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保育仔猪饲养管理比日粮配方更加重要   总被引:3,自引:0,他引:3  
对早期断奶仔猪而言,一套成功的饲养管理制度必须要克服几方面的问题,而其中的许多问题是相互关联的。因此,一旦这些问题中的某一个出现了显著的不足,虽然仍能制订出可以接受的饲养管理方案,但将使仔猪的生产性能低于期望值。我们研究了许多种生产方式,并与各种各样的人打交道,  相似文献   
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An experiment using 264 crossbred barrows was conducted to examine the interaction between space allocation and dietary ractopamine addition on pig performance and carcass characteristics using a 2 x 2 factorial arrangement of treatments. Treatments were 0.55 (19 pigs per pen) or 0.74 (14 pigs per pen) m2/pig from start (29.7 +/- 0.1 kg BW) to slaughter (108 kg BW) in a fully slatted facility and 0 or 10 ppm (as-fed basis) ractopamine for 28 d before slaughter. There were few treatment interactions. Pigs given 0.55 m2/pig had a lower ADG (P = 0.010), ADFI (P = 0.088), 10th-rib backfat depth on d 86 (P = 0.010), and carcass loin muscle depth (P = 0.011) than pigs given 0.74 m2/pig. There was no difference in feed conversion (P = 0.210) as a result of space allocation. Pigs fed diets containing 10 ppm ractopamine had decreased (P = 0.004) ADFI and improved (P = 0.001) feed conversion efficiencies for the 28-d feeding period, along with greater loin depth (P = 0.005) and carcass lean percent (P = 0.001). The improvements in 28-d carcass lean growth associated with feeding 10 ppm ractopamine resulted in an improvement in overall daily fat-free lean gain (P = 0.046). Under these experimental conditions, the response to dietary ractopamine was similar for crowded and uncrowded pigs.  相似文献   
157.
The Skills, Knowledge, Aptitude, and Attitude (SKA) Subcommittee of the National Commission on Veterinary Economic Issues (NCVEI) has identified the need for veterinary teaching hospitals (VTH) to be at the forefront of progressive business management to serve as a model for both students and practitioners to emulate. To provide a foundation for developing a model, this study reviewed pertinent literature applicable to the management of a VTH. Much of the literature relevant to VTH management relates to work completed for the human side of medicine (academic health centers, or AHCs) or to the private sector. This review explores management practices in strategic planning, financial management, human resource management, marketing, pricing, operations, and legal issues. It is concluded that strategic management is important to provide the foundation for success in the VTH. In addition, periodic financial reports are recommended, as are the development and use of benchmarks for financial management. Establishing positive, motivating human resource practices is also suggested, along with development of a marketing plan based on a clear understanding of VTH core competencies and the market's specific needs.  相似文献   
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Fel-O-Vax FIV is an inactivated virus vaccine designed as an aid in the prevention of infection of cats, 8 weeks or older, by feline immunodeficiency virus (FIV). It contains two genetically distinct FIV strains. The efficacy of this vaccine was demonstrated in a vaccination-challenge study designed to meet various regulatory requirements for registering the vaccine. Eight-week-old kittens were vaccinated with an immunogenicity vaccine which contained minimal release levels of FIV antigens formulated with a proprietary adjuvant system. Twelve months later, all vaccinates and controls were challenged with a heterologous FIV strain. Following the vigorous challenge exposure, cats were monitored for FIV viremia. It was found that 16% of the vaccinated cats developed viremia while 90% of the controls became persistently infected with FIV, which demonstrated that the vaccine was efficacious and the protective immunity lasted for at least 12 months. The safety of the vaccine was demonstrated by a field safety trial in which only 22 mild reactions of short duration were observed following administering 2051 doses of two pre-licensing serials of Fel-O-Vax FIV to cats of various breeds, ages and vaccination histories. Thus, Fel-O-Vax FIV is safe and efficacious for the prevention of FIV infection in cats.  相似文献   
159.
To test the direct regeneration hypothesis and support natural disturbance-based forest management we characterized the structure and composition of boreal mixedwood forests regenerating after large wildfires and examined the influence of pre-fire stand composition and post-fire competing vegetation. In stands which had been deciduous (Populus sp.)-dominated, conifer (white spruce)-dominated, or mixed pre-fire we measured regeneration stocking (presence in 10 m2 plots), density and height 10–20 years post-burn in five wildfires in Alberta, Canada. Most plots regenerated to the deciduous or mixed stocking types; plots in the older fire and in stands that were pure conifer pre-fire had higher amounts of conifer regeneration. Surprisingly, regeneration in pre-fire ‘pure’ white spruce stands was most often to pine, although these had not been recorded in the pre-fire inventory. Pre-fire deciduous stands were the most resilient in that poplar species dominated their post-fire regeneration in terms of stocking, density and height. These stands also had the highest diversity of regenerating tree species and the most unstocked plots. High grass cover negatively affected regeneration density of both deciduous and conifer trees. Our results demonstrate the natural occurrence of regeneration gaps, pre- to post-fire changes in forest composition, and high variation in post-fire regeneration composition. These should be taken into consideration when developing goals for post-harvest regeneration mimicking natural disturbance.  相似文献   
160.
In our paper we will try to connect the dynamics of community decline to individual responses. We will operate on two levels of reality. At the first level we will discuss the circumstances surrounding the recent decline of small communities in North Dakota. At the second level we will discuss how this decline affects small town residents' attitudes toward economic development. In the first level analysis we examine the thesis that the natural environment of community growth is economic exploitation; therefore, the decline of resource-based communities is natural and inevitable. We discuss the circumstances surrounding the recent decline of small communities in North Dakota. At the second level analysis, we operate at the level at which life circumstances and environments are shaped by political-economic institutions that in turn shape the behavior and mentality of communities, families, and individuals. We hypothesize that residents of declining small towns deny their powerlessness and adapt to their situation through intense dedication to economic growth. We develop a series of hypotheses to test this thesis using data from the North Dakota Rural Life Poll. In our conclusion, we discuss implications for rural development practitioners working in declining small towns where this intense dedication to economic development in prevalent.Dr. Stofferahn is an assistant professor in the Department of Sociology and director of the Social Science Research Institute at the University of North Dakota. He received his Ph.D. and M.S. in rural sociology from Iowa State University. Prior to coming to the University of North Dakota, Dr. Stofferahn was employed by the North Dakota Economic Development Commission. Mr. Fontaine received his M.S. in sociology from the University of North Dakota and is presently employed as the assistant director of the Social Science Research Institute. Douglas McDonald, Mike Spletto and Holly Jeanotte are graduate students in the Department of Sociology at the University of North Dakota. This paper originally was written as a class project in a graduate seminar in rural development.  相似文献   
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