Suckling rabbit digestibility: effect of the age at introduction of a starter feed

Early feeding in the nest is a promising biomimetic s rategy to improve gut health and prevent digesti v diseases. To formulate adequate starter feed, it is essential to determine the nutritional values of t he preweaning diets. However, the assessment of suckling rabbits’ digestion is challenging since the kits ar e raised together with their mother along with the fa ct that gut morphology and functionalities are deep ly changing during the transition from milk to solid f eed. To study the digestive capacity of the young r abbits, a 15-days digestibility trial was performed from 21 days of age to weaning on rabbits provided with ea rly feeding or not. A mother-litter separate feeding sy stem with controlled suckling was used to monitor i ntake and faecal excretion of 20 litters. All the litters had access to pellet feeds from 15 days. A starter feed in a form of a gel was provided as early as 3 days of ag e to half of the litters. Gut development dynamics and milk intake were taken into account to adjust faeca l digestibility calculations. Digestibility coeffic ients of dry matter, crude protein, gross energy, and fibre fractions (NDF, ADF, Hemicelluloses) were high between 21 and 24 days (64%, 72%, 68%, 44%, 37% and 55%, respectively) and were followed by a decrease between 25 and 27 days (-16%, -10%, -16%, -32 , -37%, -7%). Starter feed supplementation did not modify faecal digestibility. Our original data revealed a short period where digestive capacity of the rabbit seemed to be overwhelmed by the sudden influ x o dry matter in the gut. This could be implement ed in the future for pre-weaning feed formulation.