Supplemental Effects of Eucalyptus (Eucalyptus camaldulensis) Leaves on Growth Performance, Carcass Characteristics, Blood Biochemistry and Immune Response of Growing Rabbits

This research aimed to study the effect of dietary eucalyptus (Eucalyptus camaldulensis) leaves powder (EL) on growth performance, blood parameters, immune response and caecal microbiota in 84 growing Jabali and V-Line rabbits raised under high environmental temperature. The experiment started at 10 weeks of age and lasted 6 weeks. Rabbits were randomly distributed into three dietary eucalyptus treatments; control (no EL) and two groups supplemented with 0.1% and 0.2% EL powder. Rabbits were weighed at the beginning and at the end of the experiment. Feed intake, weight gain and feed conversion ratio were determined. Cell-mediated immune response was evaluated. At the end of the experiment, 54 rabbits were slaughtered (nine rabbits/sub-group). The results showed that the high level of EL (0.2%) had a negative effect on growth performance, dressing %, mid part % and significantly increased cell-mediated response. Rabbits fed the high level of EL showed shortening in caecum length. Significant linear reduction of total bacterial count and E. coli was observed in both groups given either 0.1% or 0.2% EL compared to the control group. Similar trend was found in the percentage of Salmonella sp. detection in both breeds. Jabali rabbits were significantly heavier than V-line rabbits and had better FCR and carcass traits except for fore part %. Additionally, they showed lower total microbial count. The current study indicated that EL could be utilized as an effective feed additive to improve cellular immunity and to reduce caecal bacterial counts in rabbits raised under high ambient temperature.