Evaluation of dried stoned olive pomace as supplementation for lactating Holstein cattle: effect on milk production and quality.

The aim of this study was to investigate the effect of using dried stoned olive pomace (DSOP) as a feed supplement for dairy cattle on productive performances and milk quality traits. Control (C) and experimental (E) diets were formulated and offered to lactating Italian Holstein cows placed into two groups (five cows each) that were homogenous for liveweight (630.8 vs 667.2 kg) and for the main physiological and productive traits. The E group received 1.181 kg on dry matter (DM) basis of DSOP as a part of the concentrates pool. The C group was fed an isoenergetic (0.90 milk forage units (FU)/kg DM) and isoprotein (161.4 g/kg DM crude protein (CP)) ration but without the inclusion of DSOP. DM intake was 21 kg/day and the experiment lasted 40 days. There were no significant effects of diet on cattle performance (liveweight and body condition score), milk yield and quality (fat, protein, lactose, urea) or coagulation traits (pH, r, K20, A30). The results showed that the inclusion of DSOP (5.61% of the total diet on DM basis) is not related to detrimental effects and could represent a valid supplement for dairy cattle.