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Titolo: EFFECT OF DISEASE ON LENGTH OF PRODUCTIVE LIFE OF FRENCH HOLSTEIN DAIRYCOWS ASSESSED BY SURVIVAL ANALYSIS
Autore: BEAUDEAU F; DUCROCQ V; FOURICHON C; SEEGERS H;
 Indirizzi:
 INRA,SCH VET,ANIM HLTH MANAGEMENT UNIT,CP 3013 F44087 NANTES 03 FRANCE AGR UNIV WAGENINGEN,DEPT ANIM HUSB,DIV ANIM HLTH & EPIDEMIOL 6700 AH WAGENINGEN NETHERLANDS INRA,GENET QUANTITAT & APPL STN F78352 JOUY EN JOSAS FRANCE
 Titolo Testata:
 Journal of dairy science
fascicolo: 1,
volume: 78,
anno: 1995,
pagine: 103  117
 SICI:
 00220302(1995)78:1<103:EODOLO>2.0.ZU;2Z
 Fonte:
 ISI
 Lingua:
 ENG
 Soggetto:
 REPRODUCTIVEPERFORMANCE; FRIESIAN COWS; CATTLE; HERDS; SURVIVORSHIP; ASSOCIATION; LACTATION; MASTITIS; SYSTEM; MODEL;
 Keywords:
 LONGEVITY; DISEASE; SURVIVAL ANALYSIS;
 Tipo documento:
 Article
 Natura:
 Periodico
 Settore Disciplinare:
 Science Citation Index Expanded
 Science Citation Index Expanded
 Citazioni:
 34
 Recensione:
 Indirizzi per estratti:



 Citazione:
 F. Beaudeau et al., "EFFECT OF DISEASE ON LENGTH OF PRODUCTIVE LIFE OF FRENCH HOLSTEIN DAIRYCOWS ASSESSED BY SURVIVAL ANALYSIS", Journal of dairy science, 78(1), 1995, pp. 103117
Abstract
Data from a survey performed from 1986 to 1990 were analyzed to assess the effects of diseases on length of productive life of 3589 Holstein cows from 47 herds, using a proportional hazard model. The probability of a cow being culled, or hazard function, was supposed to be the product of an unspecified baseline hazard function and loglinear, timedependent explanatory variables that possibly influence culling rate (Cox's regression). The effect of 16 health events was studied according to lactation number of occurrence. The model included adjustments for effects of herdyearseason (considered to be random), month of calving, stage of lactation, lactation number, reproductive performance, and milk production. The probability of a cow being culled increased in early and late stages of lactation in older cows, in low producing cows, and in cows with poor reproductive performance. Mastitis before the peak of lactation or during the dry period increased the risk (relative culling rate in first lactation, 1.3 and 4.0, respectively). Teatinjuries and nontraumatic udder disorders had a large impact on longevity. Cows with late metritis or early abortion had poor survival. Thedecrease in median length of productive life could be over a standardlactation in particular cases. Expected survivor curves, computed after assumption of a priori values of covariates and their evolution over time, appear to be powerful tools for examining the effect of healthdisorders on length of productive life of cows.
ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/12/20 alle ore 12:56:16