Combination of carbohydrases and essential oils improve dietary performance of feedlot steers on a high-energy diet

Essential oils and enzymes are alternatives to feed additives for ruminants that aim to replace the use of ionophores and improve animal performance, but their mechanisms of action are different. Therefore, the present study aimed to verify if there is a synergistic effect in the combined use of enzymes carbohydrates and essential oils on the performance, ingestive behavior and carcass traits of steers fed a high-energy diet. During the finishing period of 78 days, 40 steers were assigned to four treatments: CON- control; ENZ- enzymatic complex; EO- essential oil blend; ENZ+EO - enzymatic complex combined with essential oil blend. Regardless of the feedlot periods, the ENZ+EO treatment caused a reduction in the dry matter intake (12.48%) compared to the control. The ENZ+EO treatment resulted in the lowest mean fecal output and, consequently, the highest dry matter digestibility (DMD) and starch digestibility (SD), compared to the other treatments. Animals that received EO and ENZ+EO in the diet spent more time in feeding. As for the number of times animals visited the feeding trough, the highest values were presented by the animals in the EO, ENZ and ENZ+EO treatments. For the carcass parameters, only the subcutaneous fat thickness on the rib was significantly different between treatments, with the highest values obtained by adding EO and ENZ+EO (8.80 and 8.10 mm respectively). Thus, the combination of carbohydrate enzymes and essential oils proved to be synergistically beneficial in relation to better use of nutrients and productive performance of feedlot steers.

Essential oils of Cordia species, compounds and applications: a systematic review

The purpose of this systematic review was to identify the available literature on the essential oil from species of genus Cordia. This study followed the Preferred Reporting Items for Systematic Reviews. The search was conducted on four databases: LILACS, PubMed, Science Direct, and Scopus until June 5th, 2020, with no time or language restrictions. Sixty out of the 1,333 initially gathered studies fit the inclusion criteria after the selection process. Nine species of Cordiawere reported in the selected studies, out of which 79% of the evaluated studies reported essential oil from Cordia curassavica. The essential oil extraction methods identified were hydrodistillation and steam distillation. As for biological application, antimicrobial, anti-inflammatory, larvicidal and antioxidant activities were the most reported. The main compounds reported for essential oil were β-caryophyllene, α-humulene, α-pinene, bicyclogermacrene, and sabinene. The information reported in this systematic review can contribute scientifically to the recognition of the importance of the genus Cordia.

Chemical composition, in vitro larvicidal and antileishmanial activities of the essential oil from Citrus reticulata Blanco fruit peel

Numerous studies have investigated the chemical composition and biological activities of essential oils from different Citrus species fruit peel, leaves and flowers. This paper aims to investigate the chemical composition, larvicidal and antileishmanial activities of essential oil from Citrus reticulata fruit peel (CR-EO). CR-EO was obtained by hydrodistillation in a Clevenger-type apparatus and its chemical composition was analyzed by GC-MS and GC-FID. Limonene (85.7%), ɣ-terpinene (6.7%) and myrcene (2.1%) were identified as its major components. CR-EO showed high activity against promastigote forms of Leishmania amazonensis (IC50 = 8.23 µg/mL). CR-EO also exhibited high larvicidal activity against third instar Aedes aegypti larvae at a lethal concentration (LC50 = 58.35 µg/mL) and 100% mortality at 150 µg/mL. This study suggests, for the first time, the potential use of CR-EO against this important mosquito-borne viral disease caused by the genus Aedes.