Production and Quality of Meat from Lambs Fed Fresh Sulla Forage (Sulla coronaria (L.) Medik)

This study aimed to evaluate the effects of fresh sulla forage (FSF) in the diet on intake, growth, carcass traits, and meat quality of lambs. Twenty-four male lambs of Comisana breed (age 80±8 days; live weight 17.8±3.2 kg) were assigned to 2 groups receiving, until slaughter (age 128±8 days), FSF (crude protein (CP) 174 g/kg dry matter (DM), condensed tannins (CT) 15.6 g/kg DM) or alfalfa hay pellets (AHP, CP 181 g/kg DM), and a faba beans and barley mixture offered ad libitum. The greater forage intake of FSF lambs (451 vs 306 g DM/day; p<0.0001) corresponded to a lower incidence of concentrate in the diet (51.3 vs 64.2 % DM; p<0.0001) and in a not significant increase in final live weight (27.3 vs 26.0 kg), leading to an equal feed conversion ratio (4.90) between diets. The FSF diet tended to limit perirenal and pelvic fat (1.62 vs 2.04 %; p=0.0673) and reduce the incidence of adipose tissue in the hind leg (7.65 vs 9.13 %; p=0.0120). The meat from FSF lambs showed a more intense yellow colour (7.90 vs 6.38; p=0.0273) and a lower intramuscular fat content (47.0 vs 61.0 g/kg; p=0.0186). The diet influenced meat fatty acid (FA) profile, confirming the effect of CT from FSF in limiting the ruminal biohydrogenation of ingested unsaturated FA. Indeed, the FSF diet increased the beneficial rumenic acid (1.58 vs 1.02 % FA; p=0.0197) and trans-vaccenic acid (1.95 vs 0.69 % FA; p<0.0001). In triangle tests, no sensory difference related to diets was perceived in meat. The results highlight the effects of FSF in reducing carcass and meat fatness and improving the intramuscular FA profile.