نتایج جستجو برای: grazing systems

تعداد نتایج: 1196379  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم پایه دامغان 1389

in this thesis, ‎‎using‎‎ ‎concept‎s‎ ‎of‎ ‎wavelet‎s‎ ‎theory ‎‎‎som‎e‎ ‎methods‎‎ ‎of‎ ‎th‎e ‎solving‎‎ ‎optimal‎‎ ‎‎con‎tr‎ol‎ problems ‎(ocps)‎‎. ‎g‎overned by time-delay systems is investigated. ‎th‎is‎ thesis contains ‎tw‎o parts. ‎‎first, the method of obtaining ‎o‎f ‎the‎ ‎‎ocps‎ in time delay systems by linear legendre multiwavelets is ‎ ‎presented‎.‎‎‎‎ the main advantage of the meth...

Journal: :Journal of dairy science 2014
S P Washburn K A E Mullen

Pasture-based dairy systems use grazing to supply significant percentages of the dry matter intake of cows and heifers. Such systems vary from those for which pasture is used only as a supplemental feed for cows primarily fed a total mixed ration to those for which pasture is the primary source of dry matter for the herd. Cows that are optimal in a pasture system share many general characterist...

2011
J. L. Beck R. D. Mealor B. W. Hess G. E. Moss S. L. Lake

Changes in commodity pricing and environmental concerns are changing animal agriculture throughout the United States. Adopting multispecies grazing as an alternative production system could result in improved forage utilization, increased animal performance, and reduced production costs, and thereby improve the financial stability of livestock operations. This study focused on the Silver Spur R...

Journal: :Agronomy 2022

The usage of grassland significantly affects the microbial and biochemical parameters soil epipedons. use grasslands (by mowing, grazing, mowing grazing) dominance bacteria in abundance relative to fungal populations. This was particularly noticeable when manual applied. In general, highest number microorganisms occurred during spring summer, which should be associated with intensity growth roo...

ژورنال: مرتع 2021
Akbarloo, Moosa, Barani, Hossein, Darvishi, Leila, Ghelichnia, Hassan,

Attention to the quality and quantity of forage plants, palatability and species preference, are among the information needed to properly manage pasture grazing. One of the prominent plants in the Nour Rud rangelands are Allium spp plants that have an acceptable distribution in the area. For the sake of the study, the preferred value of different species of Allium’s for Shal sheep with an avera...

2006
Temuulen Tsagaan Sankey Cliff Montagne Lisa Graumlich Rick Lawrence Jerry Nielsen

We studied five lower forest–grassland ecotones in the Darhad Valley in northern Mongolia and investigated the effects of 20th Century grazing regimes and changes in grazing management on ecotone dynamics at a local scale. A total of 2968 Siberian larch (Larix sibirica) trees were cored and tree-age distribution was constructed to determine 20th Century tree establishment. Tree age and location...

1998
JOHN W. WALKER RODNEY K. HEITSCHMIDT

Research was conducted on the effects of rotational grazing (RG) compared to continuous grazing (CG) on the behavior of cattle grazing on rangelands. Different livestock den&tics in the RG treatments were created by varying the size of paddocks in a 4651a, U-paddock, cell deaigntd RG treatment stocked at a rate of 3.6 ha/cow/yr. Paddock sizes of 30 and lo-ha were used to simulate RG with 14 (RG...

Journal: :Ecotoxicology 2009
P Madejón M T Domínguez J M Murillo

Pasture established on polluted soil may pose a risk to grazing livestock creating a requirement for mechanical management which may affect biodiversity and expend energy. The risk associated with managing pasture by grazing horses (non-edible livestock) is being assessed in the Guadiamar Valley (SW Spain), where soils are polluted with trace elements following a major pollution incident. Soil ...

2014
Stacy C. Davis Laura A. Burkle Wyatt F. Cross Kyle A. Cutting John F. Valentine

Livestock grazing can be used as a key management tool for maintaining healthy ecosystems. However, the effectiveness of using grazing to modify habitat for species of conservation concern depends on how the grazing regime is implemented. Timing of grazing is one grazing regime component that is less understood than grazing intensity and grazer identity, but is predicted to have important impli...

2010
A. J. Smart J. D. Derner J. R. Hendrickson R. L. Gillen B. H. Dunn E. M. Mousel P. S. Johnson R. N. Gates K. K. Sedivec K. R. Harmoney J. D. Volesky K. C. Olson

Comparisons of stocking rates across sites can be facilitated by calculating grazing pressure. We used peak standing crop and stocking rates from six studies in the North American Great Plains (Cheyenne, Wyoming; Cottonwood, South Dakota; Hays, Kansas; Nunn, Colorado; Streeter, North Dakota; and Woodward, Oklahoma) to calculate a grazing pressure index and develop relationships for harvest effi...

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