Genetic analysis of association among juvenile growth and female reproductive traits in Canadian Angus cattle
Bibliographic record
Abstract
The purpose ofthis research was to determine the genetic association between juvenile growth and female reproductive efficiency traits in beef cattle.Analyses ofthree data sets of calving records from 1984 to 2001 in five Angus herds were based on REML type mixed model methodology using a four trait model (n=6,886 animals in the pedigree, Study I) for birth weight (BW), weaning weight (WW), yearling weight ()'W) and firsr calving date (CD1), a five trait model (n=7,171, Study tr) for BW, WW, YW, calving date (CD) and calving interval (CI), and single trait models (n=6,864, Study III) for BW, WW and YW and stayability of cows to three years of age (Stay3, a binomial trait).The results from fourand five trait animal models revealed that the estimates of direct heritability (h'1) for BW, WW and YW were ranged from 0.44 to 0.80 (Study I and II), and that for WW and YW in the Study III were relatively lower.The maternal heritability (m'?) estimates for BW, WW and YW in all three studies were between 0.10 and 0.25.The h2 estimates of CD1 (Study I), CD and CI (Study tr) were 0.16, 0.25 and 0.10, respectively.The estimates of genetic comelations, both direcr (r,) and maternal (r",), among growth traits were positive and of a moderate to high magnitude (Study I and II).Direct-matenÌal genetic correlation (r"",) of each of the juvenile growth traits was negative indicating the antagonistic genetic relationship between animal's genetic porential for the trait and that for the mothering ability for the same trait (Study I and II).The r, estimate between CDl and WW was 0.27, indicating their unfavorable genetic association, while the conesponding estimates between BW and CD1, and between YW and CDI were negligible.The ru estimates of BW, WW and YW with CD were -0.19, -0.31 and -0.21, respectively, and those with CI were -0.23, -0.38 and -0.65, respectively, ìndicating their favorable genetic relationships.The r,, estimates of trait CD with matemal genetic effects for BW, WW and YW we¡e -0.02, -0.18 and -0.36, respectively.In contrast, the ru.estimates of CI with matemal genetic effects for BW and WW were zero and O.O7 , respectively.Conesponding estimate between Cl and maternal genetic effects for YW was 0.51, and possibly not consequential due to low heritabilities ofboth the traits.The results from the analyses of genetic trends (Study II) suggested that multiple traits played a role in the selection process.The culling rate ofcows in their herds as indicated by their hazard function was highest at three years of age, and heritablity for Stay3 was 0.38, demonstrating merit in genetic improvement.However, the EBVs for Stay3 were not significantly correlated with the direct or maternal EBVs fol any of the three growth traits studied, except that mate¡nal EBVs for WW and direct EBVs for Stay3 were positively correlated (P<0.10).
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".