[Effect of the addition of a fiber-rich concentrate to a hay-based diet, offered at two levels of feeding in the adult rabbit. 2. Measurements of digestibility].
The effect of adding a fibre-rich concentrate (wheat bran or beet pulp) to a hay-based diet (cook's foot-lucerne: 50/50) on the apparent digestibility of diets was measured in three groups of 8 adult doe rabbits (New-Zealand White X Californian). Diet composition was as follows: 90% hay only (diet F), hay + bran (diet FS) or hay + pulp (diet FP). Two levels of feeding were tested: ad libitum and 2/3 of ad libitum intake. Addition of wheat bran and especially of beet pulp led to a significant increase in the apparent digestibility of the whole diet. Our results confirm the high digestibility of cell-wall constituents of beet pulp: the apparent digestibility coefficient of hemicellulose in diet FP reached 60% (versus 23% for diet F) and that of cellulose 45% (21% for diet F). Wheat bran supplied digestible hemicellulose (ADC = 48% for diet FS) while the apparent digestibility of bran cellulose was not higher than that of hay (ADC = 22%). This digestive interaction between raw material was accompanied by an interaction with the digestive transit. The less digestible diet (diet F) exhibited the shortest mean residence time (MRT). However, diet FS exhibited the longest residence time whereas it was less digestible than diet FP. These results suggest that, in the rabbit, wheat bran is a transit-regulator as already observed in other species. Measuring apparent digestibility between the 10th and the 16th day of the feed restriction was too early for our doe rabbits. Values measured were not significantly different from those obtained during ad libitum feeding, although the MRT of diets was longer during restricted feeding.
Gidenne
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Laboratoire de Recherches sur l'Elevage du Lapin, I.N.R.A., Castanet Tolosan, France.
D000818:Animals; D004032:Diet; D004043:Dietary Fiber; D004063:Digestion; D005260:Female; D006109:Poaceae; D011817:Rabbits / Q000502:physiology*
Effet de l'addition d'un "concentré" riche en fibres dans une ration à base de foin, distribuée à deux niveaux alimentaires chez la lapine adulte. 2. Mesures de digestibilité.