The current study was performed to evaluate the effects of the dietary inclusion of extra virgin olive oil (EVOO), betaine (BET), lemongrass essential oil (LGEO), gallic acid (GA), vitamin C (VC) and vitamin E (VE) on different body temperature traits and stress hormone and glucose levels in heat-stressed growing rabbits. Rabbits were fed diets with no supplementation (control group) or supplemented with 15 g of EVOO, 400 mg of LGEO, 500 mg of GA, 1000 mg of BET, 500 mg of VC, or 200 mg of VE per kg of diet. All tested feed additives, especially EVOO, had a lowering effect on various rabbit temperature traits. Both triiodothyronine (T3) and tetraiodothyronine/thyroxine (T4) were increased (p<0.05) by the addition of BET, VC, EVOO, and VE. With the exception of the VC group, all dietary groups showed no significant changes in the insulin level compared to the control group level. In contrast, the cortisol and glucose levels were diminished (p<0.05) in all treated groups compared to the control levels. The results suggested that all tested supplementations had positive ameliorating effects on growing rabbits under a severe heat load in terms of lowered body temperatures and a favourable stress hormone balance, with the most favourable results found in the EVOO, VC, and BET supplementation groups.

This study explored the effects of supplemental dietary extra virgin olive oil (EVOO), gallic acid (GA), or lemongrass essential oil (LGEO) on growth performance, nutrient digestibility, carcass traits, lipid peroxidation, hematological, and antioxidative status in growing rabbits under heat stress conditions. A total of 48 male growing New Zealand White rabbits were randomly divided into four equal groups, which received a basal diet without any supplementation or supplemented with 15 g EVOO, 500 mg GA, or 400 mg LGEO/kg of diet, for eight consecutive weeks. Results revealed that the overall mean of temperature humidity index was 84.67 ± 0.35, reflecting a state of severe heat stress. Moreover, dietary supplementation with EVOO, GA, or LGEO significantly increased live body weight and daily body weight gain but decreased both feed conversion ratio and daily water consumption. Additionally, a significant increase in both organic matter and crude protein digestibility besides a remarkable elevation in the nutritive values of digestible crude protein, total digestible nutrients, and digestible energy, as well as an increase in the numbers of WBCs, lymphocytes, and heterophils was significant in EVOO-supplemented rabbits. Supplementation with EVOO, GA, or LGEO in the heat-stressed growing rabbit's diet enhanced catalase activity and reduced glutathione content, whereas EVOO-treated rabbits had the highest values. Also, malondialdehyde activity was reduced in response to all tested additives. In conclusion, these findings suggested that addition of EVOO, GA, or LGEO in growing rabbit's diet could be used effectively to alleviate negative impacts of heat stress load on performance, nutrient digestibility, oxidative status, and hemato-biochemical features. Furthermore, among these additives, EVOO achieved the best effects.

No abstract

An electric model created by Simulink/Matlab is used to describe the main characteristics of a plasma dielectric barrier discharge (DBD) at atmospheric pressure under a flow of helium gas. The model is based on a voltage controlled current source and a variable gap capacitor. The applied voltage, the corresponding current, gap voltage and dielectric voltage are the main characteristic investigated in the present work. The applied sinusoidal voltage to the electrodes is generated by an induction coil transformer at 5.7 kHz. Experimental measurements are made to extract some DBD parameters and validate the model results.

An 8-week experiment was carried out to assess the impact of supplemental dietary pyridoxine (PY), protease (PR), zinc (Zn) and their mixture (MIX) with low protein diet (LP; 14.76% CP) or high protein diet (HP; 18.53% CP) on rabbit growth, feed utilization, and nutrients digestibility. Rabbits were divided into ten similar groups in a 2 (protein level) ×5 (treatments) factorial design. Treatments included a control group (without any additives), 5 mg PY/kg of diet, 100 mg Zn/kg of diet, 500 mg PR/kg of diet or a mixture of all tested feed additive with the same doses. Results indicated that growth performance, feed utilization, and nutrients digestibility indicators were retarded significantly with reduction of dietary crude protein. Growth performance and feed conversion were significantly enhanced as a result of PY, PR, Zn, and MIX supplementation. All feed supplements had significantly improved the digestibility of crude protein and digestible crude protein. No change in carcass traits was recorded in response to protein level and tested feed supplements. It is concluded that the growing rabbit responded positively to PY, Zn, PR, and MIX (particularly PY) supplemental of LP or HP diets, in terms of growth performance, feed conversion, and nutrient digestibility.