Genotype by environment interaction for livability of dairy calves from first parity cows

Abstract

Death of calves around parturition is a matter of concern for dairy farmers. Relatively high stillbirth rates and unfavourable trends have been reported for Holstein heifers in the Netherlands and several other countries. In our study, we investigated herd differences, genetic parameters and genotype by environment interaction for heifer calf livability. A large dataset with data from calvings between 1993 and 2012 of Dutch dairy farms was used. There were considerable differences between herds in livability of calves from heifers, with averages ranging from 74% to 95%. Both herds with relatively high and low averages showed the same negative trend between 1993 and 2012, with largest declines in herds with the lowest averages. We found that heritability and genetic variation of first parity livability were substantially larger in herd environments where the likelihood of stillbirth was high v. environments where stillbirth was at a low level. The genetic correlations between herd environment levels were all very close to unity, indicating that ranking of sires was similar for all environments. However, for herds with a relatively high stillbirth incidence selecting sires with favourable breeding values is expected to be twice as profitable as in herds with a relatively low stillbirth incidence.

Genotype by environment interactions in fertility traits in New Zealand dairy cows

“…Given unreliable estimates from other aspects of this analysis, these results should be viewed with caution. However, findings are similar to recent research investigating G×E for livability (survival) of dairy calves from primiparous cows (Ouweltjes et al, 2015). Those researchers found across-environment genetic correlations close to 1, indicating no G×E.…”

Genotype-environment interaction for age at first calving in Holstein cows in Brazil

“…A similar result was found by Scarpati and Lôbo (1999) , with lower additive genetic variance generating lower heritability estimates. Ouweltjes, Windig, Van Pelt and Callus (2015) also found a tendency of higher heritability in less favorable environments when evaluating calf mortality rate in first-calving dairy cows in the Netherlands; they found two-fold the heritability for unfavorable environments when compared to favorable environments. Similarly, Ismael et al.…”

Vroege sterfte van biggen, kalveren en melkgeitenlammeren : Percentages, oorzaken en mogelijkheden tot reductie

“…Vroege sterfte van kalveren is niet alleen in Nederland een probleem (Ouweltjes et al 2015), maar wordt ook internationaal als een belangrijk welzijnsissue gezien. Mee 2013…”

“…Er worden tegenwoordig fokwaarden berekend waarmee stieren kunnen worden gerangschikt op de levensvatbaarheid van hun kalveren. Uit het onderzoek van Ouweltjes et al (2015) bleek dat zowel de erfelijkheidsgraad als de genetische variatie voor levensvatbaarheid van kalveren van vaarzen groter was voor bedrijven met relatief veel perinatale sterfte, terwijl de rangorde van stieren niet wezenlijk verschilde tussen bedrijfsniveaus voor perinatale sterfte. Dat betekent enerzijds dat bedrijven met problemen meer baat hebben bij selectie van goede stieren dan bedrijven met weinig problemen, en anderzijds dat stieren waarvan relatief weinig kalveren sterven op goede bedrijven dezelfde zijn als die waarvan relatief weinig kalveren sterven op probleembedrijven.…”