Technical note: Preliminary results with a tannin extract on the performance and mortality of growing rabbits in an enteropathy infected environment

Abstract

In 3 preliminary trials, the effect of a dietary addition with 0.5% of a chestnut tannin extract, containing approximately 55% hydrolysable tannins, was examined on mortality after weaning. The tannin-enriched diet was fed to the does and their litters from 22 days of lactation. After weaning (day 29), young rabbits did not change dietary treatment and remained on the control diet or the tannin-enriched diet, respectively. In total 1217 rabbits were considered, about half of whom were fed the tannin-enriched diet. Mortality reached 17.1% and 7.7% (trial 1, P=0.054), 17.2 and 18.2% (trail 2, NS) and 29.0% and 9.9% (trial 3, P<0.001) in controls and tannin-fed rabbits, respectively. The autopsy on 6 control rabbits revealed typical symptoms of rabbit epizootic enteropathy with a predominance of Clostridium spiroforme. Weight gain was determined only in trial 3 and was significantly higher in tannin-fed rabbits (average weight at 57 d of age: 1893 and 2005 g, respectively; P<0.01). Some hypotheses are formulated to explain these preliminary results, but they still have to be verified.