Effects of dietary partly destoned exhausted olive cake supplementation on performance, carcass characteristics and meat quality of growing lambs

In an experiment with 32 male growing Florina (Pelagonia) lambs, effects of replacing barley grain, sunflower meal and wheat bran with partly destoned exhausted olive cake (PDEOC) and soybean meal on productivity, carcass characteristics, meat chemical composition and meat fatty acid (FA) composition was determined. In the 56 day experiment, lambs were randomly allocated into four dietary treatments (PDEOC0, PDEOC80, PDEOC160, and PDEOC240) of 8 lambs each and accommodated in individual floor pens. Lambs had an initial body weight (BW) of 16.7 ± 1.81 kg, and were fed one of four isonitrogenous (crude protein 162 g/kg, dry matter − DM basis) and isoenergetic (net energy for gain 6.11 MJ/kg, DM basis) concentrate mixtures ad libitum and alfalfa hay (0.2 kg DM/lamb/day). The PDEOC was added to the concentrate mixture at inclusion levels (as mixed basis) of 0, 80, 160, and 240 kg/t for treatments PDEOC0, PDEOC80, PDEOC160, and PDEOC240, respectively. No differences (P > 0.05) occurred among PDEOC treatments in final BW (29.9 kg), BW gain (0.24 kg/day), DM intake (0.97 kg/day), and feed conversion ratio (4.07 kg DM intake/kg BW gain). Moreover, meat chemical composition and carcass characteristics were not affected (P > 0.05) with increased PDEOC feeding, except for the fat color, fat firmness, wetness and overall acceptability of carcasses that linearly increased with increasing PDEOC supplementation. Oleic and palmitic acids were the predominant FA in intramuscular fat of all treatments. FA were not affected (P > 0.05) with increased PDEOC feeding, except for the lauric acid which decreased (P = 0.018), as well as the α-linolenic acid which increased (P = 0.020). PDEOC supplementation, at levels up to 240 kg/t of concentrate mixtures, in isonitrogenous and iso (net energy) energetic diets for growing lambs did not affect their performance and carcass characteristics, while it improved carcass qualitative traits.