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Martin Hughes Victor Mlambo Cicero HO Lallo Paul GA Jennings 《African Journal of Range and Forage Science》2016,33(4):253-264
This study evaluated whether the FieldScout CM 1000 NDVI and Yara N–Tester models can produce accurate and reliable estimates of nitrogen (N), buffer-soluble nitrogen (BSN), buffer-insoluble nitrogen (BISN), non-protein nitrogen (NPN) and in vitro ruminal nitrogen degradability after 3, 12 and 24?h incubation (ND3, ND12 and ND24) in three tropical grasses: Brachiaria hybrid, Megathyrsus maximus and Paspalum atratum. Correlation between the Yara N-Tester and N, BISN and in vitro ruminal N degradability of the Brachiaria hybrid and M. maximus were high (r 0.67–0.83). The Yara N-Tester accounted for 81% and 86% (p 0.000) of N variability in the Brachiaria hybrid and M. maximus, respectively. The Yara N-Tester prediction models explained 72% and 70% (p 0.000) BISN variability in the Brachiaria hybrid and M. maximus, respectively. In vitro ND24 of the Brachiaria hybrid (R?2 0.75) and M. maximus (R?2 0.75) was also best predicted with the Yara N-Tester. Model validation showed generally low (≤0.90) concordance correlation coefficients except for Yara N-Tester N and ND24 in M. maximus. Random error was the main source of error. We conclude that the accuracy of the Yara N-Tester prediction models was superior to that of the FieldScout CM 1000 NDVI models, and that the Yara N-Tester can produce accurate and reliable estimates of Brachiaria hybrid and M. maximus N and M. maximus ND24. 相似文献
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R Mischke D Meurer H.-O Hoppen S Ueberschr M Hewicker-Trautwein 《Research in veterinary science》2002,73(3)
Oestradiol-17β and testosterone blood plasma concentrations were measured in dogs with Leydig-cell tumours (n=20), Sertoli-cell tumours (n=6), seminomas (n=9), unilateral inguinal cryptorchidism (n=7), abdominal cryptorchidism (n=9, one bilateral), degenerate scrotal testicles (n=6, two bilateral), and animals with normal scrotal testicles (n=20). The testosterone/oestradiol ratio (testosterone concentration [ng/mL] × 100/oestradiol concentration [pg/mL]) was calculated.A considerably higher oestradiol concentration was found in dogs with Sertoli-cell tumours (29.0, 14.4–48.3 pg/mL; median, minimum–maximum; P=0.0256, Mann–Whitney test) and lower oestradiol levels were found in animals with seminomas (12.0, 3.4–17.6 pg/mL; P=0.0025) compared to the healthy control group (18.0, 8.6–31.5 pg/mL). Testosterone concentration was decreased in dogs with Sertoli-cell tumours (0.08, 0.03–0.77 ng/mL) when compared to the control group (1.95, 0.05–3.70 ng/mL; P=0.0012). Testosterone/oestradiol ratios differed from the control (9.6, 0.58–35.8) only in dogs with Sertoli-cell tumours (0.32, 0.06–2.80; P=0.0005). Clinical signs of feminization were observed in five dogs with Sertoli-cell tumour and one dog with a Leydig-cell tumour, and were more often associated with decreased testosterone/oestradiol ratios than with an increased oestradiol-17β concentration. 相似文献
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Goehring C Aurich C Lange J Hoppen HO Aurich JE 《Tier?rztliche Praxis. Ausgabe G, Grosstiere/Nutztiere》1999,27(1):25-29
In this study, LH release in response to the GnRH agonist buserelin and during treatment with a progesterone-releasing intravaginal device (PRID) was studied. A dose of 20 micrograms buserelin induced a more pronounced LH release than 4, 8, 40 and 80 micrograms. After injection of buserelin, pituitary response to a second buserelin injection was markedly reduced for at least 24 hours. Repeated buserelin injections at an interval of several hours therefore cannot be recommended. LH release was markedly suppressed by treatment with PRID. Two PRID tended to be more effective than one. After PRID removal, LH release increased significantly. 相似文献
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NATASHA M. WERPY CHARLES P. HO CHRISTOPHER E. KAWCAK 《Veterinary radiology & ultrasound》2010,51(1):2-10
Distal forelimb specimens of eight skeletally mature horses were imaged using proton density turbo spin echo, T1-weighted spoiled gradient echo, T2* -weighted gradient echo, short tau inversion recovery and T2-weighted fast spin echo sequences with the limb parallel to the main magnetic field, and with angulation of the limb relative to the main magnetic field. The magic angle effect can be identified in the collateral ligaments of the distal interphalangeal joint when imaged in a high-field magnetic resonance (MR) imaging system with a horizontally oriented main magnetic field. This effect has previously been described in the collateral ligaments of the distal interphalangeal joint in a low-field system with a vertically oriented main magnetic field. The curvature of the ligaments places the fibers at the magic angle in both horizontally and vertically orientated main magnetic fields. This effect can be identified on short time of echo sequences and impacts the signal pattern of the ligaments at the level of the middle phalanx with the limb in a neutral position and with angulation of the limb. Magic angle effect should be considered as a possible cause of an asymmetrical signal pattern, depending on the positioning of the limb and the sequences used for imaging, when evaluating the collateral ligaments of the distal interphalangeal joint on images acquired with a high-field MR imaging system that has a horizontally oriented main magnetic field. 相似文献