GENETIC TRENDS IN ESTIMATED TRANSMITTING ABILITY FOR YIELD TRAITS OF SIRES BASED ON FIRST LACTATION | ||||
| Journal of Animal and Poultry Production | ||||
| Article 7, Volume 27, Issue 12, December 2002, Page 8195-8204 PDF (589.67 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jappmu.2002.257647 | ||||
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| Author | ||||
| H. G. El-Awady, | ||||
| Animal Production Department, Faculty of Agriculture Kafr El-Sheikh, Tanta University, Egypt | ||||
| Abstract | ||||
| A total of 10836 first lactation records German Friesian cows daughters of 781 sires, from 1979 to 1996 were used to study genetic progress achieved by predicted transmitting ability of sires (PTA) for 305 day milk yield (305dMY), milk fat (MF) and milk protein (MP). Data analyzed by using a multitrait REML with the animal model. Genetic variances were based on variation in estimated PTA values of individual sires. Also, regression methods to estimate the annual genetic progress were used. Heritabilities were 0.32, 0.36 and 0.31 for 305dMY, MF and MP, respectively. Genetic and phenotypic correlations among traits studied were positive and significant. PTA values for 305dMY ranged from –1984 to 1781 kg with average differences between sires of 3765 kg, as well as for MF ranged from –181.2 to 158.8 kg with average of 340 kg, and for MP ranged from –107.5 to 317.3 kg with average of 424.8 kg. Annual genetic change in the PTA for 305dMY, MF and MP averaged 222.11, 3.93 and 7.44 kg, respectively. The results indicated that the use of top ranking bulls on the basis of their PTA's for milk yield traits in breeding program will lead to noticeable genetic improvement in productivity of Friesian cows in Northern Germany. | ||||
| Keywords | ||||
| Heritability; Genetic; Phenotypic correlation; Genetic Trend; Predicted Transmitting Ability (PTA); Annual Genetic Change and German Friesian Cows | ||||
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