Prevalence and Morphological Appearance of Sperm Nuclear Defects Using Feulgen Reaction in Beef Bulls
Bibliographic record
Abstract
The objective of this study was to assess the prevalence and compare the morphological aspects of sperm nuclei abnormalities in beef bulls submitted to breeding soundness evaluation (BSE). Semen samples were collected by electroejaculation from 649 beef bulls (Bos indicus, n = 515 and Bos indicus × Bos taurus crossbreed, n = 134) ranging from 2 to 12 years of age. Following a clinical evaluation and semen assessment, a slide was prepared with fresh semen and stained by using the Feulgen-stain for the purpose of evaluating sperm and nuclear morphology. Abnormal sperm nuclei were classified into three categories: A, multiple vacuoles in a pouch-like formation; B, a single vacuole such as the nuclear crater/diadem defect; and C, abnormal chromatin condensation. In accordance with the BSE criteria, the animals were classified as either satisfactory or unsatisfactory potential breeders. The prevalence of nuclear defects was comparable between satisfactory bulls of both genotypes. Unsatisfactory Bos indicus bulls exhibited a higher frequency of A and B nuclear defect categories. A category presented an odds ratio of 7.14 (0.012) for unsatisfactory bulls. A low percentage of the C category (2.3%) was observed in both BSE classifications. Vacuoles or craters were predominantly observed in the post-acrosomal and mid-subacrosomal regions, with minimal occurrence in the apical ridge region. Our findings provide the baseline for nuclear defects in B. indicus and its crossbreeds. The Feulgen reaction thus enables a simple yet comprehensive analysis of nuclear sperm head defects during BSE. In addition, stain retention facilitates a practical evaluation and an accurate account of the nuclear lesion types.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| 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) | 0.000 | 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 teacher head, 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".