The purpose of this study was to estimate the genetic and phenotypic parameters in order to obtain the trends of 305˗day milk yield (305˗DMY) lactation period (LP), calving interval (CI) and days open (DO) of Friesian cows. Data consisted of 5728 lactation records for 2040 Friesian cows sired by 139 bulls during the years from 1979 to 2016 at Sakha and El-Karada Farms inherent in the Animal Production Research Institute (APRI), Kafr-Elsheikh Governorate, Egypt. Data were analyzed using Harvey program statistic (Harvey, 1990) to determine the fixed effects to be included in the analytical model. Covariance components were estimated for univariate and bivariate analysis for all traits with derivative-free restricted maximum likelihood (REML) procedures using the MTDFREML program of Boldman et al., (1995). Means for 305-DMY, LP, CI and DO were 2632.09 kg, 300.02 d, 449.92 d and 173.95 d, respectively. Heritability estimates were 0.24, 0.22, 0.16 and 0.17 for the similar previous traits, subsequently. The genetic correlation between all traits studied were moderate and positive, ranging from 0.26 to 0.75. Corresponding phenotypic correlations between different traits under investigation were small and positive and ranged between 0.05 to 0.29. The annual genetic changes in the breeding values (BV's) were positive for 305-DMY (6.10 kg/yr.) while being negative for LP, CI and DO (-0.16, -0.05 and -.06 d/yr, respectively), indicating that there is an achievement superior sires however more attention should be given to reproductive traits to avoid losses related to these traits in the future. The results indicated that the use of top ranking bulls on the basis of their (BV's) for milk yield traits in breeding program will lead to noticeable genetic improvement in productivity of Friesian cows in Egypt.
El–Awady, H., Salem, A., Abdel-Glil, M., Zahed, S., & Abo El-Enin, A. (2017). Estimate of Genetic and Phenotypic Trends for Some Productive and Reproductive Traits of Friesian Cows in Egypt. Journal of Animal and Poultry Production, 8(8), 329-334. doi: 10.21608/jappmu.2017.45990
MLA
H. G. El–Awady; A. Y. Salem; M. F. Abdel-Glil; S. M. Zahed; A. Abo El-Enin. "Estimate of Genetic and Phenotypic Trends for Some Productive and Reproductive Traits of Friesian Cows in Egypt", Journal of Animal and Poultry Production, 8, 8, 2017, 329-334. doi: 10.21608/jappmu.2017.45990
HARVARD
El–Awady, H., Salem, A., Abdel-Glil, M., Zahed, S., Abo El-Enin, A. (2017). 'Estimate of Genetic and Phenotypic Trends for Some Productive and Reproductive Traits of Friesian Cows in Egypt', Journal of Animal and Poultry Production, 8(8), pp. 329-334. doi: 10.21608/jappmu.2017.45990
VANCOUVER
El–Awady, H., Salem, A., Abdel-Glil, M., Zahed, S., Abo El-Enin, A. Estimate of Genetic and Phenotypic Trends for Some Productive and Reproductive Traits of Friesian Cows in Egypt. Journal of Animal and Poultry Production, 2017; 8(8): 329-334. doi: 10.21608/jappmu.2017.45990
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