Oral supplementation of the diet of growing rabbits with a newly developed mixture of herbal plants and spices enriched with special extracts and essential oils affects their productive performance and immune status

Abstract

This study aimed to evaluate the effect of feeding a mixture of herbal plants and spices enriched with special extracts and essential oils (phytogenic additives mixture) on feed intake, feed utilisation, blood chemistry, slaughter characteristics and caecal bacteria profile in rabbits. Ninety weaned unsexed V-Line rabbits, weighing 668.7 ± 8.2 g and aged 30 ± 1 days, were randomly allocated to three groups of 30 rabbits each and fed a basal diet without additives (Control rabbits) or supplemented with 0.5 mL (LA) or 1 mL (HA) of the additives mixture per litre of drinking water. Additives did not affect feed intake; however, the LA rabbits showed greater (P<0.001) feed conversion ratio compared to the other treatments. The LA treatment increased (P<0.01) final body weight and average daily gain compared to the control and HA treatments. Both the LA and HA treatments decreased (P<0.05) blood cholesterol, triglycerides and low-density lipoproteins; however, the LA treatment increased (P<0.05) high-density lipoproteins and total antioxidant capacity but decreased malondialdehyde (P<0.05) relative to the control treatment. Treatments did not affect carcass characteristics. The LA treatment followed by HA treatment increased (P<0.001) beneficial Lactobacillus spp. bacteria and decreased the concentrations of coliform bacteria and E. coli compared with the control treatment. It is concluded that additives mixture enhanced feed conversion and daily gain and positively altered caecal bacteria profile, with better effects of the low dose of the phytogenic additives mixture compared with the high dose.