Genetic analysis of test days, 305 days and lifetime lactation records in Sahiwal cattle
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Authors
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Manjari Pandey
Ph.D scholar Animal Genetics and breeding division, Indian Veterinary Research Institute, Izatnagar, Bareilly, U.P India
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Raja K N
Sr. Scientist, AG&B Division, ICAR- National Bureau of Animal Genetic Resources, Karnal, Haryana - 132001
Keywords:
First lactation 305day milk yield, Genetic correlation, Heritability, Lifetime milk yield, Phenotypic correlation, Sahiwal cattle, Test day milk yieldAbstract
The present research was aimed to perform genetic analysis of first lactation monthly test day milk yields, first lactation 305 days and lifetime milk yield of Sahiwal cattle. Data were collected on 867 Sahiwal cows sired by 76 bulls over a period of 31 years. Complete genetic analysis of all the traits was done using Harvey (model 2). The heritability of MTDMY ranged from 0.12 ± 0.06 (TD10) to 0.48 ± 0.09 (TD4) by LSML. The heritability estimates for FL305DMY and LTMY were found to be 0.40 ± 0.09 and 0.34 ± 0.07 respectively. The estimates of phenotypic and genetic correlation among all the monthly test day milk yields ranged from 0.14 to 0.79 and 0.15 to 0.99 respectively. The genetic correlation of MTDMY and FL305DMY ranged from 0.66 (TD1) to 0.99 (TD7, TD10).The phenotypic correlation of MTDMY with FL305DMY ranged from 0.29±0.04 (TD1) to 0.74±0.03 (TD6). The knowledge of the heritabilities and correlations among the traits help in developing the prediction models for performance traits which assists in developing better, accurate and faster selection strategies for breeding programs.
