Abstract
This study investigated the dietary effect of incorporating different levels of olive cake (OC) on the metabolic responses, growth performance, and carcass characteristics of black goat male kids. Thirty kids (body weight = 17.3 ± 0.40 kg) were randomly distributed into one of three equally sized dietary groups: a control diet (CON), OC at 75 g/kg (OC75), and OC at 150 g/kg (OC150) of dietary dry matter (DM). The results revealed that the intake of DM, crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) was similar (p ≥ 0.11) among the three treatment groups. However, the OC150 group had the greatest (p < 0.0001) ether extract (EE) intake compared to the OC75 and CON groups. The growth measurements were similar (p ≥ 0.13) among the three groups. Feed efficiency was not affected by the inclusion of OC. In contrast to the CON diet, the cost of gain was, however, reduced (p = 0.004) in the OC diets. All three treatment groups' digestibility of DM, CP, and ADF was similar. However, when compared to the OC75 and CON groups, the digestibility of NDF was better (p < 0.05) in the OC150 group. The N intake did not differ among the three experimental groups. Nitrogen retained as g/d was higher (p = 0.04) in the OC150 and OC75 groups compared to the CON group, while retention as a percentage (g/100 g) was similar among the three groups. Except for intermuscular fat, total fat, leg fat depth, and tissue depth, the inclusion of OC did not result in any discernible treatment effects on the carcass and meat quality parameters. Only alanine aminotransferase enzyme activity was lower (p < 0.0001) in OC-treated groups compared to the CON group. In summary, incorporating OC at 75 g/kg and 150 g/kg levels into the diets of black goat kids had positive comparable effects on some parameters related to growth performance, carcass attributes, and meat quality. Importantly, utilizing olive cake led to cost savings in production and may serve as a viable alternative feed source in goat nutrition.