Generation-wise genetic evaluation of various first lactation traits and herd life in Karan Fries cattle*
2010
SAHA, SUJIT | JOSHI, B K | SINGH, AVTAR
The present study was based on the data collected on 3051 Karan Fries cows (1971–2000) maintained at the National Dairy Research Institute, Karnal. Pedigree of each animal born during this period was traced back up to foundation stock. Only 2741 Karan Fries animals had complete pedigree records. Paternal and maternal generations were determined separately. Cows up to fifth generation from paternal side and ninth generation from maternal side in Karan Fries were observed. The averages for first lactation traits, viz. FL305DMY, FLTMY, FLL, FSP, FDP, FCI, MY/FLL, MY/FCI were 2 470.35±80.75 kg, 2822.91±121.94 kg, 315.25±10.10 days, 127.69±11.27 days, 80.72±5.96 days, 423.20±13.17 days, 8.76±0.29 kg and 7.78±0.28 kg, and the average herd life (HL) was 1809.80±85.11 days. Generation-wise evaluation of the performance revealed that performance deteriorated after first generation. But from second generation onwards no definite trend was observed. Low to moderate heritability estimates were observed for various first lactation production, reproduction traits and herd life, while, relatively high estimate of heritability were observed for MY/FLL, MY/FCI. These high estimates of heritabiliy indicate that there is enough scope for improvement in these traits through selection. However, low to moderate heritability estimates for FDP, FLL, FLTMY, FL305DMY suggest that these traits can be improved through progeny testing and/or family selection. Improvement in managemental practices could also improve these traits. Positive estimate of phenotypic and genetic correlations between FL305DMY, FLTMY and FLL with FSP, FDP, FCI, MY/FLL, MY/FCI and HL, confirms high producing animals were generally poor with respect to reproduction traits but due to their high producing ability, animals were kept in the herd for longer periods
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Эту запись предоставил Indian Council of Agricultural Research
