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11.
Der 1967 in Seehausen auf sandigem Lehm angelegte Düngungs‐Kombinationsversuch dient der Analyse von Langzeitwirkungen gestaffelter Stallmist‐ und Mineral‐N‐Gaben (0,50,100,150 kg N ha?1 a?1) auf Pflanzen, Boden und Umwelt. Anhand von Meß‐, Bilanz‐ und Simulationswerten wird die Nachhaltigkeit dieser Düngungsvarianten bewertet. Organisch‐mineralische Düngung führte zu Maximalerträgen von über 12t TM ha?1 a?1 und N‐Entzügen bis 200 kg ha?1 a?1. Der N‐Entzug der ungedüngten Variante betrug in den letzten Jahren noch etwa 75 kg ha?1a?1 gegenüber 100 kg ha?1a?1 zu Versuchsbeginn. Die Entwicklung der Boden‐Nt‐Gehalte konnte mit e‐Funktionen beschrieben werden. Mineral‐N allein genügte nicht zum Erhalt der Nt‐Ausgangsvorräte, hierfür waren 55 bis 85 kg Stalldung‐N ha?1 a?1 notwendig. Die Nt‐ und Ct‐Gehalte korrelierten mit zahlreichen Bodenparametern. Hohe Humusgehalte forderten die biologische Aktivität. Die N‐Verluste betrugen <10kg ha?1 a?1 (ungedüngt) bis 120 kg ha?1a?1 (höchstgedüngte Variante). Das N‐Verlustpotential lag bei Stallmistanwendung etwas niedriger als bei gleicher N‐Zufuhr in Mineralform. Je nach Stallmist‐Stufe waren 62 bis 104 kg Mineral‐N ha?1 a?1 erforderlich, um den Energieeinsatz je Produkteinheit zu minimieren. Kombinierte Anwendung organischer und mineralischer Dünger (je 100 kg N ha?1 a?1) führte zu höchsten ökonomischen Leistungen, günstigen Bodeneigenschaften und tolerierbaren Umweltwirkungen. Zieht man alle verwendeten Nachhaltigkeitskriterien in Betracht, ist dieses Düngungssystem den anderen überlegen. 相似文献
12.
Lindeberg H Kurtén A Koskinen E Katila T 《Zentralblatt für Veterin?rmedizin. Reihe A》1999,46(2):87-90
The effect of addition of glycine betaine to a lactose-EDTA freezing medium on the post-thaw motility of stallion semen was determined. The first three semen-rich fractions of nine stallions were collected with an open-end Krakow artificial vagina on consecutive weekdays. Semen was frozen using the Hannover method with freezing media containing glycine betaine in various concentrations from 0 to 5%. After thawing, sperm motility was analysed both by a light microscope and by a Hamilton-Thorn Motility Analyser. Total and progressive post-thaw motilities of semen containing 0.25-3% glycine betaine did not differ significantly from the total and progressive post-thaw motilities of semen frozen without glycine betaine. The total and progressive post-thaw motilities of semen containing 4 or 5% glycine betaine were significantly lower (P < 0.001) than those of semen without glycine betaine. In conclusion, glycine betaine did not show any beneficial effect on the post-thaw motility of stallion semen when semen was frozen using the Hannover method. 相似文献
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Nielsen C Stover SM Schulz KS Hubbard M Hawkins DA 《American journal of veterinary research》2003,64(5):609-617
OBJECTIVE: To calculate normative joint angle, intersegmental forces, moment of force, and mechanical power at elbow, antebrachiocarpal, and metacarpophalangeal joints of dogs at a walk. ANIMALS: 6 clinically normal mixed-breed dogs. PROCEDURE: Kinetic data were collected via a force platform, and kinematic data were collected from forelimbs by use of 3-dimensional videography. Length, location of the center of mass, total mass, and mass moment of inertia about the center of mass were determined for each of 4 segments of the forelimb. Kinematic data and inertial properties were combined with vertical and craniocaudal ground reaction forces to calculate sagittal plane forces and moments across joints of interest throughout stance phase. Mechanical power was calculated as the product of net joint moment and the angular velocity. Joint angles were calculated directly from kinematic data. RESULTS: All joint intersegmental forces were similar to ground reaction forces, with a decrease in magnitude the more proximal the location of each joint. Flexor moments were observed at metacarpophalangeal and antebrachiocarpal joints, and extensor moments were observed at elbow and shoulder joints, which provided a net extensor support moment for the forelimb. Typical profiles of work existed for each joint. CONCLUSIONS AND CLINICAL RELEVANCE: For clinically normal dogs of a similar size at a walk, inverse dynamic calculation of intersegmental forces, moments of force, and mechanical power for forelimb joints yielded values of consistent patterns and magnitudes. These values may be used for comparison in evaluations of gait in other studies and in treatment of dogs with forelimb musculoskeletal disease. 相似文献
15.
OBJECTIVE: To determine the effects of femoral prosthesis stem length and head size on cement strains in a canine hip replacement system. STUDY DESIGN: An in vitro experimental model. SAMPLE POPULATION: (1) Three standard and 3 1-cm shortened femoral implants with +3 femoral heads. (2) Two standard implants with +0, +3, and +6 femoral heads. METHODS: Femoral stems were embedded in polymethylmethacrylate cement. A uniaxial proximodistal-oriented strain gauge was applied to the cement on the medial and lateral aspects of the construct 1.5 cm, 6.0 cm and 7.0 cm distal to the collar. Each construct with a +3 femoral head was mounted in a materials testing system. An axial compressive load (0-200 N) was applied to the femoral head and cement strains were recorded. Additionally, 2 standard length constructs were also tested with +0 and +6 femoral heads. The effects of stem length and neck length on cement strains were assessed with analysis of variance. RESULTS: Strains increased at all locations with increasing loads for all constructs. Shorter implants had higher strains by 152% and 171%, lateral (P =.003) and medial (P =.0025) to the stem tip. No significant strain differences were noted, at any strain gauge location, between different neck lengths (P values ranged from.20 to.67). CONCLUSIONS: Although a shorter implant stem has a potential to improve implant fit, it led to significantly higher cement strains that may increase the risk for aseptic loosening. Changes in femoral neck length did not significantly affect cement strains under the conditions tested. CLINICAL RELEVANCE: Shortening of the femoral stem currently cannot be recommended in canine total hip replacement. The existing use of variable neck lengths likely does not increase the risk of failure of the femoral stem. 相似文献
16.
Talcott KW Schulz KS Kass PH Mason DR Stover SM 《American journal of veterinary research》2002,63(11):1520-1526
OBJECTIVE: To develop a model for measuring rotary stability of the canine elbow joint and to evaluate the relative contribution of the anconeal process (AN), lateral collateral ligament (LCL), and medial collateral ligament (MCL). SAMPLE POPULATION: 18 forelimbs from 12 canine cadavers. PROCEDURE: Forelimbs were allocated to 3 experimental groups (6 forelimbs/group). Each intact forelimb was placed in extension at an angle of 135 degrees and cycled 50 times from -16 degrees (pronation) to +28 degrees (supination) in a continuous manner at 2.0 Hz. Cycling was repeated following sectioning of the structure of interest (group 1, AN; group 2, LCL; and group 3, MCL). Torque at -12 degrees (pronation) and +18 degrees (supination) was measured for each intact and experimentally sectioned limb. A Student t test was performed to compare torque values obtained from intact verses experimentally sectioned limbs and for comparison with established criteria for differentiation of primary (> or = 33%), secondary (10 to 33%), and tertiary rotational stabilizers (< 10%). RESULTS: In pronation, the AN was the only primary stabilizer (65%). For supination, the LCL was a primary stabilizer (48%), AN was a secondary stabilizer (24%), and MCL was a tertiary stabilizer (7%). CONCLUSIONS AND CLINICAL RELEVANCE: With the elbow joint in extension at an angle of 135 degrees, the AN is a primary rotational stabilizer in pronation, and the LCL is a primary stabilizer in supination. Disruption of the AN or LCL may affect rotary range of motion or compromise stability of the elbow joint in dogs. 相似文献
17.
Samii VF Les Clifford M Schulz KS Keyak JH Stover SM 《American journal of veterinary research》2002,63(8):1159-1166
OBJECTIVE: To evaluate subchondral bone density patterns in elbow joints of clinically normal dogs by use of computed tomographic (CT) osteoabsorptiometry. SAMPLE POPULATION: 20 cadaver forelimbs from 10 clinically normal dogs. PROCEDURE: Each elbow joint was imaged in parasagittal and transverse planes of 1.5-mm thickness. Slice data were converted to dipotassium phosphate equivalent density (PPED) values. Sagittal, parasagittal, and transverse medial coronoid process topographic maps were constructed. Defined zones were created for each of the 3 CT planes, and confluence and peak PPED values were determined. RESULTS: The lowest PPED value was 340 mg/ml (articular and subchondral confluence), and the highest was 1780 mg/ml (peak subchondral density). Detectable effects of joint laterality were not found in the confluence or peak PPED measurements or in the peak-to-confluence PPED ratio for all 3 CT planes. Significant differences were found among zones in all 3 planes for confluence and peak PPED measurements and between sagittal and transverse planes for peak-to-confluence PPED ratios. Subjectively, the pattern of density distribution among dogs was fairly consistent for the sagittal and parasagittal slices. Three specific patterns of density distribution were apparent on the transverse topographic maps of the medial coronoid process that corresponded to conformational differences. CONCLUSIONS AND CLINICAL RELEVANCE: The use of CT osteoabsorptiometry provides a repeatable technique that can be used to noninvasively examine bone density and the effects of stress acting on joints in vivo. Variability in density values for any of the CT planes was not identified among clinically normal dogs. 相似文献
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19.
Zimmerman KL Bender HS Boon GD Prater MR Thorn CE Prater D Robertson JL Saunders GK Sponenberg DP Inzana KD Lanz OI Wright E 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2000,29(1):29-34
Abstract: The cytologic and histologic features of 2 intracranial and 2 spinal (extramedullary cervical) canine meningiomas were compared. Cerebrospinal fluid analysis in 2 cases revealed mild, mixed cell pleocytosis, primarily composed of small lymphocytes and monocytoid cells, with a moderate increase in total protein concentration. Cytologic features suggestive of meningioma included cells with both epithelial and mes-enchymal characteristics and a tendency towards cell clustering. Tumor location also was useful in making a diagnosis. The 4 meningiomas differed histologically from one another, and included angioblastic, psam-momatous, meningotheliomatous, and microcystic anaplastic types, which conformed to a classification scheme for human meningiomas. The classification scheme could not be applied to cytologic specimens. 相似文献
20.
Kurt A.Zuelke 《中国家禽》2007,29(20):30-31
美国农业部目前在依阿华州艾姆斯已完成了其动物卫生研究、诊断及动物产品检验设施的全面的、现代化的重建,共投入4.6亿美元,成为有史以来的美国农业部最大的建设项目.…… 相似文献