Prediction of scrotal circumference expected progeny differences in limousin cattle
Bibliographic record
Abstract
In the first phase, 557 Limousin bulls were placed on a Canadian \nLimousin Association postweaning gain test over 4 yr (1987 to 1991). \nBulls varied in age by 120 d. Weights (WT) and scrotal circumferences \n(SC) were collected at 28 d intervals from shortly after weaning to the end \nof the test on each bull (6 or 7 measurements per year). Hip heights (HT) \nwere collected on the second and again on the final measurement dates \neach year. Age in days (AGE) was calculated for each measurement date. \nAge of dam (AOD) was also recorded for each bull on test. Correlations of \nSC with AGE, WT and HT were high and positive (P < .0 1). Year and AOD \neffects were present (P < .001). Quadratic regression equations were \nestimated for AGE, WT and HT on SC to develop adjustment equations. \nThe resulting regression equation for the estimation of SC from AGE was: \nY = -3.02 + .131(AGE)- .000114(AGE)2 (R2 = 74.8°/o, P < .001). Age-ofdam \nadjustment factors were determined by use of indicator variables. \nAnalyses showed that age adjusted SC should be adjusted to a 4- to 10- \nyear AOD equivalent by adding .51, .31 or .36 em for dams 2, 3 or> 11 \nyears of age (P < .05). Adjustment of scrotal circumference in Limousin \nbulls to a constant, for subsequent use in national cattle evaluation, can \nbest be achieved by removing some of the variation in scrotal \ncircumference caused by environmental effects of age of dam and age, \nweight or height. \nNext, variance and covariance components were estimated for \nscrotal circumference and weaning weight from Limousin field data. \nRecords of 8,226 bulls were used to evaluate 590 sires and 661 maternal grand sires. Data included all herd book records of bulls with a recorded \nscrotal circumference and their weaning contemporaries. Analyses were \ncarried out by REML techniques employing the EM algorithm and fitting \nboth single- and two-trait models. Scrotal circumference was first fitted \nin a single-trait, sire model to obtain starting values for variances for a \nlater analysis. Likewise, weaning weight was fitted in a single-trait, sirematernal \ngrandsire model to obtain starting values for (co)variances for a \nlater analysis. Scrotal circumference and weaning weight were then \nfitted together in a two-trait model to estimate variance components. \nEstimates of variance components were calculated by equating \n(co)variances obtained from the models to their expectations. Estimates \nof heritability of scrotal circumference, direct weaning weight and \nmaternal weaning weight were .46, .25 and .19, respectively. Estimates \nof genetic correlations between scrotal circumference and direct weaning \nweight, scrotal circumference and maternal weaning weight, and direct \nweaning weight and maternal weaning weight were .14, -.22 and -.44, \nrespectively. The estimate of the environmental correlation between \nscrotal circumference and weaning weight was .59. \nFinally, the genetic parameters obtained were utilized to predict \nbreeding values. Records on 9,618 bulls were available for the prediction \nof breeding values. Two-trait, reduced animal mixed model equations for \na maternally influenced trait were utilized and solved by BLUP \nprocedures to predict the breeding values. A genetic trend in scrotal \ncircumference for animals born from 1971 to 1989 was not discernible in \nthese data.
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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 | 0.000 |
| 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 | 0.001 | 0.000 |
| Research integrity | 0.001 | 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".