Daughters’ Maternal Grandsires in Sire Evaluation
نویسندگان
چکیده
منابع مشابه
Effect of ignoring random sire and dam effects on estimates and standard errors of breed comparisons.
Data were weights of F1 calves and weaning weights of top-cross progeny from sires and maternal grandsires of 13 breeds. Three analyses were performed on each trait to obtain estimates and standard errors of breed effects needed to calculate across-breed EPD and accuracies. Model (R) for records of F1 progeny contained fixed effects for birth year and date of birth, sex, age and breed of dam, a...
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Correlations were computed among averages of first lactation deviations from herdmate averages of groups of artificially sired daughters of the same Holstein bulls. The groups were constructed by specifying the time interval between animals in the different groups. Comparison of the actual correlations with the expected correlations suggests that environmental correlations are small or nil amon...
متن کاملGenetic evaluation of stillbirth in United States Holsteins using a sire-maternal grandsire threshold model.
A sire-maternal grandsire threshold model was used for genetic evaluation of stillbirth in US Holsteins. Calving ease and stillbirth records for herds reporting at least 10 dead calves were extracted from the Animal Improvement Programs Laboratory database. About half of the 14 million calving ease records in the database had a known livability score, mostly from herds processed by Dairy Record...
متن کاملImplementation of a sire-maternal grandsire model for evaluation of calving ease in the United States.
The objective of this study was to add a maternal grandsire (MGS) effect to the existing sire model for national calving ease genetic evaluations. The Animal Improvement Programs Laboratory (AIPL) of USDA assumed responsibility for conducting the national genetic evaluation for calving ease and maintaining the associated database in 1999. Existing evaluations used a sire threshold model. Adding...
متن کاملA Cohort study evaluation of maternal PCB exposure related to time to pregnancy in daughters
BACKGROUND Polychlorinated biphenyls (PCBs) remain ubiquitous environmental contaminants. Developmental exposures are suspected to impact reproduction. Analysis of mixtures of PCBs may be problematic as components have a complex correlation structure, and along with limited sample sizes, standard regression strategies are problematic. We compared the results of a novel, empirical method to thos...
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ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 1979
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(79)83416-5