Efficacy of Rumex nervosus leaves or Cinnamomum verum bark as natural growth promoters on the growth performance, immune responsiveness, and serum biochemical profile of broiler chickens

This study was conducted to evaluate the potential growth and health promotion of Rumex nervosus leaves (RNL) and Cinnamomum verum bark (CVB) supplementation as phytogenic growth promoters on broilers. For 34 days, 540 day-old broiler chicks were randomly assigned to nine groups. Birds were fed the basal diet supplemented with 1, 3, or 5 g/kg RNL, 2, 4, or 6 g/kg CVB. In addition, birds were fed the basal diet complemented with antibiotic (AGP), or basal diet without feed additive as controls. All bird vaccinated for IBV, IBDV, and NDV except negative control (NC). The selected indicators were measured and analysed. Broilers given 1 g RNL were numerically heavier at 34 days and gained more to a degree comparable to the AGP group (p = .053). The addition of CVB at 2 g resulted in the best-feed conversion up to 21 d (p = .04). Throughout the study, dietary treatments had no impact on feed intake. Except for ALT, none of the immune-related parameters or serum biochemical profile differed statistically between treatments when compared to vaccinated control group. When comparing the non-vaccinated un-treated group on day 34, vaccination increased significantly antibody titres to NDV and IBDV. In conclusion, dietary RNL and CVB, especially at low doses, attempted to maximise the performance without compromising health in broiler chickens under typical conditions. Further research into the use of natural herbs under challenging conditions is required to maximise performance, maintain animal productivity, and achieve the ultimate goal of reducing antibiotic use in the poultry industry. Highlights Cinnamomum verum bark at a dose of 2 g/kg diet improved feed conversion ratio during the starter period. However, both selected herbs result unsatisfactory improvements in broiler performance at overall period under the ideal hygienic conditions. If broilers are exposed to bacterial challenges, phytogenic feed additives or even antibiotics may manifest their activity in promoting animal health and, as a result, growth performance. Low levels of hepatic enzymes at day 34 of age showed that birds’ health was good. Cinnamon powder improves kidney function at day 21 by lowering serum creatinine levels with increasing dose (p < .05). Rumex nervosus leaves or Cinnamomum verum bark have hypoglycaemia activity on day 31 by lowering serum glucose levels as the dose is reduced.