Evaluation of different ensiling methods for preservation: influence on chemical composition and ruminal fermentation.

is a brown seaweed that could be used in ruminant feeding, but its fast deteriorating and seasonal growth nature limit their utilisation in the practice. Ensiling could be used as a preservation method, but information of its effects on the nutritional value of the seaweed is limited. This study evaluated the ruminal fermentation of different silages using ruminal inoculum either from goats fed a mixed diet (60:40 oat hay:concentrate) or from sheep fed a high-forage diet (90:10 alfalfa hay:concentrate) to simulate different small ruminant production systems. was ensiled in vacuum bags without additives (Control), with formic acid (4 g/kg seaweed; FA), with lactic acid bacteria (LAB) or with LAB after a pre-wilting treatment to reach a seaweed dry matter (DM) content of 30% (30LAB). Ensiling decreased ( < 0.05) the content in DM, neutral detergent fibre and total extractable polyphenols, but nitrogen and fat content were unaffected. For both ruminal inoculums, ensiling decreased ( < 0.05) the asymptotic gas production after 120 h of fermentation (excepting for FA silage with goats' inoculum), but the total volatile fatty acid (VFA) production was unaffected. The VFA profile shifted towards greater ( < 0.05) acetate and lower ( < 0.05) propionate proportions in all silages compared with the pre-ensiling . When goats inoculum was used, greater ( < 0.05) CH production compared with pre-ensiling was observed in all silages, except Control one, which led to greater ( < 0.05) CH/total VFA ratio. In contrast, no differences among samples ( > 0.05) in either CH production or CH/total VFA ratio were observed when sheep' inoculum was used. Fermentation of all samples started earlier with goats' inoculum than with sheep' inoculum, which was attributed to the different diet fed to the animals. These results suggest that ensiling with either formic acid or lactic acid bacteria could be a viable conservation method to preserve the nutritive value.