Blend of cinnamaldehyde and diallyl disulfide associated or not to antibiotics on ruminal fermentation, cortisol and blood metabolites of feedlot steers fed no-forage diet

ABSTRACT

The objective of this study was to evaluate the effects of an essential oil blend (EO), based on cinnamaldehyde and diallyl disulfide, associated or not with antibiotics on intake and nutrient digestibility, ingestive behavior, rumen fermentation, ruminal microbial synthesis, and blood metabolites of feedlot cattle fed a no-forage diet. The study was carried out as a Latin Square with five treatments consisting of a blend of essential oil (EO), monensin (MON) and virginiamycin (VM), both separately and combined as follows: CON (monensin at 30 mg kg^–1 DM), VM (virginiamycin at 25 mg kg^–1 DM and monensin at 30 mg kg^–1 DM), MEO25 (monensin at 30 mg kg^–1 DM and EO at 25 mg kg^–1 DM), MEO35 (monensin at 30 mg kg^–1 DM and EO at 35 mg kg^–1 DM) and EO35 (blend of EO at 35 mg kg^–1 DM). There were no effects from additives and their combinations on the intake and apparent digestibility of nutrients or ingestive behavior. Furthermore, treatments did not modify the ruminal pH, nor the concentration of short-chain fatty acids and ammonia, nor the microbial protein synthesis. Blood glucose concentration was higher 4 h after morning feeding for all treatments. There was a significant contrast between the VM and EO for the blood concentration of D-Lactate and L-Lactate. There was no difference between the additives in the concentration of cortisol metabolites in the feces. The blend of essential oil studied, containing cinnamaldehyde and diallyl disulfide, associated or not with antibiotics, does not change the nutritional parameters nor the metabolism of feedlot cattle fed a no-forage diet.

cinnamaldehyde; diallyl disulfide; feedlot; starch