scholarly journals Estimation of Genetic Parameters and Genetic Trends of Somatic Cell Score in Iranian Holsteins

2017 ◽  
Vol 8 (15) ◽  
pp. 201-209
Author(s):  
Hassan Khanzadeh ◽  
Navid Ghavi Hossein-Zadeh
Keyword(s):  
Somatic Cell ◽  
Genetic Parameters ◽  
Somatic Cell Score ◽  
Estimation Of Genetic Parameters ◽  
Genetic Trends

scholarly journals Estimation of Genetic Parameters for Test Day Records of Somatic Cell Score

1995 ◽  
Vol 78 (12) ◽  
pp. 2847-2857 ◽  
Author(s):  
R. Reents ◽  
J. Jamrozik ◽  
L.R. Schaeffer ◽  
J.C.M. Dekkers
Keyword(s):  
Somatic Cell ◽  
Genetic Parameters ◽  
Somatic Cell Score ◽  
Estimation Of Genetic Parameters

scholarly journals Estimation of Genetic Parameters for Somatic Cell Score in Holsteins

1992 ◽  
Vol 75 (8) ◽  
pp. 2265-2271 ◽  
Author(s):  
Y. Da ◽  
M. Grossman ◽  
I. Misztal ◽  
G.R. Wiggans
Keyword(s):  
Somatic Cell ◽  
Genetic Parameters ◽  
Somatic Cell Score ◽  
Estimation Of Genetic Parameters

scholarly journals Genetic parameters of test-day somatic cell scores for the first three lactations of Polish Holstein-Friesian cattle

2011 ◽  
Vol 56 (No. 9) ◽  
pp. 381-389 ◽  
Author(s):  
K. Rzewuska ◽  
J. Jamrozik ◽  
A. Żarnecki ◽  
T. Strabel
Keyword(s):  
Somatic Cell ◽  
Bayesian Methods ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Large Data ◽  
Somatic Cell Score ◽  
Data Set ◽  
Holstein Friesian ◽  
Covariance Components ◽  
Friesian Cattle

 Genetic parameters for somatic cell score in the first three lactations of Polish Holstein-Friesian cattle were estimated. A multiple-lactation model was applied with random herd-test-day effect, fixed regressions for herd-year and age-season of calving, and random regressions for the additive genetic and permanent environmental effects. The large data set was used that included over one million test-day records and more than 58 000 cows. Estimates of covariance components and genetic parameters were obtained by Bayesian methods using the Gibbs sampler. Average daily heritabilities of somatic cell score (SCS) in the first three lactations were 0.11, 0.12 and 0.14 for the first, second and third lactation, respectively. Estimates of daily heritabilities were rather independent of days in milk (DIM), with no serious abnormalities at the beginning or the end of lactation. Average genetic correlations between SCS on the same DIM were 0.68, 0.62 and 0.70 for first and second, first and third, and second and third parities, respectively, and did not exceed 0.77. The low level of heritability estimates and relatively low genetic correlations between lactations would suggest that selection based on the first lactation only could limit a response in mastitis resistance for later lactations.

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