Aboveground biomass production of a semi-arid southern African savanna: towards a new model     

Anthony R Palmer  Igshaan Samuels  Clement Cupido  Andiswa Finca  W Fransiska Kangombe  Isa AM Yunusa 《African Journal of Range and Forage Science》2016,33(1):43-51

Following a field campaign to determine the species composition, canopy cover, aboveground annual production and leaf area index (LAI) of the semi-arid savanna of north-western Namibia, we present a production model that can be used by graziers to determine the livestock carrying capacity. The model predicts the annual aboveground net primary production (ANPP) from regression equations of canopy cover by annual production fraction for plant functional classes. We tested the output of the model against another fully independent net primary production (NPP) model, namely the MODIS NPP product. The mean MODIS NPP for the 29 sites was 343 ± 22?kg dry matter (DM) ha^?1 y^?1 as opposed to 285 ± 142?kg DM ha^?1 y^?1 for the fAP model that used the regression method (p < 0.01). As a proof of concept, these landscape-scale ANPP values are used to calculate a recommended livestock carrying capacity for the Ehirovipuka Communal Conservancy, a 1 980 km² communal area with both wildlife and livestock populations. In addition, we also provide details of a field method for predicting landscape-scale LAI from line transect data. This approach can be used to ground reference the LAI values generated from the MODIS LAI product.  相似文献   

Diagnosis and ultrasonographic appearance of hepatic metastasis in six cases of canine appendicular osteosarcoma (2005–2013)          下载免费PDF全文

L Cesario  LD Garrett  AM Barger  RT O'Brien  TM Fan 《Australian veterinary journal》2016,94(5):160-165

  相似文献   

Negative pressure wound therapy using a portable single‐use device for free skin grafts on the distal extremity in seven dogs          下载免费PDF全文

AJ Miller  RG Cashmore  AM Marchevsky  M Havlicek  PM Brown  SM Fearnside 《Australian veterinary journal》2016,94(9):309-316

  相似文献   

Obtaining Wisent early blastocyst in vitro is a basic for protection and creation of biodiversity for this threatened species          下载免费PDF全文

AM Duszewska  P Gręda  M Baraniewicz  W Bielecki  W Niżański  A Partyka  M Tracz  Z Nowak  A Chełmońska‐Soyta  W Olech 《Reproduction in domestic animals》2018,53(3):818-821

Wisent, or European bison (Bison bonasus), is listed as “vulnerable” on the IUCN Red List of Threatened Species and is therefore protected by international law. For the first time, a Wisent embryo has been obtained in vitro. This procedure creates a new opportunity to protect and increase Wisent reproductive potential and thereby opens new possibilities for the establishment of a controlled and broad reserve of the gene pool.  相似文献   

A comparative study of three veld types of the Northern Cape: Species evaluation and yield 1     

J. H. Fourie  B. R. Roberts 《African Journal of Range and Forage Science》2013,30(1):79-85

A comparative study was undertaken of the grass component of the three main veld types of the Vryburg district; namely Sand veld, Dolomite veld and Lime veld. Results indicate that different species within the same veld type and the same species in different veld types differ in their dry matter production, digestibility and digestible organic matter production. Botanical composition and basal cover also varied between veld types. Veld types also differ in DM yields, digestibility and DOM yield.

The average digestibility of all species at three growth stages (leafy, flowering and mature) was 48,7% in sand veld, 54,8% in dolomite veld and 54,7% in lime veld. The average dry matter production and digestible organic matter production per m² at three growth stages were 2 083,9 g and 844,5 g in Sand veld, 2 108,6 g and 952,5 g Dolomite veld, and 1 776,0 g and 808,8 g in Lime veld, respectively. The possibility of deficiencies of Zn, Cu and P is indicated in all three veld types.

The percentage basal covers of sand veld, Dolomite veld and Lime veld were 4,3%, 2,1% and 5,0% respectively. The average DM yield and DOM yield of the veld types were 786,4 and 301,1 kg/ha in Sand veld, 403,9 and 189,2 kg/ha in Dolomite veld, and and 365,7 kg/ha in Lime veld respectively. The average digestibility of the veld types were 44,0%in Sand veld, 56,3% in Dolomite veld and 52,3% in Lime veld.  相似文献   

Efficiency of Two Enucleation Methods Connected to Handmade Cloning to Produce Transgenic Porcine Embryos     

J Li  K Villemoes  Y Zhang  Y Du  PM Kragh  S Purup  Q Xue  AM Pedersen  AL Jørgensen  JE Jakobsen  L Bolund  H Yang  G Vajta 《Reproduction in domestic animals》2009,44(1):122-127

The purpose of our work was to establish an efficient-oriented enucleation method to produce transgenic embryos with handmade cloning (HMC). After 41–42 h oocytes maturation, the oocytes were further cultured with or without 0.4 μg/ml demecolcine for 45 min [chemically assisted handmade enucleation (CAHE) group vs polar body (PB) oriented handmade enucleation (OHE) group respectively]. After removal of the cumulus cells and partial digestion of the zona pellucida, oocytes with visible extrusion cones and/or polar bodies attached to the surface were subjected to oriented bisection. Putative cytoplasts without extrusion cones or PB were selected as recipients. Two cytoplasts were electrofused with one transgenic fibroblasts expressing green fluorescent protein (GFP), while non-transgenic fibroblasts were used as controls. Reconstructed embryos were cultured in Well of Wells (WOWs) with porcine zygote medium 3 (PZM-3) after activation. Cleavage and blastocyst rates were registered on day 2 and day 7 of in vitro culture respectively. Meanwhile, the total blastocyst cell number was counted on day 7. We found that the difference was only observed between blastocyst rates (38.6 ± 2% vs 48.1 ± 3%) of cloned embryos with GFP transgenic fibroblast cells after CAHE vs OHE. With adjusted time-lapse for zonae-free cloned embryos cultured in WOWs with PZM-3, it was obvious that in vitro developmental competence after CAHE was compromised when compared with the OHE method. OHE enucleation method seems to be a potential superior alternative method used for somatic cell nuclear transfer (SCNT) with transgenic fibroblast cells.  相似文献   

A study of the pathology and pathogenesis of the myocardial lesions in gousiekte, a plant-induced cardiotoxicosis of ruminants     

Prozesky L  Bastianello SS  Fourie N  Schultz RA 《The Onderstepoort journal of veterinary research》2005,72(3):219-230

Myocardial lesions were studied in sheep in which gousiekte was induced by experimental dosage of Pachystigma pygmaeum, Fadogia homblei or Pavetta harborii. The single most consistent diagnostic histological feature in 33 animals was hypertrophy of myocardial fibres in the subendocardial region. Fibrosis in the subendocardial region of the apex or left ventricular wall was often scarce or absent in animals with a short latent period, and was not always prominent even in sheep with an intermediate or long latent period. The presence or absence of fibrosis cannot therefore be used to confirm or exclude gousiekte, particularly in cases with shorter latent periods. Light microscopical and ultrastructural lesions in sheep with gousiekte correspond to a large extent to changes reported in humans with dilated cardiomyopathy of unknown cause. It appears that the myocardial lesions in gousiekte represent a final common pathway of cellular damage rather than a manifestation of a specific type of heart disease. The predilection for hypertrophy of myofibres in the subendocardial region is probably related to diminished perfusion that potentiates the primary myocardial dysfunction.  相似文献   

Elephant shrews as hosts of immature ixodid ticks     

Fourie LJ  Horak IG  Woodall PF 《The Onderstepoort journal of veterinary research》2005,72(4):293-301

Two hundred and seventy-three elephant shrews, consisting of 193 Elephantulus myurus, 67 Elephantulus edwardii and 13 animals belonging to other species, were examined for ixodid ticks at 18 localities in South Africa and Namibia. The immature stages of Ixodes rubicundus, Rhipicentor nuttalli, Rhipicephalus warburtoni and a Rhipicephalus pravus-like tick were the most numerous of the 18 tick species recovered. Substantial numbers of immature Rhipicephalus arnoldi, Rhipicephalus distinctus and Rhipicephalus exophthalmos were also collected from elephant shrews at particular localities. Larvae of I. rubicundus were most numerous on E. myurus in Free State Province from April to July and nymphs from June to October. Larvae of R. nuttalli were most numerous on these animals during April, May, August and September, and nymphs in February and from April to August. The immature stages of R. warburtoni were collected from E. myurus only in Free State Province, and larvae were generally most numerous from December to August and nymphs from April to October.  相似文献   

Comparison of 3 tests to detect acaricide resistance in Boophilus decoloratus on dairy farms in the Eastern Cape Province,South Africa     

Mekonnen S  Bryson NR  Fourie LJ  Peter RJ  Spickett AM  Taylor RJ  Strydom T  Kemp DH  Horak IG 《Journal of the South African Veterinary Association》2003,74(2):41-44

The susceptibility of the larval offspring of engorged female Boophilus decoloratus, and of the engorged females, collected from cattle on the dairy farms Brycedale, Sunny Grove and Welgevind in the Eastern Cape Province, South Africa, was tested against the acaricides amitraz, chlorfenvinphos and cypermethrin. Resistance was determined by means of the Shaw Larval Immersion Test (SLIT) for larvae and the Reproductive Estimate Test (RET) and Egg Laying Test (ELT) for adults. At Brycedale the tests all indicated resistance to chlorfenvinphos, and RET and ELT indicated resistance to amitraz and emerging resistance to cypermethrin. At Sunny Grove, B. decoloratus was resistant to cypermethrin using SLIT and exhibited emerging resistance to chlorfenvinphos with SLIT and to cypermethrin with both RET and ELT At Welgevind, resistance was recorded against chlorfenvinphos (SLIT) and against cypermethrin (ELT), and emerging resistance against permethrin (RET). The results obtained with RET and ELT were generally comparable, but often differed from those obtained with SLIT. Resistance could be detected within 7 days with ELT compared to 42 days with RET and 60 days with SLIT.  相似文献   

Graduates in Veterinary Science     

Martin AM  Currie E. 《Australian veterinary journal》2004,82(8):496-496

  相似文献