Cryopreservation of whole bovine ovaries: comparisons of different thawing protocols.

OBJECTIVE: The aim of this study was to perform a comparative investigation of several different thawing protocols and to determine an appropriate protocol for thawing whole bovine frozen ovaries. STUDY DESIGN: Bovine ovaries were slowly frozen and then thawed by applying different protocols. Ultrastructural change, follicle viability, and the hormone levels of culture supernatant were measured. RESULTS: The percentage of morphologically normal primordial follicles and the hormone levels of culture supernatant in group D (two-step, thawing in water at 39°C) were significantly higher than those in any other group. Moreover, the ultrastructural alteration of oocyte in group D (two-step, thawing in water at 39°C) was slighter than those in any other group. CONCLUSIONS: The two-step protocol involving short-term exposure to water at a moderately high temperature (39°C) proved to be a suitable for thawing bovine whole ovaries.

[The Near Infrared Spectral Bands Optimal Selection in the Application of Liquor Fermented Grains Composition Analysis].

In order to improve the technical level of the rapid detection of liquor fermented grains, in this paper, use near infrared spectroscopy technology to quantitative analysis moisture, starch, acidity and alcohol of liquor fermented grains. Using CARS, iPLS and no information variable elimination method (UVE), realize the characteristics of spectral band selection. And use the multiple scattering correction (MSC), derivative and standard normal variable transformation (SNV) pretreatment method to optimize the models. Establish models of quantitative analysis of fermented grains by PLS, and in order to select the best modeling method, using R2, RMSEP and optimal number of main factors to evaluate models. The results showed that the band selection is vital to optimize the model and CARS is the best optimization of the most significant effect. The calculation results showed that R2 of moisture, starch, acidity and alcohol were 0.885, 0.915, 0.951, 0.885 respectively and RMSEP of moisture, starch, acidity and alcohol were 0.630, 0.519, 0.228, 0.234 respectively. After optimization, the model prediction effect is good, the models can satisfy the requirement of the rapid detection of liquor fermented grains, which has certain reference value in the practical.