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荒漠草地四种灌木单株生物量估测方法 总被引：3，自引：0，他引：3
研究了砾石荒漠草地下松叶猪毛菜，合头草，中亚木紫菀，和琵琶柴的形体特征与产量的关系，建立了估算四种灌木生物量的回归公式：松叶猪毛菜：ｙ＝－５３．２６２６＋２．３５５Ｘ１＋０．９０６２Ｘ２＋０．５６０６Ｘ３，合头草：ｙ＝－１７．８２２８＋０．９２２６Ｘ１＋０．３９６５Ｘ２＋１．０５３１Ｘ３，中亚木紫菀：ｙ＝－１７．２３５６＋０．７３３９Ｘ１＋０．４０６８Ｘ２＋０．７０３４Ｘ３，琵琶柴：ｙ＝－２１．３ 相似文献
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黄河故道沙荒草地生物量及营养价值特性研究 总被引：3，自引：0，他引：3
对黄河故道沙荒草地生物量季节变化规律以及牧草营养物质出动态进行了分析，结果表明：（１）沙荒草地牧草生物量的增长呈二次曲线变化规律：ｙ＝１／（３．７９×１０＾－７ｔ＾２－９．３２×１０＾－５ｔ＋７．８３×１０＾－３），并且其生物量在９月份达到最大值；（２）从５月份开始沙荒草地牧草营养价值逐渐降低，且于物质消化率（ＤＭＤ）与其粗蛋白质（ＣＰ），木质素（ＬＩＧ）含量分别表现为显著正相关（ｒ＝０．９４）和 相似文献
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不同放牧率对混播草地牧草与羔羊生产的影响 总被引：2，自引：0，他引：2
通过三种放牧率对混播草地牧草和羔羊生产的影响进行了研究。结果表明，随着放牧率的增加，牧草产量、叶面积指数明显下降（Ｐ＜０．０５）并使茎叶比显著减少（Ｐ＜０．０５）。放牧率的增大，羔羊个体生产速度显著降低（Ｐ＜０．０１），单位面积的畜产品产量依次为中组＞低组＞高组。并得出羔羊生长量与放牧强度及采食牧草干物质量存在密切关系，同时放牧率影响肉的品质，放牧率不同，草地系统生物学转化效率中组比低、高组高，且草地生产能力最大。由此得出，混播草地以中等放牧率为最佳。 相似文献
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不同类型草地监测与估产遥感指标和光学模型建立的研究 总被引：3，自引：0，他引：3
对１９９１－１９９３年在新疆阜康县不同草地类型上观测的牧草产量、环境资料与地面光谱资料等进行的多重相关分析和光学模型建立的研究结果表明，不同类型的草地产量与各咱光谱工值间存在着显著相关性（Ｐ〈０．０５），相关系数（ｙ）均达到０．８４以上，且通过Ｆ检验。在找出影响牧草类型地面光谱绿度值的时空变化规律，建立了最优草地监测与估产指标和模型，其模型精度较高可用于草地资源大面积监测和估产。 相似文献
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丰草季人工草地划区轮牧,考尔木（Ｃｏｒｍｏ）成年母羊群采食量与怀孕日龄间呈显著正相关,回归方程＾／ｙ＝０．０２６ｘ＋０．６４２２,相关系数ｒ＝０．８１２３,受孕前采食ＤＭ量０．６４ｋｇ／只,产羔前采食ＤＭ量１．０３ｋｇ／只,平均采食ＤＭ量０．８４ｋｇ／只。 相似文献
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水地紫花苜蓿草地氮磷酸比试验效益分析 总被引：5，自引：1，他引：4
氮、磷配施对第５年生紫花苜蓿草地增产不明显，单施磷肥效果极显著。施磷量（Ｘ）与苜蓿风干草产量的回归方程为：ｙ－４２２６．３２＋５３．２８ｘ－０．４７３７ｘ＾２。确定了最佳经济施磷量和施磷量上、下限及相应苜蓿风干草产量。 相似文献
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在河西走廊地区建植碱茅（Ｐｕｃｃｉｎｅｌｌｉａｔｅｎｕｉｆｌｏｒａ－Ｐ．ｃｈｉｎｕｍｐｏｅｎｓｉｓ）人工草地，做收种和刈割兼用。撒播方式下，播量达２２．５ｋｇ／ｈｍ２时，种子落种数为２０００／ｍ２，田间出苗数７９４／ｍ２，出苗率为１３％，定苗数受地表积盐程度的影响（Ｐ＜０．０１），地表盐斑为５０％，９０％的幼苗数为９８８株／ｍ２和３０１株／ｍ２；碱茅草地盖度，种子产量和牧草产量均与土壤全盐含量呈负线性关系（ｒ－－０．８０５１，ｒ＝－０．８１５８，ｒ＝－０．９２９２），但种子发芽率和千粒重似乎不受立地土壤盐分的影响。由于受田间管理措施和碱茅自身发育节律的影响，生长第３年的草地盖度、种子产量和牧草产量均比第２年有不同幅度的下降，据此，适时灌水，加强施肥等田间管理措施对维持草地基况良好，获得高产有重要作用。 相似文献
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用灰色关联分析方法，对刚察县草地建设投资与草地产出作相关分析，初步结果表明，两者相关性强，关联系数大。在草地围栏、畜棚、人工种草、灭鼠、灭治毒杂草、灭虫及６项合计的７个比较列中，其关联度最大的是６项合计的综合效益；其次是草地围栏投资，再次为灭治鼠害投资，人工种草、灭治毒杂草、灭治害虫分别居第五、第六、第七位。草地产出与多种因子有关，如技术措施、劳动者素质、经营水平和科技投入等。若仅分析草地基本建设投资与草地产出的关系，而忽略其他因素的影响，其结果似有以偏盖全之嫌，因此，只能供草地建设投资者做参考。 相似文献
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磷对奶牛红细胞膜脂质的影响 总被引：5，自引：0，他引：5
对１５例临床上有明显低磷血症的奶牛血清磷、红细胞膜脂质成分进行了测定。结果表明，低磷血症奶牛血清磷、红细胞膜磷脂明显降低；红细胞膜胆固醇及膜胆固醇／磷脂摩尔比值（ｎｃｈ／ｎｐｌ）明显升高，与健康对照组牛相比差异极显著（Ｐ＜０．０１）；直线相关分析表明，血清磷与红细胞膜磷脂之间呈极显著正相关（ｒ＝０．９１７，ｙ＝１０．８５２ｘ＋３．１９６，Ｐ＜０．０１）；与红细胞膜胆固醇以及ｎｃｈ／ｎｐｌ之间分别呈显著负相关（ｒ＝－０．９４０，ｙ＝２．８５０ｘ－１．０７２，Ｐ＜０．０１；ｒ＝－０．９２０，ｙ＝１．９６８ｘ－１．４０１，Ｐ＜０．０１）。此外，红细胞膜微粘度与膜磷脂之间呈显著负相关（ｒ＝－０．９５４，ｙ＝１９．１２２ｘ－４．３８４，Ｐ＜０．０１），而与膜胆固醇以及ｎｃｈ／ｎｐｌ之间呈显著正相关（ｒ＝０．９８８，ｙ＝０．９２７ｘ＋０．９６４，Ｐ＜０．０１；ｒ＝０．９７８，ｙ＝－０．２９３ｘ＋１．１１３，Ｐ＜０．０１）。结果表明，磷是红细胞膜脂质成分改变的先决因素，而后者又是红细胞膜流动性及膜结构、功能发生变化并导致膜损伤的一个重要因素。 相似文献
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Meschan EM Peham C Schobesberger H Licka TF 《Veterinary journal (London, England : 1997)》2007,173(3):578-584
As there is no statistical evidence that saddle fit influences the load exerted on a horse's back, this study was performed to assess the hypothesis that the width of the tree significantly alters the pressure distribution on the back beneath the saddle. Nineteen sound horses were ridden at walk and trot on a treadmill with three saddles differing only in tree width. Kinetic data were recorded by a sensor mat. A minimum of 14 motion cycles were used in each trial. The saddles were classified into four groups depending on fit. For each horse, the saddle with the lowest overall force (LOF) was determined. Saddles were classified as "too-narrow" if they were one size (2 cm) narrower than the LOF saddle, and "too-wide" if they were one size (2 cm) wider than the LOF saddle. Saddles two sizes wider than LOF saddles were classified as "very-wide". In the group of narrow saddles, the pressure in the caudal third (walk 0.63 N/cm(2)+/-0.10; trot 1.08 N/cm(2)+/-0.26) was significantly higher compared to the LOF saddles (walk 0.50 N/cm(2)+/-0.09; trot 0.86 N/cm(2)+/-0.28). In the middle transversal third, the pressure of the wide saddles (walk 0.73 N/cm(2)+/-0.06; trot 1.52 N/cm(2)+/-0.19) and very-wide saddles (walk 0.77 N/cm(2)+/-0.06; trot 1.57 N/cm(2)+/-0.19) was significantly higher compared to LOF saddles (walk 0.65 N/cm(2)+/-0.10/ 0.63 N/cm(2)+/-0.11; trot 1.33 N/cm(2)+/-0.22/1.27 N/cm(2)+/-0.20). This study demonstrates that the load under poorly fitting saddles is distributed over a smaller area than under properly fitting saddles, leading to potentially harmful pressures peaks. 相似文献
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M. Masko M. Domino K. Skierbiszewska Ł. Zdrojkowski T. Jasinski Z. Gajewski 《Equine Veterinary Education》2020,32(12):654-663
Complications in late gestation are challenging problems for the equine clinician and are causes of considerable distress to owners. Health problems in a pregnant mare in each stage of gestation can adversely affect the pregnancy. It is important to obtain a thorough history and perform a detailed and systematic examination of the pregnant mare so that the mare may be classified as normal or high-risk. However, even after a thorough examination, practitioners may face problems with the interpretation and assessment of risk. Normal mares should foal in the stable or pasture. Mares classified as having a high-risk pregnancy need to be monitored precisely for signs of oncoming foaling with attendance of trained personnel when labour begins. A valuable method for monitoring of the high-risk mare is assessing fetoplacental well-being. Fetoplacental well-being is most accurately assessed with ultrasonography as well as several available hormone profiles. We are proposing our scoring system of the mare's health, which may be useful in the assessment of risk during pregnancy and help clinicians to decide whether sending the mare to the clinic is reasonable or unnecessary. 相似文献
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为了找出支配鸡胆囊交感节后神经元的分布规律,选用体重1.5 kg～2.5 kg的成年母鸡6只,将CT-HRP溶液注入胆囊壁,动物存活3 d～4 d后,经左心室灌流固定,取内脏神经节、肾上腺神经节以及双侧胸、腰和荐段交感干神经节,制成50 μm的连续冰冻切片,TMB法呈色反应,置明视野显微镜下观片统计.结果发现,支配鸡胆囊的交感传出神经元胞体位于内脏神经节(占41.1%)、肾上腺神经节(占40.5%)和T2～T7交感干神经节(占18.4%),在交感干神经节中标记细胞的峰值位于T5、T6交感干神经节.所有的标记细胞以位于右侧的占优势. 相似文献
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Webbon P 《Equine veterinary journal》2012,44(1):8-12
The understanding and application of genetics have grown extremely quickly since it has become possible to sequence the whole genome of an organism. The human genome sequence was completed in 2001 and that of the horse in 2007. The significance of this is that it makes it more feasible to explain how both genetically simple and complex traits are transmitted from one generation to the next and, therefore, to make informed breeding decisions, modify how horses are managed and trained to minimise the risk of disease and injury, and improve methods of prevention, diagnosis and treatment of many conditions. The science of genetics/genomics will continue to grow internationally, limited only by the funds available. The application of the science to man, horses and other species raises very complex moral and commercial issues. Thoroughbred breeders are perceived by some as resistant to change, but their apparent intransigence is often based on a genuine concern for the integrity of the breed. By taking control of the application of the advances in genetics, the Thoroughbred industry potentially has the opportunity to improve both the health and performance of Thoroughbreds. If, however, the science is applied in an uncoordinated manner, driven by commercial interests with no underlying concern for the horses themselves, there is a very real risk that breeders, the Thoroughbred breed and individual horses will all suffer as a consequence. 相似文献
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犊牛腹泻与肠道菌群的变化 总被引：1，自引：0，他引：1
本文检测腹泻犊牛的直肠内8种主要正常菌群的变化,并与健康犊牛进行对比。结果发现,犊牛腹泻时,大肠杆菌、双岐杆菌和乳杆菌变化较大,而其它菌群变化较小。腹泻或将腹泻时,大肠杆菌数增加,双岐杆菌和乳杆菌数下降。腹泻康复或即将康复时,大肠杆菌减少,双岐杆菌、乳杆菌数增加。 相似文献
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试验选择陕北白绒山羊繁育中心羊场的成年健康母羊（怀孕前期）16只,育成母羊13只,育成公羊13只,空腹称重。测定每只羊1d的采食量,计算其摄入的营养成分含量,并与原苏联绒用山羊饲养标准比较,进行饲养水平评价。结果显示,与饲养标准比较,陕北白绒山羊繁育中心羊场的育成母羊代谢能高2．68MJ,粗蛋白低59．29g,钙低3．00g,磷低1．52g;育成公羊代谢能高3．47MJ,粗蛋白低81．92g,钙低4．42g,磷低2．62g;成年母羊代谢能高2．51MJ,粗蛋白低91．33g,钙低3．09g,磷低1．93g。结合羊的体况综合评价饲养水平基本合理,但尚需要按饲养标准增加粗蛋白、钙、磷等营养物质的供给量。 相似文献
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Evidence for the non-involvement of the uterus in the lifespan of the corpus luteum in the cyclic dog 总被引：1，自引：0，他引：1
Progesterone levels in peripheral blood of dogs were analysed during the cycle in which hysterectomy (n = 5) or sham surgery (n = 3) was performed as well as during the cycle of dogs (n = 5) hysterectomized at least one year prior to this study; the data were compared with the findings in control dogs (n = 3). The averages of the duration of the luteal period observed in the three experimental groups were not significantly different from those of control dogs. Immediately after surgery, the progesterone level decreased from 25 to 50% of the presurgical level, but returned to presurgical level in about four days. Prolactin levels were elevated for about 30 h after surgery. Nevertheless, the averages of the mean prolactin levels for each animal during the luteal period of the experimental groups were not significantly different from those of control dogs. It is concluded that in the dog, the uterus is not involved in the lifespan of the cyclic corpus luteum. 相似文献