Substituting alfalfa hay with pomegranate and olive leaves in diet of growing kids: Effects on performance, antioxidant status, carcass traits, and meat quality

چکیده مقاله

This study investigated the effects of replacing alfalfa hay (AH) with pomegranate leaves (PL), olive leaves (OL), or their 50:50 mixture on growth performance, antioxidant status, carcass traits, and meat quality of growing kids. Twenty-eight male Saanen kids [initial body weight (IBW) 16.4 ±2.6 kg, three months of age] were randomly allocated to four dietary groups: (1) CTRL: control diet with 15% AH (DM basis), (2) PL: AH fully replaced with PL, (3) OL: AH fully replaced with OL, and (4) PL + OL: AH fully replaced with a 1:1 mixture of PL and OL. Individual dry matter intake (DMI) was recorded daily and kids were weighed on days 0, 15, 30, 45, and 60. Blood samples were collected on days 0, 30, and 60. At the end of the trial, kids were slaughtered for carcass and meat evaluation. No diet effects were observed on DMI (p = 0.566), final body weight (FBW, p = 0.857), average daily gain (ADG, p = 0.597), and feed conversion ratio (FCR, p = 0.400). Blood biochemical parameters remained largely unaffected, although a tendency for reduced cholesterol (CHOL, p = 0.075) and increased high-density lipoprotein (HDL, p = 0.097) was noted in kids fed diets containing PL and/or OL. Furthermore, blood total antioxidant ca pacity (TAC, p < 0.001) and the activities of glutathione peroxidase (Gpx, p < 0.001) and su peroxide dismutase (SOD, p = 0.016) were higher in the PL, OL, and PL/OL groups compared to CTRL, while malondialdehyde (MDA) concentration was lower (p =0.085). Also, meat TAC tended to increase in the PL, OL and PL/OL groups (p = 0.08). Meat lightness (L*) was higher in PL and OL groups compared with CTRL (p = 0.022) while redness (a*) was unaffected (p = 0.445). The lowest yellowness (b*) was observed in the group receiving the PL/OL diet (p = 0.035). Overall, replacing 15% DM of the diet with PL, OL, or their 50:50 mixture had no adverse effect on growth performance, while improving blood antioxidant parameters and meat antioxidant capacity in growing kids.