Effects of Posidonia oceanica banquettes on intake, digestibility, nitrogen balance and metabolic profiles in sheep.
The marine plant Posidonia oceanica (L.) (PO) has been demonstrated in goats to be a source of fibre. The aim of the present study was to assess the effects of introducing this marine plant as a substitute for barley straw in the feed of mature ewes, assessing the effects of its addition on intake, digestibility and ruminal fermentation and on the ewes' metabolic profiles (energy and protein). PO was used at 75 g day-1 per ewe (15% of the total forage), 150 g day-1 per ewe (30% of the total forage) and 300 g day-1 per ewe (60% of the total forage). Substitution of 15% of the forage with PO has no negative consequences on dry matter intake, final live weight and metabolic status in mature ewes; in addition, PO may improve the animal's nitrogen utilisation. The upper limit of substitution was 30%, where only few changes were noted without metabolic consequences. Substitution of 60% impaired performance and affects tissue functions in the animal's body. Moderate quantities of barley straw (between 75 and 150 g day-1 per ewe) can be replaced by PO in feed rations for mature ewes. © 2017 Society of Chemical Industry.