Genetic Analysis of Days Open in Moroccan Holstein Cows
Author Information
Author(s): Chafai Narjice, Badaoui Bouabid, Davis Michael E.
Primary Institution: Mohammed V University in Rabat, Morocco; Mohammed VI Polytechnic University (UM6P), Morocco
Hypothesis
Can different models effectively handle censored data in the genetic evaluation of fertility traits in Moroccan Holstein cows?
Conclusion
The penalized threshold model showed slightly higher heritability compared to linear models, and both the penalty method and the threshold method had comparable predictive abilities.
Supporting Evidence
- The study found that 14.51% of the days open records were censored.
- Heritability estimates for days open ranged from 0.021 to 0.033 across different models.
- Both the penalty method and the threshold method showed similar predictive abilities.
Takeaway
This study looked at how to better understand the breeding of Holstein cows by using different methods to fill in missing data about how long it takes for them to get pregnant again after having a calf.
Methodology
The study used three methods: a linear model, a penalty method, and a threshold linear model with a penalty to analyze days open data from Holstein cows.
Potential Biases
Potential bias from removing censored data could compromise genetic evaluations.
Limitations
The dataset was limited and contained a high rate of censored records, which may affect the accuracy of genetic evaluations.
Participant Demographics
The study involved 6337 Holstein cows from four herds in northern Morocco.
Digital Object Identifier (DOI)
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