000148657 001__ 148657
000148657 005__ 20250120165543.0
000148657 0247_ $$2doi$$a10.1186/s12711-024-00945-z
000148657 0248_ $$2sideral$$a141952
000148657 037__ $$aART-2025-141952
000148657 041__ $$aeng
000148657 100__ $$aAntonios, Simona
000148657 245__ $$aGenetic inbreeding load and its individual prediction for milk yield in French dairy sheep
000148657 260__ $$c2025
000148657 5060_ $$aAccess copy available to the general public$$fUnrestricted
000148657 5203_ $$aBackground: The magnitude of inbreeding depression depends on the recessive burden of the individual, which can be traced back to the hidden (recessive) inbreeding load among ancestors. However, these ancestors carry different alleles at potentially deleterious loci and therefore there is individual variability of this inbreeding load. Estimation of the additive genetic value for inbreeding load is possible using a decomposition of inbreeding in partial inbreeding components due to ancestors. Both the magnitude of variation in partial inbreeding components and the additive genetic variance of inbreeding loads are largely unknown. Our study had three objectives. First, based on substitution effect under non-random matings, we showed analytically that inbreeding load of an ancestor can be expressed as an additive genetic effect. Second, we analysed the structure of individual inbreeding by examining the contributions of specific ancestors/founders using the concept of partial inbreeding coefficients in three French dairy sheep populations (Basco-Béarnaise, Manech Tête Noire and Manech Tête Rousse). Third, we included these coefficients in a mixed model as random regression covariates, to predict genetic variance and breeding values of the inbreeding load for milk yield in the same breeds. Results: Pedigrees included 190,276, 166,028 and 633,655 animals of Basco-Béarnaise, Manech Tête Noire and Manech Tête Rousse, respectively, born between 1985 and 2021. A fraction of 99.1% of the partial inbreeding coefficients were lower than 0.01 in all breeds, meaning that in practice inbreeding occurs in pedigree loops that span several generations backwards. Less than 5% ancestors generate inbreeding, because mating is essentially between unrelated individuals. Inbreeding load estimations involved 658,731, 541,180 and 2,168,454 records of yearly milk yield from 178,123, 151,863 and 596,586 females in Basco-Béarnaise, Manech Tête Noire and Manech Tête Rousse, respectively. Adding the inbreeding load effect to the model improved the fitting (values of the statistic Likelihood Ratio Test between 132 and 383) for milk yield in the three breeds. The inbreeding load variances were equal to 11,804 and 9435 L squared of milk yield for a fully inbred (100%) descendant in Manech Tête Noire and Manech Tête Rousse. In Basco-Béarnaise, the estimate of the inbreeding load variance (11,804) was not significantly different from zero. The correlations between (direct effect) additive genetic and inbreeding load effects were − 0.09, − 0.08 and − 0.12 in Basco-Béarnaise, Manech Tête Noire and Manech Tête Rousse. Conclusions: The decomposition of inbreeding in partial coefficients in these populations shows that inbreeding is mostly due to several small contributions of ancestors (lower than 0.001) going back several generations (5 to 7 generations), which is according to the policy of avoiding close matings. There is variation of inbreeding load among animals, although its magnitude does not seem enough to warrant selection based on this criterion.
000148657 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/
000148657 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000148657 700__ $$aRodríguez-Ramilo, Silvia T.
000148657 700__ $$aLegarra, Andres
000148657 700__ $$aAstruc, Jean-Michel
000148657 700__ $$0(orcid)0000-0001-6256-5478$$aVarona, Luis$$uUniversidad de Zaragoza
000148657 700__ $$aVitezica, Zulma G.
000148657 7102_ $$11001$$2420$$aUniversidad de Zaragoza$$bDpto. Anatom.,Embri.Genét.Ani.$$cÁrea Genética
000148657 773__ $$g57, 1 (2025), [11 pp.]$$pGenet. sel. evol.$$tGenetics Selection Evolution$$x0999-193X
000148657 8564_ $$s1390910$$uhttps://zaguan.unizar.es/record/148657/files/texto_completo.pdf$$yVersión publicada
000148657 8564_ $$s2566129$$uhttps://zaguan.unizar.es/record/148657/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000148657 909CO $$ooai:zaguan.unizar.es:148657$$particulos$$pdriver
000148657 951__ $$a2025-01-20-14:54:59
000148657 980__ $$aARTICLE