Amélioration de la mesure et de la prévision de l'ingestibilité des fourrages chez le mouton par la prise en compte des variations de la capacité d'ingestion à l'aide d'un fourrage témoin
Jean Pierre Dulphy, René Baumont, Louis L'Hotelier, Camille Demarquilly, Marinette Jailler, Jacqueline Jamot, Aline Détour
1999
Annales de Zootechnie
Improvement of the measurement and prediction of forage ingestibility in sheep by taking into account the variations of their intake capacity using a standard forage. Sheep present important variations of their intake capacity that are related, for example, to the photoperiod. This s makes it difficult to estimate the ingestibility of conserved forages, because they may be fed at different periods of the year. A method is proposed to standardise the measure of this forage ingestibility and to
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... ke it independent of the main factors influencing the intake capacity. Thus, the ingestibility of 5 1 forages was measured on Ito 2-year-old Texel wethers. To correct the effect of different factors ( the photoperiod and the group effect) which intluence the intake capacity of these animals, a standard hay was fed before and after all sequences of measurements. The evolution of intake capacity was estimated with this hay, for each group of six sheep, for each period of measurement, by linear interpolation between two measures concerning the standard hay. Under these conditions, it appears that: 1) the intake capacity of wethers leads to an under-estimation of forage ingestibility in December-January and to a overestimation in May-September; 2) the proposed correction is well justified; indeed, the relationship between ingestibility and NDF content, a classical prediction criteria, gives a residual standard deviation of 9.9 g DM.kg-1 light weight (LW) 0 -1 5 before correction, and to 5.2 after correction; 3) the correction makes it possible to conclude that ingestibility of well-cured hays and silages is nearly equivalent to initial fresh forages. It is proposed to use this method of correction each time, when measurements of ingestibility are achieved on sheep, at different seasons, and/or with different group of animals, and when the results have to be pooled. (© Elsevier / Inra) ingestibiliy / forages / ingestive capacity / sheep / methodology Résumé -Les ovins présentent des variations importantes de leur capacité d'ingestion liées, entre autres facteurs, à la photopériode. Ceci rend difficile l'estimation de l'ingestibilité des fourrages conservés, car leur mesure peut avoir lieu à différentes périodes de l'année. Cette note propose une Tél. : 04 73 62 40 77; fax : 04 73 62 42 73 ; dulphy@clermont.inra.i'r
doi:10.1051/animres:19990606
fatcat:otzglz6mljgwlfkssozvtg3ubq