Performance and meat quality of growing rabbits fed diets including Chlorella vulgaris

The present study aimed at evaluating the growth performance, diet digestibility, and meat quality of growing rabbits fed diets with different levels of chlorella (Chlorella vulgaris) and fat. A total of 576 mixed-sex crossbred rabbits (841 ± 140 g live weight; 33 days of age) were randomly distributed in 72 pens with 8 animals and assigned to six experimental groups according to a bi-factorial arrangement consisting of three dietary inclusion levels of chlorella (0%, 1%, and 2%) and two levels of crude fat (CF: 3.0% and 5.0%). The six diets were formulated to be isonitrogenous (15.5% crude protein) with two levels of DE (9.48 and 9.98 MJ/kg) according to CF level. Individual live weights were recorded weekly; pen feed intake and rabbit health status were monitored daily. From 47 to 51 days of age, a digestibility trial was performed. At 71 days of age, the rabbits were slaughtered and their meat burgers analysed for proximate composition and fatty acid profile. Growth performance of rabbits was not affected by the dietary treatments, whereas feed conversion improved by 5% as CF increased (P<0.001). Diets with 2% chlorella decreased the digestibility of CF. Diets with 5% CF improved the digestibility of dry matter, hemicelluloses, CF and gross energy. As for meat quality, the inclusion of 2% chlorella increased the proportion of n-3 polyunsaturated fatty acids and the n-3/n-6 ratio in meat burgers. Overall, the inclusion of chlorella up to 2% in the diets for growing rabbits did not affect rabbit performance, whereas slightly improved the quality of the meat products in terms of fatty acids profile.