LE TRANSIT DIGESTIF CHEZ LE LAPIN. V. — ÉVOLUTION DE L'EXCRÉTION FÉCALE EN FONCTION DE L'HEURE DE DISTRIBUTION DE L'ALIMENT ET DU NIVEAU DE RATIONNEMENT DURANT LES 5 JOURS QUI SUIVENT L'APPLICATION DE CE DERNIER

Abstract

Fecal excretion of hard feces (expressed in dry matter) was studied in 60 8-wk-old rabbits, receiving 70 or 100 g of pellets/day either at 9:30 a.m. or at 4:30 p.m., or receiving 100 g of pellets/day offered in 2 equal meals at the same hours as previously mentioned. Feces were collected every hour during 5 consecutive circadian cycles from the beginning of the feed restriction period. The rabbits were weighed every day. Three main parameters were used to study fecal excretion: the amount of dry matter, the number of hours of emission per 24 h and the weighted average hour for fecal excretion. The latter criterion is defined here. Effects of feed restriction level and feeding hour on the fecal excretion of hard feces were independent of each other. Whatever the experimental situation, this excretion only became stabilized from day 4 of the treatment. As compared to the rabbits receiving their food in the evening, those fed in the morning (single feeding) did not finish their ration. These animals exhibited the lowest weight gains; the amounts of hard feces excreted per 24 h were the same as those of the rabbits fed in the evening, but the excretion lasted longer (+1 h). The average hour for excretion of hard feces was located 6 h earlier within the circadian cycle, but was not as close to the feeding hour as in the former case. The lowest food allowance led to reduction of the weight gain and of the amount of hard feces excreted per 24 h; it also resulted in a shorter excretion period (6.7 versus 9.0 h) and in an earlier average hour for fecal excretion. As compared to single feeding, fractioning of the same quantity of food (100 g) into 2 meals led to reduction of the weight gain, a slight increase in the amount of feces excreted per 24 h, a number of excretion hours comparable to that obtained after only one morning meal and an average excretion hour located between those following single morning and evening feedings. If rabbits are subjected to limited feeding, the best method for the adaptation of the animals is to supply the whole ration once per day, late in the afternoon.