Growth performance, carcass characteristics and meat quality of male goat kids supplemented by alternative feed resources: Olive cake and cactus cladodes

The current study was carried out to evaluate the effect of olive cake and cactus cladodes incorporation on growth performance, carcass characteristics and meat quality of goat kids. Forty-eight male goat kids were divided into four groups. The control group received a conventional diet and the test groups received, on dry matter basis, 200 g/kg of olive cake (OC), 160 g/kg of cactus cladodes (CC), or 80 g/kg OC and 80 g/kg CC (OC + CC) respectively. During the experiment, the dry matter intake (DMI) and the average daily gain (ADG) were determined. At the end of the trial, all animals were slaughtered and the carcass quality was characterized. Samples of longissimus dorsi and semimembranosus were collected to determine meat quality. The diets did not affect DMI, ADG, final body weight and carcass characteristics, except for muscle index that decreased with 200 g/kg OC, and redness and yellowness at tail outline and belly (P < 0.05). The OC incorporation increased yellowness at tail and decreased redness at belly (P < 0.05), while the CC inclusion decreased redness at tail outline (P < 0.01), and redness (P < 0.05) and yellowness at belly (P < 0.01). Meat ultimate pH, color, moisture and tenderness were not affected by diets. In longissimus dorsi, higher protein (P < 0.001) and lower fat and ash (P < 0.05) content were observed with CC, and lower protein content with OC and OC + CC (P < 0.001). In semimembranosus, a low initial pH (P < 0.05) was observed with OC and high water retention capacity (P < 0.001) with CC and OC + CC. Generally, groups, ratios, and indexes of fatty acids (FA) were similar between groups, except the FA profile that was affected by diet, especially for semimembranosus. In longissimus dorsi, the OC and CC introduction decreased C16:1, and C20:3n-3 increased with CC and OC + CC (P < 0.05). While in semimembranosus, OC increased C6:0, C8:0, C18:3n-3, C20:2, and C22:2, whereas CC incorporation reduced C8:0, C10:0, and C15:1, and OC + CC reduced C10:0 (P < 0.05). Overall, OC and CC showed a lack of negative effects on growth performance, carcass characteristics and meat quality. Thus, they could be introduced in goat kids' diet to reduce supplement charges.