The Effect Of Different Dietary Levels Of Thyme Essential Oil On The Microflora And Immune Function Of Mahua Broilers

Objective：Our research was to study the effect of different levels of thyme essential oil ongrowth performance, slaughter traits, serum biochemical indexes, nutrients utilization,micro-ecological and immune status of broilers.Method：768one-day-old Mahua broilers were selected and divided into8dietary treatmentgroups，namely,0.00、0.05、0.10、0.15、0.20、0.25、0.30and0.35mg/kg with4replicatepens per treatment group(24birds each). The feeding program included a starter diet until21d and a finisher diet until42d.Results: Results showed that from0.1to0.30mg/kg essential oils of thyme couldsignificantly improve ADG from day22to42and from day1to42of broilers. From0.15to0.30mg/kg essential oils of thyme could significantly reduced F/G from day22to42ofbroilers.0.10mg/kg,0.15mg/kg essential oils of thyme could significantly reduced by6.5%F/G from day1to42of broilers.0.35mg/kg essential oils of thyme to finisher diet evisceratedrate were significantly improved18%(p=0.001).The results suggested that from0.05to0.20mg/kg,0.35mg/kg essential oils of thymemarkedly increased21d and42d serum total protein, globulin contents and alanineaminotransferase activity (P＜0.05).From0.05to0.15mg/kg,0.30mg/kg,0.35mg/kgessential oils of thyme could significantly decreased21d and42d serum urea contents(P＜0.05).0.10mg/kg,0.20mg/kg,0.25mg/kg essential oils of thyme could significantlydecreased21d and42d A/G (P＜0.05).0.10mg/kg,0.15mg/kg essential oils of thyme couldnotably improved21d and42d high-density lipoprotein.The results suggested that from0.05mg/kg to0.20mg/kg,0.35mg/kg significantlydecreased duodenal, ileal Escherichia coli, Salmonella and Lactobacillus amount.0.10mg/kgoils significantly improve the whole of crude protein, grower metabolizable energy, finisherphosphorus nutrient apparent utilization (P＜0.05).0.30mg/kg,0.35mg/kg oil groupsignificantly decreased21d phosphorus.The results showed that the ANAE+%of the supplementation of0.10、0.15、0.25、0.35mg/kg of thyme essential oils were significant against that of control group on42d. In thetreatments of0.20mg/kg,0.25mg/kg and0.30mg/kg the contents of the21st day and42ndday’s IgM,IgG and IgA can be notably improved (P＜0.05).0.25mg/kg oils significantlyimprove21d thymus Index. The ND Antibody Titre, bursal index, interleukin-1of thesupplementation of0.35mg/kg of thyme essential oils ware increased more than that of thecontrol group.Conclusion: Thyme oil can significantly improve the growth performance and meatproduction performance, improve feed; Thyme oil has antibacterial, antimicrobial, promotedigestion and absorption, enhanced protein synthesis, reduced fat deposition, improve theutilization of active substances; Thyme oil promote broilers specific immunity andnonspecific Straight immune response, activation of immune activity, improve immuneregulation. According to all the parameters, it was suggested that the essential oils add a levelof0.10mg/kg-0.20mg/kg were superior.