Genetic evaluation of clinical mastitis traits in Holstein cattle

To chci

The results obtained from different models for predicting breeding values for clinical mastitis (CM) in Holstein cattle were compared. CM was recorded in 30 882 lactations of 12 793 cows in 8 herds from 1996 to 2016. CM was considered either as an all-or-none binary trait (0 - absence of mastitis; 1 - at least one case of CM per lactation) or as the number of cases. CM is recorded in the first 150 days of lactation or throughout the entire course of lactation. Breeding values were predicted with a single-trait repeatability model and with a bivariate animal model, where CM during the 1st lactation and CM during the 2nd and later lactations were considered as two different traits. Estimated heritability ranged from 0.06 for CM as a 0/1 trait during the first 150 days of lactation in the repeatability model to 0.12 for the number of CM cases during the 1st lactation in the bivariate model. Ranking of the sires with 15 or more daughters and of the cows was performed according to their breeding values, and Spearman correlation coefficients were calculated. Rank correlations of breeding values from the repeatability and bivariate models were stronger for the same parts of lactation (150 vs 305 days; 0.88-0.96) and for the repeatability model and the bivariate model for the 2nd and later lactations (0.95-0.98). Trends of average male and female breeding values according to their birth year were used to assess genetic changes in the population. The average breeding values declined slowly for cows born since 2003 but stayed above neutral value, thus indicating permanent genetic deterioration of mastitis resistance. … celý popis

Podrobná bibliografie

Hlavní autor:

Eva Kašná

Další autoři:

Ludmila Zavadilová
Miloslava Štípková

Typ dokumentu:

Články

Publikováno v:

Czech Journal of Animal Science. -- ISSN 1212-1819. -- Roč. 63, č. 11 (2018), s. 443-451

Témata:

DAIRY CATTLE

DAIRY COWS

Udders

MAMMARY GLANDS

INFLAMMATION

BACTERIOSES

BOVINE MASTITIS

BREEDING VALUE

FATHERS

Dams (mothers)

DAUGHTERS

Dairy herds

STATISTICAL DATA

MILK PERFORMANCE

MILK YIELD

LACTATION NUMBER

PARTURITION

Seasonality

DATA ANALYSIS

POPULATION GENETICS

GENOTYPE ENVIRONMENT INTERACTION

Genetic improvement

TRENDS

FORECASTING

Impact assessment

MATHEMATICAL MODELS

mléčný skot

vemeno

mléčné žlázy

zánět

bakteriózy

mastitida skotu

šlechtitelská hodnota

otcové

plemenice

dcery

mléčná stáda

statistické údaje

mléčná užitkovost

dojivost

pořadí laktace

porod

sezónnost

analýza dat

populační genetika

interakce genotyp - prostředí

genetické zlepšení

trendy

prognózování

posouzení vlivu

matematické modely

odhad plemenné hodnoty > rok otelení

Popis jednotky:

3 grafy, 2 tabulky

Fyzický popis:

Ilustrace

Bibliografie:

Literatura na s. 450-451, záznamů