نتایج جستجو برای: over grazing

تعداد نتایج: 1149418  

Journal: :Journal of animal science 2009
M E Drewnoski E J Oliphant B T Marshall M H Poore J T Green M E Hockett

The objective of this study was to evaluate the performance of growing cattle when intensively grazing stockpiled endophyte-infected (E+), endophyte-free (E-), and nontoxic endophyte-infected (EN) tall fescue during the winter. The experiment was conducted over 5 consecutive winters. In each year, plots (1 ha each, 4 per treatment) were harvested for hay in August, fertilized in September, and ...

Journal: :Environment international 2001
A C Liedloff M B Coughenour J A Ludwig R Dyer

As savannas are widespread across northern Australia and provide northern rangelands, the sustainable use of this landscape is crucial. Both fire and grazing are known to influence the tree-grass character of tropical savannas. Frequent fires open up the tree layer and change the ground layer from perennials to that dominated by annuals. Annual species in turn produce copious quantities of high...

Journal: :Environmental management 2008
Joseph A Magner Bruce Vondracek Kenneth N Brooks

The U.S. Department of Agriculture-Natural Resources Conservation Service has recommended domestic cattle grazing exclusion from riparian corridors for decades. This recommendation was based on a belief that domestic cattle grazing would typically destroy stream bank vegetation and in-channel habitat. Continuous grazing (CG) has caused adverse environmental damage, but along cohesive-sediment s...

2006
Donald E. Barrick

At grazing, propagation and scatter become inextricably connected. For sufficiently low source/observer heights, free-space inverse-distance propagation no longer applies and plane-wave descriptions of scatter give way to surface-wave modes. Concepts like surface radar cross section must be reinterpreted; lack of awareness of these facts in attempts to correlate measurements with grazing-angle ...

Journal: :Journal of dairy science 2016
J K Lowe C N Boyer A P Griffith J C Waller G E Bates P D Keyser J A Larson E Holcomb

Heifer rearing is one of the largest production expenses for dairy cattle operations, which is one reason milking operations outsource heifer rearing to custom developers. The cost of harvested feedstuffs is a major expense in heifer rearing. A possible way to lower feed costs is to graze dairy heifers, but little research exists on this topic in the mid-south United States. The objectives of t...

Journal: :Environmental management 2014
Robert L Beschta Debra L Donahue Dominick A DellaSala Jonathan J Rhodes James R Karr Mary H O'Brien Thomas L Fleischner Cindy Deacon Williams

Svejcar et al. (Environ Manage, 2014) offered several perspectives regarding Beschta et al. (Environ Manage 51:474-491, 2013)--a publication that addressed the interacting ecological effects of climate change and domestic, wild, and feral ungulates on public lands in the western United States (US)--by largely focusing on three livestock grazing issues: (1) legacy versus current day impacts; (2)...

Journal: :Revista de biologia tropical 2014
Elizabeth A Lacey Ligia Collado-Vides James W Fourqurean

Green sea turtles, Chelonia mydas, are grazers influencing the distribution of seagrass within shallow coastal ecosystems, yet the drivers behind C. mydas patch use within seagrass beds are largely unknown. Current theories center on food quality (nutrient content) as the plant responds to grazing disturbances; however, no study has monitored these parameters in a natural setting without grazer...

2001
JOSEPH L. EASTMAN MIKE B. COUGHENOUR ROGER A. PIELKE

Before European settlement, the Great Plains of the United States contained vast herds of bison. These bison altered the landscape through their grazing. Measurement data of the disturbance that such grazing could produce, when scaled for the large population of bison, were used with a coupled atmospheric–ecosystem model to evaluate the likely effect that this grazing had on the growing season ...

Journal: :Journal of animal science 2012
T S Dennis L J Unruh-Snyder M K Neary T D Nennich

Mixed livestock grazing can offer an alternative management system for rearing dairy replacement heifers (Bos taurus). A 2-yr study was conducted during 2009 (yr 1) and 2010 (yr 2) to determine the effects of co-grazing Holstein heifers under rotational stocking with Boer × Kiko goats on animal performance, pasture DM yield, and botanical composition. Each year, 24 heifers (134 ± 6 d of age and...

Journal: :مرتع و آبخیزداری 0
پریا کمالی دانشجوی کارشناسی ارشد رشتة مرتع داری، دانشکدة منابع طبیعی دانشگاه تربیت مدرس رضا عرفانزاده استادیار گروه مرتع داری دانشکدة منابع طبیعی دانشگاه تربیت مدرس حسن قلیچ نیا استادیار پژوهشی مرکز تحقیقات کشاورزی و منابع طبیعی ساری

this study aimed to investigate the effect of animal grazing on soil seed bank characteristics in the northern slopes of alborz. for this purpose, soil seed bank characteristics were compared between grazed and ungrazed areas. therefore, four transects perpendicular to the sides of exclosure inside and outside of it were established. then soil samples were collected within 28 plots inside and 2...

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