A mixture of free and microencapsulated essential oils combined with turmeric and tannin in the diet of cattle in the growing and finishing phase: A new tool to enhance productivity

The study was conducted to evaluate whether adding a blend containing free and microencapsulated essential oils, combined with turmeric and tannin, can replace monensin as a performance improver, positively influencing animal health and meat quality. Fourteen male cattle with an average initial body weight of 253 kg and ten females with an average initial body weight of 239 kg were included in the experiment in a confinement system. The animals were divided into four independent groups: Males (M-PHYTO, inclusion of the phytogenic mixture; M-MONEN, inclusion of monensin); Females (F-PHYTO, inclusion of phytogenic; F-MONEN, inclusion of monensin). The diets were formulated for an average daily gain of 1.5 kg, with food provided twice daily. Data and biological samples were collected on days 33, 100, and 153. M-PHYTO and F-PHYTO showed greater average daily gain and body weight, with a tendency to consume more dry matter and feed efficiency. However, the apparent digestibility of nutrients was higher in animals in the MONEN group than those in the PHYTO group, regardless of sex. The total number of leukocytes in cattle in the M-PHYTO and F-PHYTO groups was higher due to the higher lymphocyte count in the blood of these animals. The activity of gamma-glutamyltransferase and aspartate aminotransferase in animals that consumed the phytogenic mixture was lower compared to animals that consumed monensin. TBARS levels were lower in the serum and meat of cattle in the M-PHYTO and F-PHYTO groups, as were the total thiol concentration and glutathione S-transferase activity in the blood and meat of these animals. Bacterial activity was greater in the rumen fluid of cattle that consumed the phytogenic, as demonstrated by the methylene blue reduction test. The total production of short-chain fatty acids and acetic acid showed an interaction between treatment and days for both sex classes and an effect of treatment for females, with a higher concentration in the rumen in the M-PHYTO and F-PHYTO groups. Propionic acid affected treatment and the treatment x day interaction for males and females, with the M-PHYTO and F-PHYTO groups showing higher concentrations. There was an interaction between treatment and day in the acetate/propionate ratio, being lower in M-PHYTO and F-PHYTO cattle. Treatment between ruminal microbiota groups had no effect. The rib eye area had more significant gains when consumed phytogenic by males and females. The subcutaneous and sirloin fat thicknes