scholarly journals Joint estimation of genetic parameters for test-day somatic cell count and mastitis in the United Kingdom

2012 ◽  
Vol 95 (8) ◽  
pp. 4618-4628 ◽  
Author(s):  
R. Mrode ◽  
T. Pritchard ◽  
M. Coffey ◽  
E. Wall
Keyword(s):  
United Kingdom ◽  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Genetic Parameters ◽  
Joint Estimation ◽  
The United Kingdom ◽  
Estimation Of Genetic Parameters

Estimates of genetic parameters for test day somatic cell count fitting orthogonal polynomials

2001 ◽  
Vol 2001 ◽  
pp. 15-15
Author(s):  
R. A. Mrode ◽  
G. J. T. Swanson ◽  
C. M. Lindberg
Keyword(s):  
United Kingdom ◽  
Orthogonal Polynomials ◽  
Somatic Cell ◽  
Cell Count ◽  
Environmental Effects ◽  
Somatic Cell Count ◽  
Genetic Parameters ◽  
Random Regression ◽  
The United Kingdom ◽  
Genetic Evaluations

Genetic evaluations in the United Kingdom (UK) for Somatic Cell Count (SCC) are currently based on a single trait repeatability model using the first five lactations. Only cows with completed lactations are included. However, to utilise information from cows with part lactation records and to achieve a better correction for environmental effects, a test day model (TDM) evaluation would be preferred. The objective of this study is to estimate genetic parameters needed for such a TDM evaluation by utilising a random regression (RR) approach.

Relationship between linear and composite type traits, somatic cell count and lifespan in pedigree and non-pedigree cows

2002 ◽  
Vol 2002 ◽  
pp. 17-17
Author(s):  
R. A. Mrode ◽  
G. J. T. Swanson
Keyword(s):  
United Kingdom ◽  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Linear Type ◽  
The United Kingdom ◽  
Composite Type ◽  
Type Traits ◽  
The Relationship

Lifespan (LS) evaluations in the United Kingdom (UK) are based on bivariate analyses of LS scores, a direct longevity measure calculated from the number of lactations a cow has completed or is expected to complete, and an index of 4 linear type traits as an indirect predictor (Brotherstone et al, 1998). However, the study did not consider composite type traits or somatic cell count (SCC) and the data was only from pedigree herds. This study examines the relationship between type traits and SCC with LS in pedigree and non-pedigree cows.

scholarly journals Genetic Parameters for Somatic Cell Count, Logscc and Somatic Cell Score of Breeds: Improved Valachian, Tsigai, Lacaune and their Crosses/Genetski Parametri Za Broj Somatskih Ćelija, Logscc I Skor Somatskih Ćelija Kod Rasa: Poboljšana Vlaška, Cigaja, Lakon I Njihovih Meleza

2014 ◽  
Vol 64 (3) ◽  
pp. 386-396 ◽  
Author(s):  
Makovický Pavol ◽  
Makovický Peter ◽  
Nagy Melinda ◽  
Rimárová Kvetoslava ◽  
Diabelková Jana
Keyword(s):  
Animal Model ◽  
Maximum Likelihood ◽  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Genetic Parameters ◽  
Clinical Mastitis ◽  
Somatic Cell Score ◽  
Primary Data ◽  
Dairy Sheep

Abstract In the last few years there has been increasing emphasis on reducing milk somatic cell count to improve the milk quality in dairy ruminants. Genetic parameters for somatic cell count (SCC), LOGSCC and somatic cell score (SCS) were estimated. About 1193 measurements were included in the analysis for each character of 358 ewes of 9 genotypes. Nine breeds and genotypes were included in these experiments: purebred Improved Valachian (IV), Tsigai (T), Lacaune (LC) ewes, and IV and T crosses with a genetic portion of Lacaune and East Friesian (EF) - 25 %, 50 % and 75 %. Primary data were processed using restricted maximum likelihood (REML) methodology and the multi-trait animal model, using programs REMLF90 and VCE 4.0. Heritability coefficients for somatic cell count were low: h2=0.03, for LOGSCC h2= 0.08 and for somatic cell score h2=0.06. Somatic cell score can be considered for inclusion in a breeding program aimed at reducing somatic cell count and frequency of clinical mastitis in dairy sheep.

scholarly journals Genetic Parameters of Bovine Milk Fatty Acid Profile, Yield, Composition, Total and Differential Somatic Cell Count

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2406
Author(s):  
Tania Bobbo ◽  
Mauro Penasa ◽  
Martino Cassandro
Keyword(s):  
Animal Models ◽  
Somatic Cell ◽  
Cell Count ◽  
Milk Yield ◽  
Milk Fat ◽  
Fixed Effects ◽  
Somatic Cell Count ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Bovine Milk

The growing interest of consumers for milk and dairy products of high nutritional value has pushed researchers to evaluate the feasibility of including fatty acids (FA) in selection programs to modify milk fat profile and improve its nutritional quality. Therefore, the aim of this study was to estimate genetic parameters of FA profile predicted by mid-infrared spectroscopy, milk yield, composition, and total and differential somatic cell count. Edited data included 35,331 test-day records of 25,407 Italian Holstein cows from 652 herds. Variance components and heritability were estimated using single-trait repeatability animal models, whereas bivariate repeatability animal models were used to estimate genetic and phenotypic correlations between traits, including the fixed effects of stage of lactation, parity, and herd-test-date, and the random effects of additive genetic animal, cow permanent environment and the residual. Heritabilities and genetic correlations obtained in the present study reflected both the origins of FA (extracted from the blood or synthesized de novo by the mammary gland) and their grouping according to saturation or chain length. In addition, correlations among FA groups were in line with correlation among individual FA. Moderate negative genetic correlations between FA and milk yield and moderate to strong positive correlations with fat, protein, and casein percentages suggest that actual selection programs are currently affecting all FA groups, not only the desired ones (e.g., polyunsaturated FA). The absence of association with differential somatic cell count and the weak association with somatic cell score indicate that selection on FA profile would not affect selection on resistance to mastitis and vice versa. In conclusion, our findings suggest that genetic selection on FA content is feasible, as FA are variable and moderately heritable. Nevertheless, in the light of correlations with other milk traits estimated in this study, a clear breeding goal should first be established.

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