Use of ostrich faeces as alternative inoculum to caecal content to study the in vitro digestibility of alfalfa (green, dehydrated and hay)

Abstract

In order to find an alternative source of inoculum to caecal content for studying the in vitro feed digestibility in domesticated ostriches, caecal content and faeces of 4 male birds were used as inocula for an in vitro gas production trial. Three alfalfa (hay, AH; green , GA; dehydrated, DA) were used as substrates. Caecal content and faeces, diluted respectively 1:2 (CI) and 1:4 (FI) with an anaerobic medium and were used as inocula. Gas production was recorded 22 times up to 120 h of incubation and fermentation characteristics (e.g. degraded organic matter, OMd; potential gas production, A; maximum fermentation rate, Rmax; volatile fatty acid, VFA) were studied by inoculum and substrate. CI showed a higher OMd (67.90 vs 64.60 %, respectively for CI and FI, P < 0.01) but lower A (200.6 vs 212.6 ml/g, respectively for CI and FI, P < 0.01) and Rmax (5.94 vs 6.56 ml/h, respectively for CI and FI, P < 0.05) than FI. No differences were found in tVFA production. The significant higher value of branched chain proportion [(isovaleric + isobutyrate)/tVFA] for CI (0.039 vs 0.032 respectively for CI and FI, P < 0.05) indicate a higher degradation protein for this inoculum.

Keywords

• Ostrich, Caecal content, Faeces, In vitro gas production technique.