12prediction of Bull Fertility by Computer Assisted Semen Analysis

Abstract

We developed a method to evaluate bovine sperm membranes in normal (1G) and simulated microgravity (Sim-µG). Bovine spermatozoa are used as a model system because they have cellular membranes analogous to those of other cell types, and yet are much simpler because they have no cytoplasm and do not participate in DNA transcription or mRNA translation. They can be cultured as single cells and are easily evaluated for membrane characteristics using flow cytometry. These features make the mammalian spermatozoon a useful model for exploring the principles of membrane structure/function in the presence of a variety of environmental challenges such as simulated microgravity. Cryopreserved, washed beef bull sperm (4-8 × 106 mL −1 ) were incubated under non-capacitating conditions (modified glucose-free Tyrode's medium containing low bicarbonate, HEPES buffer, pyruvate and 3 mg mL −1 BSA V; 23 • C in air), and these spermatozoa remained alive for 24-48 h at 1G. To simulate µG, spermatozoa were incubated under the same conditions, in a HARV 10 rotating wall vessel (RWV, Synthecon, Inc, Houston,TX, USA) at 9 rpms. Spermatozoa were incubated in 1G and Sim-µG environments for 2.5-4.5 h and subsequently exposed to 0, 60 or 80 µg mL For further statistical analysis, and incorporation of non-parametric statistical tools (including pattern recognition using Support Vector Machines), the data were processed using a collection of Perl scripts and C programs. Results: Live/dead status: When Sim-µG + 60 µg mL −1 LC sperm were compared to 1G + 60 µg mL −1 LC, and 80 µg mL −1 LC sperm, their profiles were more similar to the 1G 80 µg mL −1 LC profiles. AR status: the Sim-µG + 60 µg mL −1 LC profiles were similar to the 1G + 60 µg mL −1 LC profiles. Mitochondrial Status: the Sim-µG + 60 µg mL −1 LC profiles were more similar to 1G + 80 µg mL −1 LC profiles. Summary: although Sim-µG sperm lost their motility within 3 h, they were alive. Cell profiles indicate that Sim-µG sperm nuclear membranes are less stable and their mitochondria are less functional than the 1G controls, but their acrosomes are intact indicating that fertilizing potential may remain. Additional experiments are needed to determine the time course for Sim-µG, induced changes, and whether Sim-µG sperm can penetrate eggs.

Evaluation of motility, membrane status and DNA integrity of frozen–thawed bottlenose dolphin (Tursiops truncatus) spermatozoa after sex-sorting and recryopreservation

“…In cattle, several sperm velocity parameters have been shown to be positively associated with fertility rates (Cseh et al 2004, Gillan et al 2008. In the present research, FSF spermatozoa frozen with the DF method displayed higher velocities (VAP, VSL, VCL) at the majority of time points during the 24-h post-thaw incubation than Control spermatozoa frozen with the straw or DF method.…”

Effects of season on bull sperm quality in thawed samples in northern Spain

“…However, there is controversy about which particular sperm kinematic could best predict bull fertility (Pepper‐Yowell 2011, Simonik and others 2015). Cseh and others (2004) found that velocity parameters such as VAP, VCL and VSL from frozen‐thawed bull sperm samples had high correlations with non‐return rates (fertility rates), VAP being the one with highest correlation, whereas Nagy and others (2015) reported that VAP values could be a potential predictor of bull fertility. However, Gillan and others (2008) demonstrated that only VSL in post‐thaw samples was correlated with fertility rates.…”

Cattle Sperm Classification Using Transfer Learning Models

“…In modern years, science progressed rapidly mainly in computer and video processing; therefore, the functionality and accuracy of CASA system's latest versions are dramatically enhanced and provide more knowledge on the different sperm movement characteristics. Due to the sperm motility 's key role in the reproductive cycle, theses systems have capability to allow us to enter a new diagnostic andrological age and predict the semen's ability to fertilize [6].…”