Viability assessment of spermatozoa in large falcons (Falco spp.) using various staining protocols.

Viability assessment is an important part of semen analysis, and various live/dead staining protocols have been used in semen of avian species. Results of live/dead count differed between dyes, staining protocols and bird species, impeding comparability between studies and requiring species-specific comparisons of viability stains. In raptor semen, similar comparisons are absent. Thus, the aim of the present study was to compare eight conventional viability stains. Eosin blue 2% [EB], eosin blue 2% with the addition of 3% sodium citrate [EB2], eosin blue-nigrosin 5% [EBN5], eosin yellow-nigrosin 5% [EYN5], eosin yellow-nigrosin 10% [EYN10], eosin blue-aniline blue [EBA], eosin yellow-aniline blue [EYA] and bromophenol blue-nigrosin [BBN] were evaluated in comparison with the fluorescence stain SYBR® Green-propidium iodide [SYBR-PI] in spermatozoa of falcons. The comparison was performed using conventional light microscopy which is applicable in breeding centres, veterinary practices and field studies. Additionally, live/dead stains were correlated to motility values of the same samples to validate sperm viability. Light microscopy using EB and using SYBR-PI enabled an effective and clear differentiation between alive and dead spermatozoa of falcons. Motility values correlated significantly and strongly with EB only (r = .629; p < .001), but not with any other stain used in the study. Therefore, our results suggest EB as the most suitable stain for viability assessment in the semen of large falcons.

Quantitative assessment of German Holstein dairy cattle colostrum and impact of thermal treatment on quality of colostrum viscosity and immunoglobulins.

OBJECTIVE: This study aimed to determine the color, fat, viscosity, IgG concentration, %Brix and refractive index of fresh postpartum colostrum of German Holstein dairy cattle and assess the impact of different thermal treatments on the visual and dynamic viscosity, in association to IgG concentration, of colostrum that can be used for pasteurization process. RESULTS: Of the total 40 fresh postpartum colostrum, the color of colostrum (ranging from white-pale yellow to yellow and dark-yellowish), fat (1.4-8.2 100 g-1), IgG (4-116 mg mL-1), %Brix (8.5-35.4%), refractive index (1.3454-1.3905 nD), visual (ranging from watery to liquid and thick) and dynamic (4.9-219 cp) viscosity, were recorded. Statistical analysis between visual and dynamic viscosity of fresh colostrum showed significant correlation coefficients (rs = 634). Moreover, a significant correlation between viscosity and three IgG concentrations was also observed. Heat-treated colostrum showed dynamic viscosity ranged from 25 to 3066 cP, where dynamic viscosity of colostrum before- and after heat-treatment showed no significant correlation. Treated colostrum at 60 °C/60 min and 63.5 °C/30 min containing IgG concentration ≤ 80 mg mL-1 and ≤ 68 mg mL-1 showed no significant change in the viscosity and can successfully be applied for pasteurization of first postpartum colostrum.

[Measurement of IgG concentration in bovine colostrum by immunoturbidimetric assay in comparison to ELISA-based assessment]. / Messung der IgG-Konzentration in Rinderkolostrum mit einem immunturbidimetrischen Schnelltest im Vergleich zum ELISA.

OBJECTIVE: The aim of the presented study was to compare the results of IgG measurements using a turbidimetric immunoassay (TIA), a newly developed laboratory-independent method for direct immunoglobulin determination in colostrum, with measurements obtained via enzyme-linked immunosorbent assay (ELISA). MATERIAL AND METHODS: In colostrum samples from 59 cows, IgG concentration was measured using TIA and ELISA. RESULTS: Correlation analysis according to Pearson revealed a correlation coefficient of r = 0.74 (p < 0.0001) between the 2 methods. The Bland-Altman analysis showed that measurement by TIA resulted in significantly lower mean IgG levels than the ELISA-based quantification. This difference was more pronounced in high IgG concentration ranges. By means of a double-logarithmized data transformation it was calculated that the TIA-determined IgG-values on average amounted to 66.4 % of the IgG-values measured by ELISA. Although colostrum with low IgG concentration could be quantified with satisfactory reliability (sensitivity 100 %), high-quality colostrum was not sufficiently assessed in the TIA-based IgG measurements (specificity 40.4 %). CONCLUSION AND CLINICAL RELEVANCE: Based on the results of the presented study, IgG measurement by TIA cannot be recommended. In comparison to ELISA-based assessment, this technique does not exhibit higher correlations than established indirect rapid evaluation methods (density and viscosity determination).

Magnetic Resonance Imaging Assessment of Intra-Articular Structures in the Canine Stifle Joint after Implantation of a Titanium Tibial Plateau Levelling Osteotomy Plate.

OBJECTIVES: To determine the effectiveness of magnetic resonance imaging (MRI) in the evaluation of anatomical stifle structures with respect to implant positioning after tibial plateau levelling osteotomy (TPLO) using a titanium plate. METHODS: Selected sagittal and dorsal sequences of pre- and postoperative MRI (1.0 T scanner) of 13 paired (n = 26) sound cadaveric stifle joints were evaluated. The effect of susceptibility artifact on adjacent anatomical stifle structures was graded from 0 to 5. The impact of implant positioning regarding assessment score was calculated using Spearman's rank correlation coefficient. RESULTS: Sagittal turbo spin echo (TSE)-acquired images enabled interpretation of most soft tissue, osseous and cartilage structures without detrimental effect of susceptibility artifact distortions. In T2-weighted TSE images, the cranial cruciate ligament and caudal horn of the medial meniscus could be evaluated, independent of implant position, without any susceptibility artifact in all specimens. T2-weighted fast field echo, water selective, balanced fast field echo and short tau inversion recovery were most markedly affected by susceptibility artifact. CLINICAL SIGNIFICANCE: In selected TSE sequences, MRI allows evaluation of critical intra-articular structures after titanium TPLO plate implantation. Further investigations with confirmed stifle pathologies in dogs are required, to evaluate the accuracy of MRI after TPLO in clinical cases in this context.