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Titolo:
Weight coefficients of lactations in animal model
Autore:
Pribyl, J; Pribylova, J;
Indirizzi:
Res Inst Anim Prod, Prague 10401 10, Czech Republic Res Inst Anim Prod Prague Czech Republic 10401 10 401 10, Czech Republic
Titolo Testata:
CZECH JOURNAL OF ANIMAL SCIENCE
fascicolo: 7, volume: 46, anno: 2001,
pagine: 302 - 309
SICI:
1212-1819(200107)46:7<302:WCOLIA>2.0.ZU;2-S
Fonte:
ISI
Lingua:
ENG
Soggetto:
BREEDING VALUES; CATTLE;
Keywords:
dairy cattle; milk production; breeding value; animal model; selection index; weights of lactations;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
17
Recensione:
Indirizzi per estratti:
Indirizzo: Pribylova, J Res Inst Anim Prod, POB 1, Prague 10401 10, Czech Republic Res Inst Anim Prod POB 1 Prague Czech Republic 10401 10 blic
Citazione:
J. Pribyl e J. Pribylova, "Weight coefficients of lactations in animal model", CZEC J ANIM, 46(7), 2001, pp. 302-309

Abstract

Dairy cattle are selected for an average of lifetime milk production. Breeding value is estimated using MT-AM <multi-trait animal model>, (each lactation as separate trait). For each order of lactation discounted interest values are calculated, dependent on age structure and calving interval. The first lactation out of 10 lactations has a relative importance of the whole number of lactations. In the case of a 0% interest rate it is 0.34, with a 5% interest rate it is 0.37 and with a 10% interest rate it is 0.40. The average lifetime production is predicted on the basis of the early lactations. If the interest rate is 5%, the breeding value for the first lactation will predict the average lifetime production with reliability over 0.90, breeding values for the first two lactations with reliability over 0.98 and forthe first three lactations with reliability over 0.99. The age structure does not have a great influence on the reliability of prediction. Optimal weight in the index for partial breeding values, in case of the first lactation only, is approximately 1. In case of the first two lactations approximately 0.34 and 0.63, in case of the first three lactations 0.31, 0.11 and 0.52. If all the three lactations in the index have the same weight, i.e. 0.33, 0.33 and 0.33, the lifetime average production is predicted practically with equal reliability as in the optimal index. It is caused by high geneticcorrelations between lactations.

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Documento generato il 22/10/20 alle ore 06:09:26