Estimation of Heritability for Somatic Cell Score of Holstein Cows in Hokkaido

2006 ◽  
Vol 77 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Shinya MIURA ◽  
Mitsuyoshi SUZUKI
Keyword(s):  
Somatic Cell ◽  
Somatic Cell Score ◽  
Holstein Cows

scholarly journals Heritability and repeatability of milk lactose and its relationships with traditional milk traits, somatic cell score and freezing point in Holstein cows

animal ◽  
2019 ◽  
Vol 13 (5) ◽  
pp. 909-916 ◽  
Author(s):  
A. Costa ◽  
N. Lopez-Villalobos ◽  
G. Visentin ◽  
M. De Marchi ◽  
M. Cassandro ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Freezing Point ◽  
Somatic Cell Score ◽  
Holstein Cows ◽  
Milk Traits

Relationship between somatic cell score and longevity of Holstein cows in Brazil using a piecewise Weibull proportional-hazard model

2019 ◽  
Vol 59 (8) ◽  
pp. 1546
Author(s):  
Elisandra Lurdes Kern ◽  
Jaime Araujo Cobuci ◽  
José Braccini Neto ◽  
Darlene dos Santos Daltro
Keyword(s):  
Somatic Cell ◽  
Milk Production ◽  
Hazard Model ◽  
Somatic Cell Score ◽  
Holstein Cows ◽  
Independent Effect ◽  
Proportional Hazard ◽  
Proportional Hazard Model ◽  
Weibull Proportional Hazard ◽  
The Impact

The objective of the present work was to evaluate the effect of somatic cell score on the longevity of Holstein cows raised all over Brazil, using a piecewise Weibull proportional-hazard model. The following two longevity traits were defined: true longevity, number of days from first calving to culling; and functional longevity, approximated by correcting true longevity to within-herd-year production. Records on productive life of 131330 cows were used. The model included the time-independent effect of age at first calving. The other effects were time-dependent, and included the following: region by year of calving, variation in herd-size class, milk-production class by year of calving within herd, within-herd milk-production class by number of lactations, within-herd fat content, within-herd protein content, and somatic cell score (SCS). The overall mean of the somatic cell counts (SCC) was 322000 cells/mL. The highest SCC mean was found between 130 to 290 days of lactation. The SCC mean decreased over the years. Cows from Region 5 (Rio Grande do Sul) showed higher SCC means. The risk of culling was slightly higher for functional longevity than for true longevity. The impact of longevity was high in cows from first to fourth lactation with a high SCS, with the risk of culling varying from 0.90 (true longevity: second lactation and Class 2) to 1.2 (functional longevity: fourth lactation and Class 5). Cows at the fifth lactation with a lower SCS had a higher risk of culling (1.4). Including the effect of SCS class by stage of lactation in the models was not beneficial. The decrease in SCS, especially from the first to fourth lactation, can be used for indirect selection to improve the longevity of Holstein cows in Brazil.

scholarly journals Effect of somatic cell count on milk fat and protein in different parities and stages of lactation in Holstein cows

2017 ◽  
Vol 110 (1) ◽  
pp. 37
Author(s):  
Arash CHEGINI ◽  
Navid GHAVI HOSSEIN-ZADEH ◽  
Hossein HOSSEINI-MOGHADAM ◽  
Abdol Ahad SHADPARVAR
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Milk Fat ◽  
Fixed Effects ◽  
Somatic Cell Count ◽  
Repeated Measurements ◽  
Somatic Cell Score ◽  
Holstein Cows ◽  
Dry Period ◽  
Protein Percentage

<p>The objective of this study was to investigate the effect of somatic cell score (SCS) on milk fat and protein in different parities and stages of lactation in Iranian Holstein cows. Records between June 2003 and January 2014 from 208,478 cows in lactations one to nine in 845 herds, comprising 2,456,303 monthly test-day (TD) records were used. The MIXED procedure of the SAS software with repeated measurements was used. The fixed effects of the model were herd, year-season of calving, month of TD, weeks of lactation, previous dry period length and somatic cell score (SCS) and covariate was calving age. Lactations were divided into six stages and analyses were performed within each stage. Also, different lactations were analyzed separately. Increase of SCS led to increase of milk fat and protein percentage and the increase of milk fat and protein associated with SCS was higher in early stages of lactation relative to later stages of lactation. Also, increase of milk fat and protein associated with SCS was higher in the first lactation rather than later lactations and decreased with increase of parity.</p>

Sign in / Sign up

Export Citation Format

Share Document