SUPPLEMENTAL ESSENTIAL OILS IN GROWING RABBIT DIETS

Abstract

SUMMARY his study aimed to compare the single effects of commercially available natural essential oils such as garlic oil ( Allium sativum L .), basil oil ( Ocimum basilicum ), thyme oil ( Thymus vulgaris ), and / or their combinations on growth performance, digestibility coefficients, blood lipid profile and economic efficiency of growing rabbits. One hundred - twenty male growing New Zealand White (NZW) rabbits six weeks old, with an average live body weight of 636.5±7.21g were randomly divided into eight groups (15 rabbits each). Each group was subdivided into three replicates. The 1st group (T1) was fed basal diet (16. 74% CP and 2504 Kcal/ Kg DM) free of additives and served as the control group. The 2nd group (T2) was fed a basal diet supplemented with 1 mg propylene glycol /kg diet, 3rd (T3), 4th (T4), and 5th (T5) groups were fed the basal diet supplemented with garlic oil (GO), Basil oil (BO) and thyme oil (TO) respectively, each at a dose of 400 mg/kg diet, 6th group (T6) was fed a basal diet supplemented with a combination of GO and BO at a dose of 200 mg of each oil /kg diet, 7th group (T7) was fed a basal diet supplemented with a combination of GO and TO at a dose of 200 mg of each oil /kg diet and 8th group (T8) was fed a basal diet supplemented with a combination of GO at a dose of 200 mg/kg diet, BO and TO at a dose of 100 mg of each oil /kg diet. The GO, BO, and TO oils used in this study were sprayed by 400 ml /kg diet v/w on daily pelleted feed intake to avoid loss of some volatile component of oils and to ensure the effect of essential oils in rabbit diets. The duration of the experiment was 8 weeks. The results showed that the rabbits received essential oils and their combinations showed a significant (P<0.05) increase in body weight, and daily body weight gain compared with the control group. The feed consumption showed a significant (P<0.05) increase in the T4 group compared with the control one. All experimental groups recorded a significantly improve (P<0.05) in feed conversion value compared with the control group except the T2 group. The essential oils groups and their combinations did not affect the digestibility of DM, OM, and NFE compared with the control group. The digestibility coefficient for CP, CF, and EE and nutritive values showed significant (P<0.05) higher values in T3, T4, and T6 groups compared with the control group. Results indicate that all experimental groups recorded significantly decreased (p<0.01) values of triglycerides, total cholesterol, Low-density lipoprotein cholesterol, and very low-density lipoprotein cholesterol concentration except for T2 compared with control group. An opposite effect was noticed regarding high-density lipoprotein cholesterol (HDL-c), where the values had significantly (P<0. 01) increased compared with the control group. The treatment groups recorded higher values of economic efficiency and relative economic efficiency compared to the control one. Generally, it can be noticed that the findings of this study demonstrated that dietary supplementation of essential oils and their combinations had higher body weight, better feed conversion ratio and the best economic return over the control group.