Ethiopian Institute of Agricultural Research, Holetta Agricultural Research Center, Addis Ababa or Holetta, Ethiopia
*Corresponding author: K Getahun; E-email: kefalegetahun@gmail.com
Online Published on 27 December, 2023.
Genetic and phenotypic correlations for reproductive and milk production traits were estimated by multitrait analysis of WOMBAT software. Total of 14222 crossbred dairy cows performance records collected from Holetta dairy research farm span over 43 years (1974-2017) were used for this study. Five reproductive; age at first calving (AFC), age at first service (AFS), calving interval (CI), days open (DO) and number of service per conception (NSC) and three-milk production; lactation milk yield (LMY), daily milk yield (DMY) and lactation length (LL) traits were included for estimation. The result of present study revealed that the genetic correlations among reproductive traits were varied from -0.31±0.08 to 0.98±0.03 while phenotypic correlations were ranged from -0.03±0.001 to 0.84±0.04. Strong positive genetic and phenotypic correlations were found between AFS and AFC traits (0.98±0.03) and (0.84±0.04), respectively. For milk production traits, the genetic correlations were ranged from 0.11±0.03 to 0.77±0.12 while phenotypic correlations were in the lower range of 0.07±0.02 to 0.36±0.07. Higher genetic correlations were observed between LMY and LL (0.77±0.12). The genetic correlations among reproductive and milk production traits were also varied from -0.55±0.04 to 0.79±0.07 while phenotypic correlations were ranged from -0.55±0.22 to 0.32±0.10. The higher genetic correlation was between CI and LL (0.79±0.07). The correlation between DMY and AFC (0.32±0.10) was recorded as higher phenotypically. The positive genetic correlations among traits indicates that effective selection of one trait might be improved the other and would be given the chance of broader selection of traits in the breeding goal. Therefore, to improve genetic progress and breeding efficiency of crossbred dairy cows in the research farm, estimation and selection of correlated traits should be done periodically.
• Milk yield and reproductive traits are complex relationship.
• This relationship can be depend on genetic and environmental variabilities.
• This study was conducted to know the correlation among reproductive and milk production traits and the results are summarized in this paper.
Crossbred, Genetic Correlation, Lactation Milk Yield, Phenotypic Correlation, Reproductive Trait
