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Titolo:
Relationships between type and longevity in the Holstein breed
Autore:
Larroque, H; Ducrocq, V;
Indirizzi:
INRA, Genet Quantitat & Appl Stn, F-78352 Jouy En Josas, France INRA JouyEn Josas France F-78352 ppl Stn, F-78352 Jouy En Josas, France
Titolo Testata:
GENETICS SELECTION EVOLUTION
fascicolo: 1, volume: 33, anno: 2001,
pagine: 39 - 59
SICI:
0999-193X(200101/02)33:1<39:RBTALI>2.0.ZU;2-6
Fonte:
ISI
Lingua:
ENG
Soggetto:
HERD LIFE; GENETIC-PARAMETERS; TRAITS; CONFORMATION; CATTLE;
Keywords:
longevity; type traits; survival analysis; nonlinearity; dairy cattle;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
18
Recensione:
Indirizzi per estratti:
Indirizzo: Larroque, H INRA, Genet Quantitat & Appl Stn, F-78352 Jouy En Josas, France INRA Jouy En Josas France F-78352 8352 Jouy En Josas, France
Citazione:
H. Larroque e V. Ducrocq, "Relationships between type and longevity in the Holstein breed", GEN SEL EVO, 33(1), 2001, pp. 39-59

Abstract

The relationship between type traits and longevity was studied in the French Holstein breed using a survival analysis model. In this model, the phenotypic value adjusted for systematic fixed effects, the estimated breeding value, or the residual value (defined as the difference between the adjustedphenotypic value and the estimated breeding value) of the cow for each type trait was included as a risk factor. This was done separately for two subpopulations (registered and nonregistered herds) and with or without adjustment for production traits, i.e., considering true or functional longevity. For both types of herds, udder traits land above all, udder depth) clearlyinfluenced the length of productive life. There seemed to be a more pronounced voluntary culling on type traits in registered herds. The correction for the within herd-year class of production traits, as a way to approximatefunctional longevity, increased the importance of udder traits and decreased the weight of capacity traits. The same results were obtained when the phenotypic value of the cow for type was replaced by her estimated breeding value, whereas residuals had little impact. The relationship between longevity and type traits was most often nonlinear, in particular for udder traits, but in this study, no trait with a clear intermediate optimum was found.

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Documento generato il 04/12/20 alle ore 13:02:15