Impact of caecotrophy on rate of passage, intake and faecal excretion pattern in the growing rabbit.

Abstract

Rate of passage was measured on 12 rabbits, either allowed to practice caecotrophy (Control period, from 56 to 60 days of age) or prevented from consuming soft faeces by wearing a plastic collar (without soft faeces intake = WSF periods, 63-66 d old and 70-73 d old). Measurements of digestive transit of the solid phase of the digesta were carried out by analysing the kinetics of faecal excretion of a fibre particles labelled with 141Ce. The excretion pattern of hard and soft faeces, hourly quantified during three complete 24-h cycle during WSF periods, showed that hard faeces excretion averaged 35.3 ± 3.2 g/day DM, while caecotrophes excretion was meanly 10.7 ± 2.6 g DM/d for a mean feed intake of 113.7 g DM/d. During the control period, daily hard faeces excretion was not significantly different (36.4 ± 3.0 g DM/d, for a feed intake of 110.8 g DM/d). The DM digestibility did not differ during control and WSF periods (67.2 and 67.8%). If caecotrophe production is included in the DM digestibility calculation, coefficient fell by 10.5 units (mean = 57.3%). When soft faeces intake was prevented (period WSF), the mean retention time in the whole tract evolved from 23 h (Control) to 15 h (-34%) and the minimal transit time was 50% shorter. The caecal mean retention time passed from 17 h in Control to 10 h (-40%) in WSF period. Caecal retention of large particles seemed less affected (CRlp:- 23%) than fine (CRfp:-48%).