Dietary supplementation with Lauraceae and Chlorellaceae in growing rabbits: effects on meat quality parameters

In recent years, following the official ban on growth promoters, there has been a significant shift in research towards using dietary natural substances to support animal health and performances. The present study evaluated the effects of Laurus nobilis leaves (LAU) and Chlorella vulgaris (CHLO) dietary supplementation in rabbits on meat quality parameters. The trial was conducted at the National Agricultural and Food Centre (Luzianky, Slovak Republic) on 75 weaned New Zealand rabbits (35 days old, average body weight 1.1 kg), randomly divided into three groups: the control group (CTR) received a commercial pellet diet, the CHLO group received the same diet supplemented with 0.1% dried Chlorella algae powder and the LAU group received the control diet supplemented with 0.1% dried bay leaves powder. After 60 days, rabbits were slaughtered at about 2.8 kg of live weight and Longissimus dorsi (LD) muscles were collected (10 animals per treatment) for determination of meat quality parameters. The chemical composition and the fatty acid composition were determined using the Fourier Transformed Infrared Spectroscopy (FT-IR) method. No differences (P>0.05) in dry matter, protein and ash content were observed. The ether extract of LD muscle resulted lower (P<0.001) in CHLO (0.70 ± 0.04%) than in CTR (0.94 ± 0.04%) and LAU (0.94 ± 0.05%) groups. The LD muscle fatty acid composition was influenced by dietary treatments. The LAU group showed a higher percentage (P<0.05) of saturated (36.2 ±0.21 CTR vs 37.1 ± 0.10 LAU vs 36.5 ± 0.15 CHLO), monounsaturated (37.4 ±1.85 CTR vs 44.3 ± 0.25 LAU vs 36.6 ± 1.8 CHLO), polyunsaturated (6.8 ± 0.19 CTR vs 7.6 ± 0.25 LAU vs 6.7 ± 0.29 CHLO) and omega 6 fatty acids (6.2 ± 0.19 CTR vs 7.0 ± 0.24 LAU vs 6.0 ± 0.29 CHLO) compared to the CTR and CHLO groups. Omega-3 fatty acids (P<0.05) were higher in both CHLO (0.53 ± 0.01) and LAU (0.51 ± 0.01) groups than in CTR (0.48 ± 0.01). The health-promoting atherogenic and thrombogenic indices were lower in the LAU group than the other two experimental groups. Supplementation with Chlorella vulgaris powder affected the fat content of the meat. Laurus nobilis had a positive effect on the fatty acid composition of the LD muscle, enhancing its health benefits. Further studies are required to confirm the present data and evaluate the effect of these supplements on meat sensory profile. Research supported by the Slovak Research and Development Agency, Contract No. APVV-20-0037.