Prediction of in vivo digestibility of pasture-based diets in dairy goats from faecal indicators

Alexia Charpentier (1, 2) , Solveig Mendowski (2) , Remy Delagarde (2)

1 FERLUS - Fourrages Environnement Ruminants Lusignan
2 PEGASE - Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Elevage [Rennes]

For estimating quality and intake of pasture herbage by grazing goats, estimation of herbage digestibility is often required. The aim of this work was to predict in vivo organic matter digestibility (OMD) of diets based on temperate pasture forage from faecal composition (CP mainly). A series of indoor experiments was carried out with goats fed on grass hay or with fresh herbage cut daily and given either ad libitum or in restricted amounts, to mimic the effect of pasture herbage availability. Concentrate supplementation level and regrowth age of the herbage were also studied in order to achieve a wide range of diets composition and quality. Intake of each feed, and of faecal output (total collection), were measured precisely during 5 consecutive days in each experimental period. For each dataset (fresh pasture herbage only or fresh pasture herbage + hay), there was a strong and inverse relationship between OMD and faecal crude protein (CP) concentration. Including dietary CP concentration in the regression allowed increased accuracy of the prediction. The proposed equations, relevant for good quality pastures, show a good continuum with previous published equations on goats fed on much less digestible tropical, Mediterranean or Sahelian forages.

Mots clés: nannygoats; grazing; digestibility; animal feeding; Goat; Pasture; Faecal nitrogen; Prediction

Mots clés: chèvre; pâturage; digestibilité; azote fécal; alimentation animale; équation de prédiction

Domaines: Sciences du Vivant [q-bio]

Alexia Charpentier, Solveig Mendowski, Remy Delagarde. Prediction of in vivo digestibility of pasture-based diets in dairy goats from faecal indicators. 19. Symposium of the European Grassland Federation (EGF), May 2017, Alghero, Italy. ⟨hal-01605503⟩