Genetic analysis of clinical mastitis during different risk periods in Finnish Ayrshire

Clinical mastitis (CM) records from first-lactation Finnish Ayrshire were analysed by linear and threshold models to assess the effects trait definition on estimates of genetic parameters and sire evaluation. The studied CM traits were defined by dividing lactation into six lactation stages (risk pe...

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Main Authors: E. NEGUSSIE, I. STRANDÉN, E. MÄNTYSAARI
Format: Article
Language:English
Published: Scientific Agricultural Society of Finland 2008-12-01
Series:Agricultural and Food Science
Online Access:https://journal.fi/afs/article/view/5867
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spelling doaj-482ee04cf2ef4d48ad5e1f5600a330522020-11-24T21:43:30ZengScientific Agricultural Society of FinlandAgricultural and Food Science1459-60671795-18952008-12-01162 Genetic analysis of clinical mastitis during different risk periods in Finnish AyrshireE. NEGUSSIEI. STRANDÉNE. MÄNTYSAARIClinical mastitis (CM) records from first-lactation Finnish Ayrshire were analysed by linear and threshold models to assess the effects trait definition on estimates of genetic parameters and sire evaluation. The studied CM traits were defined by dividing lactation into six lactation stages (risk periods) by days (d) after calving: CM1 (-7 to 150 d), CM2 (-30 to 30 d), CM3 (-30 to 150 d), CM4 (31 to 150 d), CM5 (150 to 300 d), CM6 (-30 to 300 d). In addition, two data sets were prepared to assess the effect of excluding (Data I) or including (Data II) records of culled cows on estimates of genetic parameters. Sire variances and heritabilities were larger using Data II. When data from longer intervals was used heritabilities of CM were slightly higher than shorter intervals indicating that longer intervals tend to obscure genetic variation between animals. Of all CM traits, heritability of liability to CM with threshold-liability model was highest for CM2 (h2=0.083) implying that most of the genetic information on CM is in early lactation. In sire evaluation, a multitrait index calculated by combining CM2, CM4 and CM5 had the highest correlation with all other univariate CM trait evaluations. This and the magnitude (less than 1.0) of genetic correlations between CM traits suggest that a multitrait model considering CM from the different risk periods would be appropriate for CM sire evaluation.;https://journal.fi/afs/article/view/5867
collection DOAJ
language English
format Article
sources DOAJ
author E. NEGUSSIE
I. STRANDÉN
E. MÄNTYSAARI
spellingShingle E. NEGUSSIE
I. STRANDÉN
E. MÄNTYSAARI
Genetic analysis of clinical mastitis during different risk periods in Finnish Ayrshire
Agricultural and Food Science
author_facet E. NEGUSSIE
I. STRANDÉN
E. MÄNTYSAARI
author_sort E. NEGUSSIE
title Genetic analysis of clinical mastitis during different risk periods in Finnish Ayrshire
title_short Genetic analysis of clinical mastitis during different risk periods in Finnish Ayrshire
title_full Genetic analysis of clinical mastitis during different risk periods in Finnish Ayrshire
title_fullStr Genetic analysis of clinical mastitis during different risk periods in Finnish Ayrshire
title_full_unstemmed Genetic analysis of clinical mastitis during different risk periods in Finnish Ayrshire
title_sort genetic analysis of clinical mastitis during different risk periods in finnish ayrshire
publisher Scientific Agricultural Society of Finland
series Agricultural and Food Science
issn 1459-6067
1795-1895
publishDate 2008-12-01
description Clinical mastitis (CM) records from first-lactation Finnish Ayrshire were analysed by linear and threshold models to assess the effects trait definition on estimates of genetic parameters and sire evaluation. The studied CM traits were defined by dividing lactation into six lactation stages (risk periods) by days (d) after calving: CM1 (-7 to 150 d), CM2 (-30 to 30 d), CM3 (-30 to 150 d), CM4 (31 to 150 d), CM5 (150 to 300 d), CM6 (-30 to 300 d). In addition, two data sets were prepared to assess the effect of excluding (Data I) or including (Data II) records of culled cows on estimates of genetic parameters. Sire variances and heritabilities were larger using Data II. When data from longer intervals was used heritabilities of CM were slightly higher than shorter intervals indicating that longer intervals tend to obscure genetic variation between animals. Of all CM traits, heritability of liability to CM with threshold-liability model was highest for CM2 (h2=0.083) implying that most of the genetic information on CM is in early lactation. In sire evaluation, a multitrait index calculated by combining CM2, CM4 and CM5 had the highest correlation with all other univariate CM trait evaluations. This and the magnitude (less than 1.0) of genetic correlations between CM traits suggest that a multitrait model considering CM from the different risk periods would be appropriate for CM sire evaluation.;
url https://journal.fi/afs/article/view/5867
work_keys_str_mv AT enegussie geneticanalysisofclinicalmastitisduringdifferentriskperiodsinfinnishayrshire
AT istranden geneticanalysisofclinicalmastitisduringdifferentriskperiodsinfinnishayrshire
AT emantysaari geneticanalysisofclinicalmastitisduringdifferentriskperiodsinfinnishayrshire
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