摄入水平和苜蓿替代禾本科干草对肉牛纤维消化瘤胃动力学和颗粒通过的影响     

Bhatti S A Bowman J G P Firkins J L Grove A V Hunt C W 《饲料博览》2008,(3):65-66

两个试验旨在评价肉牛日粮中紫花苜蓿替代禾本科干草的消化动力学。试验1：要测试的饲草组合分别为：100%大须芒草,25%苜蓿和75%大须芒草,50%苜蓿和50%大须芒草,100%苜蓿。采用非线性回归测定即刻可溶性分数A,潜在的可降解分数B,不降解分数C,干物质和中性洗剂纤维消失率。随着苜蓿添加量的增加,干物质分数A线性升高（P=0.03）,干物质和中性洗剂纤维分数B线性降低（P=0.01）,干物质和中性洗剂纤维消失率线性升高（P≤0.02）。试验2：采用2×2因子设计,测试苜蓿替代鸭茅干草和采食水平的影响。苜蓿添加水平为不添加或含25%（作为饲喂基础）,采食水平为每天限制在体重的1%（以干物质为基础）或自由采食。限饲组肉牛营养素摄入量最低（P≤0.05）,自由采食鸭茅干草的肉牛营养素摄入量居中,自由采食鸭茅干草和苜蓿的肉牛营养素摄入量最高。采食水平和饲草来源对除蛋白质外的所有营养素的总消化道表观消化率没有影响（P≥0.23）。与单独饲喂鸭茅饲草的肉牛相比,采食鸭茅干草和苜蓿的肉牛蛋白质总消化道表观消化率显著提高33%（P=0.01）。干物质和中性洗剂纤维消失的延迟时间不受苜蓿或采食水平影响（P≥0.20）。限制日粮组和自由采食组,与单独采食鸭茅饲草的肉牛相比,采食鸭茅饲草和苜蓿的肉牛对鸭茅饲草干物质和中性洗剂纤维的消失率更快（P≤0.01）。与限饲组肉牛相比,自由采食组肉牛对鸭茅饲草大、小颗粒的平均贮留时间有缩短的趋势（P≤0.06）。在自由采食和添加苜蓿的条件下,小颗粒鸭茅饲草通过率趋向于更快（P=0.09）。自由采食与鸭茅饲草平均贮留时间缩短和小颗粒鸭茅饲草通过率加快相关;然而添加苜蓿能提高小颗粒鸭茅饲草通过率,干物质和中性洗剂纤维消失率。  相似文献   

中间偃麦草、长穗偃麦草及其杂种F1代同工酶研究   总被引：1，自引：0，他引：1  

撒多文  米福贵  刘玉良 《草地学报》2009,17(3):349-353

通过对过氧化物酶(POD)、酯酶(EST)、超氧化物歧化酶(SOD)和多酚氧化酶(PPO)同工酶谱的分析,探讨中间偃麦草(Elytrigia elongata(Host)Nevski)、长穗偃麦草(E.intermedia(Host)Nevski)及其杂种F₁代的酶谱特征和亲缘关系。结果表明:亲本同工酶酶带数目、迁移率、着色程度等差异不大,二者亲缘关系较近。与亲本相比,杂种F₁代存在POD、SOD、PPO酶带丢失现象,但正、反交植株中均产生了一些亲本没有的新生带。杂种F₁代EST酶谱与亲本基本相同,仅着色程度略有差异。杂种F₁代植株的POD、PPO酶谱特征有偏向中间偃麦草的倾向,而SOD酶谱特征倾向于长穗偃麦草。杂种F₁代同工酶具有多态性,可作为遗传标记用于杂种鉴定和后代株系目标性状的选择。  相似文献   

中国苜蓿审定登记品种叶形态特征及变异分析   总被引：2，自引：0，他引：2  

徐春波  于林清  王勇  萨仁 《草地学报》2007,15(3):243-247,268

利用CI-202型叶面积仪研究29个我国审定登记苜蓿品种(Medicago sativa L.)的叶长、叶宽、叶面积、叶周长、叶长/叶宽和叶形指数。结果表明:地方苜蓿品种和育成品种在叶形态方面存在着较大的差异,前者的叶片较后者小;二者叶片形状相似;在6个指标中,叶长宽比变异最大,叶周长变异最小;地方品种的叶面积、叶长、叶周长和叶长宽比的变异系数均高于育成品种,其他2项指标则低于后者;在育成品种中,中兰1号的变异最大,甘农3号苜蓿最小;在地方品种中,蔚县苜蓿的变异最大,河西苜蓿最小;该结果将为今后培育苜蓿新品种提供理论基础。  相似文献   

羊免疫布鲁菌病疫苗(S2株)免疫抗体长期监测结果的试验     

苏胜杰  马立峰  戴晓光  申捷  萨茹拉  郭少平  赵心力 《中国兽医杂志》2019,(3):29-32

为探究羊经布鲁菌病疫苗(S2株)免疫后的血清抗体长期动态消长规律,本试验于2012年9月-2015年9月选取阿拉善盟阿拉善左旗96只山羊、100只绵羊作为试验动物,经布鲁菌疫苗(S2株)100亿CFU、200亿CFU不同免疫剂量灌服,分别于免疫前和免疫后不同时间段采血分离血清,应用虎红平板凝集试验和试管凝集试验进行抗体监测。结果表明,绵羊组在一免后20d时,血清抗体阳性率达到最高峰,之后呈下降趋势,150d抗体阳性率降至0%,免疫后180d^360d,绵羊组抗体阳性率一直处于较低水平(0%~4%),二免和三免后不同时间段免疫抗体消长规律与首次免疫基本一致;山羊组抗体阳性率在免疫后20 d时,血清抗体阳性率达到最高峰,之后呈下降趋势,免疫后90 d^360 d,免疫抗体时高时低,起伏较大,无明显规律,二免和三免后不同时间段免疫抗体消长规律与首次免疫基本一致,结果同时表明,100亿CFU和200亿CFU两个免疫剂量组的抗体阳性率无明显差异。  相似文献   

白足蚜小蜂对桃蚜的取食和寄生功能反应及搜寻效应     

赵艳丽  韩丽  田秀峰  刘青娴  萨出拉  段立清 《中国森林病虫》2022,41(1):27-32

为评估白足蚜小蜂Aphelinus albipodus对桃蚜Myzus persicae的防控效果,在室内测定了白足蚜小蜂对不同发育阶段桃蚜的功能反应和搜寻效应,并对种内干扰和分摊竞争强度进行了比较。结果表明:白足蚜小蜂对不同发育阶段桃蚜的取食量和寄生量均随着蚜虫密度增加而增加,取食量和寄生功能反应均符合HollingⅡ模型。白足蚜小蜂对桃蚜的理论最大取食量2.809头,瞬时攻击率0.218,处理时间0.023 d;白足蚜小蜂对3～4日龄桃蚜寄生量最大,为47.62头,寄生瞬时攻击率0.723,处理时间0.021 d。搜寻效应均随蚜虫密度的增加而下降,且与蚜虫密度呈负相关。白足蚜小蜂个体之间存在种内干扰作用,随着自身密度增加,单头寄生率相对下降,分摊竞争强度增大,干扰效应符合Hassell-varley模型。由功能反应、种内干扰等指标可见白足蚜小蜂对桃蚜具有较好的防控作用。  相似文献   

Suspected capture myopathy in an alpaca (Vicugna pacos) following a dog attack     

SA Biasutti 《New Zealand veterinary journal》2019,67(1):52-54

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陕北毛乌素沙地仁用杏丰产栽培技术体系   总被引：6，自引：2，他引：4  

撒文清  魏安智  杨途熙  张睿  杨恒 《经济林研究》2003,21(1):47-49

针对陕北毛乌素沙地地势较为平埋，光热资源丰富，水资源相对充足，但干旱少雨，降水集中，蒸发量大，风沙危害频繁，土质疏松、漏肥、漏水现象严重等特殊的自然条件，提出了适宜该地区采用的仁用杏丰产栽培技术体系。  相似文献   

A survey of Western Australian dogs for Sarcocystis spp and other intestinal parasites     

G SA VINI  JD DUNSMORE  ID ROBERTSON 《Australian veterinary journal》1993,70(7):275-276

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Timing of oviposition in mixed systems using bright light, dim light and darkness     

B M Bhatti  A A Mian  T R Morris 《British poultry science》1988,29(2):395-401

1. Two experiments were conducted to examine time of oviposition for hens exposed to continuous dim lighting, to dim lighting alternating with bright lighting in a 24 h cycle or to a mixed system using bright light, dim light and darkness. 2. Under continuous dim lighting (0.3 lux), the pattern of ovipositions was the same as that reported previously for constant darkness, more eggs being laid around midnight than around noon. 3. With alternating bright and dim phases, mean time of lay was approximately 16 h after the transition from bright to dim lighting, which was 3 h earlier than under the corresponding cycle of light and dark. This phase advance was the same whether the bright:dim ratio was 16:1 or 160:1. 4. Dim lighting (1.25 lux) preceded by a period of normal lighting (5 lux or 50 lux) and followed by 8 h darkness was treated as part of the photoperiod. 5. It is concluded that, when there is no darkness, a period of dim lighting is treated as darkness, provided the contrast between bright and dim phases is sufficient. However, when darkness, dim light and bright light are all included in a cycle, the dim light is treated as part of the photoperiod, even though there may be a contrast between the brightly lit and dimly lit phases which, in the absence of darkness, would cause the dim phase to be treated as dark.  相似文献   

Comparison of the pharmacokinetics and thermal antinociceptive pharmacodynamics of 20 µg kg⁻¹ buprenorphine administered sublingually or intravenously in cats     

BDX  Lascelles †  SA Robertson ‡  PM Taylor§  J Hauptman¶ 《Veterinary anaesthesia and analgesia》2003,30(2):108-108

Little is known about the analgesic action of buprenorphine (BUP) in cats. Relative to man, the cat has a more alkaline oral pH, which may make this an effective route for administering BUP in this species. This study aimed to assess and compare the pharmacokinetics and pharmacodynamics of sublingual (S‐L) and IV administration of BUP. Thermal threshold (TT) was measured and blood samples were collected following IV or S‐L administration (20 µg kg^?1) of the injectable formulation. Six cats (five spayed females, one castrated male, 4.1–6.6 kg) were used. Each cat received both treatments in a randomized cross‐over study design with 1 month between experiments. Twenty‐four hours prior to each study, the lateral thorax of each of the cats was shaved, cephalic and jugular catheters placed, and oral pH measured. On the day of the study, TT was measured using a ‘thorax‐mounted’ thermal threshold‐testing device specifically developed for cats. The cats were free to move around. Skin temperature was recorded before each test, then the heater activated. When the cat responded by flinching, turning, or jumping, the stimulus was terminated and the threshold temperature was recorded. The thermal threshold cut‐off point was 55.5 °C. Three baseline thresholds were recorded before treatment with S‐L or IV (via cephalic catheter) BUP (20 µg kg^?1). Blood was withdrawn (jugular) at 1, 2, 4, 6, 10, 15, 30, 45, 60 minutes and at 2, 4, 6, 8, 12, and 24 hours post‐administration. TT was measured every 30 minutes?6 hours, 1–12 hours, and at 24 hours post‐administration. Plasma was immediately separated, stored at ?20.5 °C, and assayed within 4 months using a commercially available ¹²⁵I radioimmunoassay. Threshold data were analyzed using anova with a repeat factor of time. No adverse effects were noted. Pupils were dilated for up to 9 hours post‐BUP. Behavioral changes were calm euphoria. Measured oral pH was 9 in each cat. Pre‐treatment mean threshold (±SD) was 41.2 ± 0.9 °C in the S‐L group and 40.8 ± 0.85 °C in the IV group. There were no significant differences between the groups with respect to thresholds over time (p = 0.72). Thresholds were significantly increased from 30 to 360 minutes in both the groups (>44.615 °C). Peak plasma BUP (C_max) was lower (11 ± 6.7 ng mL^?1vs. 92.9 ± 107.9 ng mL^?1) and occurred later (T_max) (30 minutes vs. 1 minute) after S‐L compared to IV administration, respectively. BUP (20 µg kg^?1)‐administered S‐L or IV provided antinociception between 30 and 360 minutes after administration. Plasma levels did not correspond to TT.  相似文献