%;蛋白质和灰分含量以兴国灰鹅最高,分别为24.379%和1.462%,丰城灰鹅最低,分别为21.604%和1.290%;脂肪含量以兴国灰鹅最高,但各品种间差异不显著,不饱和脂肪酸的含量也以兴国灰鹅最高。  相似文献   

20.
The claimed low production of CH(4) by kangaroos and marsupials in general has been questioned because of a lack of data. The extent of their CH(4) production is of interest both from the point of view of discussing meat production of marsupials and as a basis for developing methods to reduce CH(4) production from ruminants. In the present experiment, the CH(4) production of 8 red-necked wallabies (Macropus rufogriseus) was measured of which 4 were fed 2 different diets in an open-circuit respiration chamber. These results were compared with a newly developed, inexpensive, and simple method that does not influence the behavior of the animal, and where the ratio between CH(4) and CO(2) is measured and used together with the calculated CO(2) to quantify the CH(4) production. The experiment demonstrated that the wallabies produce CH(4). However, the amount of CH(4) produced by these wallabies was between 1.6 and 2.5 L/d equivalent to 1.6 and 2.5% of GE or 2.2% and 3.5% of DE intake and 0.22 L/BW, kg(0.75). This is between 25 and 33% of what can be expected from ruminants fed the same diet. Based on the uneven release of CH(4) with time, it is most likely that the CH(4) is excreted through flatulence and not through breathing as is seen in ruminants. The experiments also showed that a reasonably accurate determination of the CH(4) production of a group of animals can be obtained by simply measuring the CH(4)/CO(2) ratio over a limited time span. This may represent the situation in a natural setting better than measurements in a respiration chamber. It was found that the CH(4)/CO(2) ratio in itself represents a reasonable prediction of the proportion of feed GE that is lost as CH(4), and that this method offers new opportunities for CH(4) measurements on a large number of animals.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号