EUROPEAN GROUP ON RABBIT NUTRITION
  

 

            contact with us

MEASUREMENT OF ILEAL DIGESTIBILITY IN RABBITS: AN INTER-LABORATORY STUDY TO COMPARE TWO MARKERS AND TWO FREQUENCIES OF DIGESTA COLLECTIONS

BLAS, E.(1), FALCAO E CUNHA, L.(2), GIDENNE, T.(3), PINHEIRO, V.(4), GARCÍA, A.I.(5), CARABAÑO, R.(5)


(1) Departamento de Producción Animal y Ciencia de los Alimentos. Universidad Cardenal Herrera CEU. Moncada. Spain.
(2) Instituto Superior de Agronomia, Secção de Zootecnia. Lisboa. Portugal.
(3) Station de Recherches Cunicoles. INRA. Castanet-Tolosan. France.
(4) UTAD, Secção de Zootecnia. Vila Real. Portugal.
(5)Departamento de Producción Animal. Universidad Politécnica de Madrid. Spain.

ABSTRACT: In four laboratories, a total of 52 adult rabbits were fitted with a single T glass cannula at terminal ileum. After surgery recovery, all animals were fed ad libitum with the same batch of a diet doubly labelled, by addition of Yb attached to fibre particles and Cr as Cr2O3. Faecal recovery of both markers and their concentration in ileal digesta and soft faeces were determined to study their suitability to be used in ileal digestibility measurements. The effect of frequency of ileal digesta collections (one or two per day) on ileal digesta composition and ileal digestibility of DM, CP, NDF and ADF was evaluated. Yb behaved as expected for a marker of the digesta flow. On the contrary, Cr content was lower in hard faeces (201.4  3.8 mg/kg DM) than in ileal digesta (248.6  3.7 mg/kg DM) and it showed the lowest values in soft faeces (136.2  3.7 mg/kg DM), that might result in an overestimation of the ileal digestibility; in addition, its faecal recovery was very low (53.6  1.3 %). These findings support that Cr added to diet as Cr2O3 seems inadequate to labelling rabbit diets. No effects of frequency of ileal digesta collections on ileal digesta composition and ileal digestibility were detected; that allows to reduce the length of ileal digesta sampling period from 6 to 3 days. Ileal digestibility of DM averaged 38.1% and differences among laboratories tended to be significant (P=0.064), being its residual variability (CV=17.9%) higher than that observed for faecal digestibility of DM (CV=3.5%). Ileal and faecal digestibility of CP, NDF and ADF differed significantly among laboratories, being the residual variability also higher for ileal than for faecal values.