ORBi: Hammami Hedi - Prediction of cow pregnancy status using conventional and novel mid-infrared predicted milk traits

Reference : Prediction of cow pregnancy status using conventional and novel mid-infrared predicted m...


	Document type :	Scientific congresses and symposiums : Paper published in a book
	Discipline(s) :	Life sciences : Genetics & genetic processes Life sciences : Biotechnology Life sciences : Animal production & animal husbandry
	To cite this reference:	http://hdl.handle.net/2268/98970

Title :	Prediction of cow pregnancy status using conventional and novel mid-infrared predicted milk traits
Language :	English
Alternative title :	[en] Prediction de l'état de gestation des vaches laitières en utilisant les données conventionnelles et les nouveaux prédicteurs issus de l'analyse du lait avec le moyen infra-rouge
Author, co-author :	Hammami, Hedi [Université de Liège - ULg > Sciences agronomiques > Zootechnie >]
	Bastin, Catherine [Université de Liège - ULg > Sciences agronomiques > Zootechnie >]
	Gillon, Alain [ > > ]
	Arnould, Valérie [Université de Liège - ULg > Sciences agronomiques > Zootechnie >]
	stoll, Jean [ > > ]
	Soyeurt, Hélène [Université de Liège - ULg > Sciences agronomiques > Zootechnie >]
	Gengler, Nicolas [Université de Liège - ULg > Sciences agronomiques > Zootechnie >]
Publication date :	Aug-2011
Main document title :	Book of Abstracts of the 62nd Annual Meeting of the European Association for Animal Production
Publisher :	Wageningen Academic Publishers
On invitation :	No
Audience :	International
ISBN :	978-90-8686-177-4
City :	Wageningen
Country :	The Netherlands
Event name :	62nd Annual Meeting of the European Association for Animal Production
Event date :	du 29 août 2011 au 02 septembre 2011
Event organizer :	European Association for Animal Production
Event place (city) :	Stavanger
Event country :	Norway
Keywords :	[en] dairy cattle ; pregnancy ; predictive models ; milk composition
Abstract :	[en] The objective of this study was to determine the ability of conventional milk cow characteristics and novel traits predicted by mid infrared (MIR) obtained from milk recording to predict the pregnancy status once the cow was inseminated. Conventional milk recording, spectral, and reproductive data collected in Luxembourg Hoslteins between 2008 and 2010 were used. Cows were defined as pregnant if they were positively checked and calved between 267 and 295 d later after the last AI or if they had calved between the later intervals when no checks were recorded. Pregnant or not within 3 intervals after last AI (<=35 d, 45-60 d, and 60-90 d) was modeled using logistic regression models firstly as a function of conventional cow milk characteristics and extended to fatty acids as novel traits predicted by MIR in a second step. The lactation curve characteristics for milk, fat, protein, and lactose yields were estimated using modified best prediction method. Test-day fatty acid contents were estimated from collected MIR spectra using an appropriate calibration equation. Two third proportion and one third of the whole data set were randomly selected for calibration and validation models respectively. The relation between the predicted and observed probabilities of cow pregnancy was approximately linear for calibration and validation models. The sensitivity-specificity combination for cow pregnancy increased when fatty acids were added to conventional milk characteristics as inputs to the different models (from 78 to 85% for sensitivity and from 40 to 52% for specificity). Results based on those models showed that it would be possible to help breeders to manage cow fertility using such tool implemented in the milk recording organizations.
Funders :	INTERREG IVB NWE; Région wallonne; FNRS
Target :	Researchers ; Professionals ; Students ; General public
Permalink :	http://hdl.handle.net/2268/98970
Other URL :	http://www.eaap.org/Stavanger/Stavanger_Book_of_Abstracts.pdf

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