Mashamaite et al., 2009. Livest. Res. Rural Dev., 21 (7)

This study related the amounts and types of tannins in some acacia tree species grown in Limpopo province to effects on short-term biological responses in rabbits. Eight New Zealand White male rabbits with a mean live weight of 0.680.05 kg were randomly assigned to metabolic crates in a two 4*4 Latin Square design. The four dietary treatments were a control diet (ground rabbit feed), control diet mixed with Acacia karroo leaf meal (4% of diet), control diet mixed with Acacia nilotica leaf meal (4% of diet) or control diet mixed with Acacia tortilis leaf meal (4% of diet). There were no differences (P>0.05) in diet intakes and digestibilities between the treatments. However, rabbits on Acacia tortilis diet drank more (P<0.05) water than those on the other treatments. Faecal DM and nitrogen outputs, urine output, urine nitrogen output and nitrogen retention in rabbits were not affected (P>0.05) by supplementation. Nitrogen digestibility and retention were most accurately predicted by contents of total phenolics, radial diffusion, precipitable phenolics by filter paper and polyethylene glycol in the leaves. Extracted condensed tannin contents provided no reliable indication of diet dry matter and nitrogen digestibilities, and faecal nitrogen output in rabbits.