Feasible feeding strategies for sustainable management of serve heat stress conditions: Effect of Milk Thistle extract on growth performance and health status of newly weaned rabbits.

The trail aimed to explore the effect of dietary supplementation of Milk Thistle (MT) extract on growth performance and health status of growing rabbits exposed to serve heat stress condition, considering the economic efficiency of supplementation. A total of 96 weaned male rabbits were divided into 4 groups (24 rabbits/group). The first group received the basal diet without any supplementation and served as a control (MT0), while 2nd, 3rd and 4th groups supplemented with MT at levels of 5 (MT5), 10 (MT10) and 15 (MT15) g/kg diet, respectively, for 10 consecutive weeks. Both of growth performance and feed utilisation were significantly enhanced by the dietary treatment, the optimum dose of MT was 12 g/kg diet for average daily gain, specific growth rate and performance index. However, it was 13 g/kg diet for feed conversation ratio. The polynomial regression analysis showed that the lowest values of rectal temperature and respiration rate were observed at doses of 11 and 13 g/kg diet respectively. The dressing percentage and the relative weights of liver and total edible giblets were significantly improved by the treatment (p = 0.0416, 0.0112 and 0.0032, respectively), maximising in the MT10 group. The MT10 and MT15 groups showed higher erythrocytes and leucocytes counts and lower levels of urea, creatinine and total cholesterol compared to the control (p < 0.05). Liver functions significantly enhanced in aforementioned two treated groups, the liver ultrastructure represented normal cytoplasmic organelles, and nucleus and mitochondria in MT10 group, while the MT15 group showed hepatocytes with dilated nucleus with most cytoplasmic organelles appeared well organised and normal except few small cytoplasms vacuolated. The levels glutathione, superoxide dismutase, catalase and total antioxidant capacity as well as immunoglobulin M, and immunoglobulin G significant improved in the MT-Treated groups compared to the control (p < 0.05). Economically, MT supplemented diets improved the net revenue of fattened rabbits during the summer season. In conclusion, the supplementation of MT extract at levels of 10 or 15 g/kg diet enhanced growth performance, feed utilisation, dressing percentage, hemato-biochemical attributes, immunity and redox balance of heat stressed growing rabbits during the hot season.

The benefits of Maca (Lepidium meyenii) extract administration for male rabbits affected by environmental heat stress.

Heat stress (HS) is the most substantial environmental issue in rabbit health status impairment, which can lower productivity. Maca is a common medicinal plant with important biological activities including antioxidant, anti-inflammatory, anti-fatigue, and neuroprotective effects. The present research explored the alleged protective role of Maca extract in alleviating the adverse impact of HS on rabbits. Growing V-line 6-week-old buck rabbits (N = 48) were orally administered Maca extract at levels of 0 (MAC0), 200 (MAC2), 400 (MAC4), or 600 (MAC6) mg/head twice per week. Compared to the control groups, rabbits provided Maca had better growth performance, feed intake and feed conversion ratio. Liver and tests weights were significantly higher (p < 0.05) in Maca treated groups compared to the control. hemoglobin, white blood cell, red blood corpuscles, platelet count, hematocrit, and lymphocytes were significantly increased in the MAC4 group compared with the control group. MAC4 treatment significantly reduced aspartate aminotransferase and malondialdehyde levels compared with other groups. Moreover, the concentrations of total bilirubin, creatinine, glucose, total cholesterol, and triglycerides were lower (p < 0.05) in the MAC4 group than in the controls. Oral administration of Maca improved cortisol and testosterone values, total antioxidant capacity, and superoxide dismutase. The MAC4 group exhibited significant improvement (p < 0.05) in sperm motility, survival, membrane functionality, concentration, and libido, with a significant decrease in abnormal sperm compared with the control group. Also, aforementioned group showed sperm cells with a normal structure and intact plasma membranes, acrosomes, and well-organised axonemal components. Histopathological screening of liver sections showed moderate to severe degenerative and necrotic changes in rabbits exposed to HS, which were alleviated with Maca oral administration. In conclusion, oral administration of Maca extract at 400 or 600 mg/head-weekly enhanced growth performance, hemato-biochemical attributes, antioxidant status, and semen quality in rabbits during the hot season.