Extrato de orégano (origanum vulgare) em frangos de corte machos de linhagem caipira criados na amazônia ocidental

Abstract

The aim of this study was to evaluate the effect of oregan extract associated with growth promoter on performance, carcass yield, intestinal morphometry, intestinal pH and leukogram of free-range broilers. Three hundred sixty "heavy red" lineage chicks were used distributed using a completely randomized design with 5 treatments x 6 replications, submitted to sanitary and environmental challenge. The control treatment included basal diet (BD) and growth promoter. Oregano extract (OE) was added at different levels in the other treatments: BD without extract; BD+150 mg/kg de OE; BD+250 mg/kg de OE; BD+350 mg/kg de OE e BD+450 mg/kg de OE. There was a significant effect on feed intake and feed conversion. In weight gain and viability there was no difference. There was no effect on carcass and offal yield, as well as on the intestinal pH value. There was a change in the heterophile/lymphocyte ratio and also in intestinal morphometry. The inclusion of the additive positively influenced some productive characteristics, highlighting the treatments with 350 mg/kg and 450 mg/kg as more efficient.