Effect of Essential Oil of Thyme (Thymus vulgaris L.) or Increasing Levels of a Commercial Prebiotic (TechnoMOS(®)) on Growth Performance and Carcass Characteristics of Male Broilers

SIMPLE SUMMARY: Since the ban of in-feed antimicrobial with auxin purposes, a wide range of herbal plants have been tested as growth promoters. In particular, thyme and prebiotic compounds, such as mannan-oligosaccharides, have been tested in animal production due to their antibacterial, antifungal, and antioxidant properties and antimicrobial, anticoccidial, and anti-inflammatory actions. Thyme essential oils and TechoMOS(®) positively affected the growth performance of Ross male broiler during the grower phase, reducing the feed intake and improving feed conversion ratio. However, increasing dose of TechoMOS(®) only affected the broiler performance on a week-to-week basis and no difference has been registered between same dosage of TechoMOS(®) and TEO. Dietary treatments, both TechoMOS(®) and TEO, did not affect the carcass characteristics at 42 days. ABSTRACT: To investigate the effect of thyme (Thymus vulgaris L.) essential oil (TEO) or increasing inclusion of a prebiotic (TechnoMOS(®)) on growth performance and carcass characteristics of Ross 308 broilers, 400 one-day-old male broilers (43.5 g, as mean of body weight) were placed in 20 pens (2.0 × 1.0 m, with a floor area of 0.10 m(2) per bird) in groups of 20, and each pen cage was assigned to a specific dietary treatment (four replicates per each one). The dietary treatments included basic diet (no additive; CTR), basic diet including 0.025%, 0.075%, or 0.125% of TechnoMOS(®) (MOS025, MOS075, and MOS125, respectively), or basic diet including 0.075% thyme extract (TEO075). All dietary treatments were offered from the beginning of the study until the end of the trial. There were no effects of MOS or TEO on carcass characteristics. No significant effects of treatment on weight gain were obtained on a week-by-week basis; however, CTR birds gained less weight during the grower phase and overall compared with MOS birds. The same contrast for feed intake revealed that CTR birds had greater feed intake than MOS birds during both the grower phase and overall (492.18 g and 486.35 g, respectively). In conclusion, treated groups showed an improved feed conversion ratio.