Comparison of models for estimation of genetic parameters for mature weight of Hereford cattle
| Autor: | J. M. Rumph, L. D. Van Vleck, Larry V. Cundiff, R. M. Koch, K. E. Gregory |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Male
Weaning Breeding Biology Beef cattle Genetic correlation Animal science Genetics medicine Animals Selection (genetic algorithm) Models Statistical Models Genetic Body Weight Maternal effect General Medicine Quantitative genetics Heritability Trait Cattle Female Animal Science and Zoology Seasons medicine.symptom Weight gain Food Science |
| Zdroj: | Journal of Animal Science. 80:583-590 |
| ISSN: | 1525-3163 0021-8812 |
| DOI: | 10.2527/2002.803583x |
| Popis: | Genetic parameters of mature weight are needed for effective selection and genetic evalua- tion. Data for estimating these parameters were col- lected from 1963 to 1985 and consisted of 32,018 mature weight records of 4,175 Hereford cows that were in one control and three selection lines that had been selected for weaning weight, for yearling weight, or for an index combining yearling weight and muscle score for 22 yr. Several models and subsets of the data were considered. The mature weight records consisted of a maximum of three seasonal weights taken each year, at brand clipping (February and March), before breeding (May and June), and at palpation (August and September). Heritability estimates were high (0.49 to 0.86) for all models considered, which suggests that selection to change mature weight could be effective. The model that best fit the data included maternal genetic and maternal permanent environmental effects in addition to direct genetic and direct permanent environmental effects. Estimates of direct heritability with this model ranged from 0.53 to 0.79, estimates of maternal herita- bility ranged from 0.09 to 0.21, and estimates of the genetic correlation between direct and maternal effects ranged from −0.16 to −0.67 for subsets of the data based on time of year that mature weight was measured. For the same subsets, estimates of the proportions of vari- ance due to direct permanent environment and mater- nal permanent environment ranged from 0.00 to 0.09 and 0.00 to 0.06, respectively. Using a similar model that combined all records and included an added fixed effect of season of measurement of mature weight, di- rect heritability, maternal heritability, genetic correla- tion between direct and maternal effects, proportion of variance due to direct permanent environmental ef- fects, and proportion of variance due to maternal per- manent environmental effects were estimated to be 0.69, 0.13, −0.65, 0.00, and 0.04, respectively. Mature weight is a highly heritable trait that could be included in selection programs and maternal effects should not be ignored when analyzing mature weight data. |
| Databáze: | OpenAIRE |
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