Organic acids, essential oils and symbiotic in semi-heavy laying hen diets: productive performance and economic analysis

This experiment was carried out in order to evaluate the effects of organic acids, essential oils and symbiotic as antimicrobial (growth promoters) replacements on performance, egg quality and economic viability of semi-heavy laying hens production. A total of 240 Hy-line Brown layers hens at 32 weeks of age and with an average weight of 1.650 ± 0.034kg were distributed in a completely randomized design with four treatments containing six replicates each one. The experiment lasted 140 days and was divided into five periods. The following treatments were employed: treatment 1 - negative control (without growth promoter); Treatment 2 - positive control (with growth promoter - virginiamycin); Treatment 3 - basal ration + organic acids + essential oils; and treatment 4 - basal ration + symbiotic. There were no significant effects of treatments on the variables feed intake, egg production, egg weight, egg mass, conversion by egg mass, and conversion per dozen eggs (Pu003e0,05). It was concluded that the combination of organic acids, essential oils and symbiotic can replace growth promoters without changing the performance and quality of semi-heavy laying eggs. The use of symbiotic in diet provide a higher gross margin when compared to the other treatments.