Age of dam and age at measurement adjustments and genetic parameters for scrotal circumference of Canadian Hereford bulls
Bibliographic record
Abstract
The objective of the study was to estimate age of dam and age at measurement as adjustment factors for scrotal circumference in Canadian Hereford bulls (n = 9029) and to estimate genetic parameters for scrotal circumference, and birth and yearling weights. Quadratic effects of age at measurement and the interaction of age of dam with age at measurement were not important. Adjustment factors recommended for yearling bulls were 1.02, 0.33, 0.10, and 0.16 cm to adjust scrotal circumference of sons of 2-, 3-, 4-, and ≥ 10-yr-old cows to a mature dam (5 to 9 yr of age) equivalent. The linear partial regression coefficient for age at measurement was 0.036 cm d-1. Genetic parameters were estimated using a multiple trait animal model and REML. The heritability estimate for (age of dam and age at measurement) adjusted scrotal circumference was 0.40 ± 0.03, and heritability estimates were 0.43 ± 0.05, 0.21 ± 0.09, and 0.36 ± 0.03 for direct birth weight, maternal birth weight, and yearling weight, respectively. The genetic correlation of adjusted scrotal circumference with direct birth weight was low (0.15), and was moderate (0.38) with yearling weight, but was near zero (-0.01) with maternal birth weight. Environmental and phenotypic correlations of adjusted scrotal circumference were low with birth weight, and were high with yearling weight. These results indicate that there was a positive association between adjusted scrotal circumference and body weight. Genetic improvement of fertility through the use of adjusted scrotal circumference as an indicator trait would not be expected to be antagonistic to that for body weight. Key words: Beef cattle, fertility, Hereford, scrotal circumference
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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 | 0.002 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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".