Feeding behaviour, oxidative status, and milk production of dairy ewes fed fresh or dehydrated sulla (Sulla coronaria (L.) Medik.) forage

This investigation aimed to explore utilisation of sulla as fresh or stored forage, and the improvement of forage stocks by dehydration as alternative to haymaking for reducing biomass and nutrients losses and preserving properties of bioactive components, mainly condensed tannins. In two experiments carried out in spring and autumn, the responses of Valle del Belìce ewes to different diets were evaluated for their feeding behaviour, oxidative status and milk production. In spring, 12 ewes were divided into two groups fed diets consisting of fresh forage of SULLA or BARLEY ad libitum according to a 2 × 2 Latin square design (LSD). In autumn, pellets of dehydrated sulla forage (DSF) cut in April or May were compared with sulla hay (SH); a 3 × 3 LSD involved 9 ewes, divided into three groups fed the diets: A-DSF, 2 kg/day of April pellets and SH ad libitum; M-DSF, 2 kg/day of May pellets and SH ad libitum; SHL, SH ad libitum. Concentrate feed was provided at 600 (spring) or 800 g/day (autumn). Ewes fed SULLA significantly improved milk yield, milk casein, efficiency of DM and energy conversion to milk and antioxidant balance than BARLEY ewes. Both DSF diets significantly increased feed intake, DM and energy digestibility, and milk yield, whereas A-DSF induced a higher plasma free polyphenols level. These results confirm the potential of sulla as fresh or dehydrated forage in small ruminants’ feeding, and evidence how dehydration can represent an alternative to haymaking, ensuring ewes’ health and dairy production in periods of unavailable fresh forage.