Supplementation of freezing medium with encapsulated or free glutathione during cryopreservation of bull sperm
Bibliographic record
Abstract
Abstract The objective was to compare effects of encapsulated or free glutathione (GSH) on the quality of frozen‐thawed bull sperm. Ejaculates were collected via artificial vagina from six mature Holstein bulls once weekly for 6 weeks. All ejaculates had motility ≥70%, sperm concentration ≥1.0 × 10 9 /ml and ≤15% morphologically abnormal sperm. Each week, semen was pooled and diluted with lecithin‐based extenders containing various concentrations of encapsulated (E0, E1, E2.5 and E5 mM) or free (F0, F1, F2.5 and F5 mM) GSH, with total glutathione content determined before and after cryopreservation. Total GSH in fresh semen was (mean+ SEM ) 4.8 ± 0.2 nmol/10 8 sperm, whereas in frozen‐thawed semen of group F0 (control), it decreased to 1.4 ± 0.2 nmol/10 8 sperm, a 70.8% reduction ( p < .05). In addition, total GSH in frozen‐thawed semen from groups E2.5, E5 and F5 were 2.4 ± 0.2, 2.8 ± 0.2 and 1.8 ± 0.2 nmol/10 8 sperm, respectively (E5 versus. F0, p < .05). Compared to group F0, frozen‐thawed sperm from group E2.5 had greater ( p < .05) percentages of sperm that were viable (Annexin‐V) (61.1 ± 1.8 versus. 71.1 ± 1.8) and that had cell membrane integrity (eosin‐nigrosin) (64.5 ± 3.1 versus. 80.0 ± 3.1). Furthermore, frozen‐thawed sperm from group E2.5 had the numerically highest total and progressive motility (CASA) and cell membrane functionality (HOS) and the lowest percentage of early apoptotic sperm (Annexin‐V). However, acrosome membrane integrity (PSA) of E5 had the lowest mean ( p < .05), whereas E2.5 caused a small nonsignificant decrease (69.1 ± 1.4%) compared to E0 and F0. In conclusion, 2.5 mM encapsulated GSH in semen extender significantly improved the quality of frozen‐thawed bull sperm.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".