Citation
Shadparvar A. A., . and Yazdanshenas M. S., . and Moradi Shahrebabak M., . and Mollasalehi M. R., . (2004) Estimation of genetic parameters for first lactation milk production test day records of Iranian Holstein cows. [Proceedings Paper]
Abstract
Genetic parameters for first lactation milk production based on 418480 test day records of 56319 Iranian Holstein cows that calved between 1991 and 2001 were estimated using a model. Heritability for test day yield was the highest in second half of the lactation ranging from 0.11 to 0.19. They were lower than previous estimates on Iranian Holstein cows and it seems that utilization of different models and accounting for non additive genetic effects in this study might be the main reason. Estimate for lactation record was 0.24. Genetic corretations between individual test days were high for consecutive test days 0.9 and decreased as the interval between tests increased. Estimate of genetic correlations of test day yield with lactation yield were hightest 0.78 to 0.86 for mid-lactation TD3 to TD8 and suggests that mid-lactation test day yields may be used for genetic evaluation instead of the 305-day yield.
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Abstract
Genetic parameters for first lactation milk production based on 418480 test day records of 56319 Iranian Holstein cows that calved between 1991 and 2001 were estimated using a model. Heritability for test day yield was the highest in second half of the lactation ranging from 0.11 to 0.19. They were lower than previous estimates on Iranian Holstein cows and it seems that utilization of different models and accounting for non additive genetic effects in this study might be the main reason. Estimate for lactation record was 0.24. Genetic corretations between individual test days were high for consecutive test days 0.9 and decreased as the interval between tests increased. Estimate of genetic correlations of test day yield with lactation yield were hightest 0.78 to 0.86 for mid-lactation TD3 to TD8 and suggests that mid-lactation test day yields may be used for genetic evaluation instead of the 305-day yield.
Additional Metadata
| Item Type: | Proceedings Paper |
|---|---|
| Additional Information: | Summary En |
| AGROVOC Term: | GENETIC PARAMETERS |
| AGROVOC Term: | COWS |
| AGROVOC Term: | HERITABILITY |
| AGROVOC Term: | MILK RECORDING |
| AGROVOC Term: | PERFORMANCE TESTING |
| AGROVOC Term: | MILK PERFORMANCE |
| AGROVOC Term: | ANIMAL PRODUCTION |
| AGROVOC Term: | LACTATION |
| AGROVOC Term: | LACTATION DURATION |
| AGROVOC Term: | MILK YIELD |
| Geographical Term: | MALAYSIA |
| Depositing User: | Ms. Norfaezah Khomsan |
| Last Modified: | 24 Apr 2025 05:27 |
| URI: | http://webagris.upm.edu.my/id/eprint/16352 |
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