Combination of phytotherapic components (cinnamaldehyde, carvacrol, thymol) and butyric acid in broiler feed: impact on performance parameters, hematology, meat quality, microbiota, and intestinal morphology

Abstract

Concern about food safety, as well as the impact of chemical residues from food on human health has gradually increased in recent years, causing the animal production industry to seek significant solutions and undergo major transformations. The prolonged use of antibiotics in animal feeding can cause risks to the health of consumers, since residues of the same can be found in products of animal origin intended for consumption by population, or even cross-resistance with other antimicrobials used in human or animals' therapy. Therefore, studies of new additives growth promoters that favor the intestinal microbiota are needed to replace the use of antibiotics. Thus, the aim of this study will be to evaluate the effect of essential oils and butyric acid isolated and/or associated on zootechnical performance, intestinal morphometry, organs weight, hematology, serum biochemistry, meat quality and oxidative status, small intestine injury score, in addition to characterizing, by PCR, the microorganisms present in the intestinal microbiota of broiler challenged with coccidiosis vaccine. For this, a study will be conducted with 900 one- day-old male broiler chickens, distributed in DIC, with six treatments of five replicate pens: T1 - not challenged birds, basal diet (BD) (corn-soybean based diet); T2- challenged birds (C), BD; T3-C, BD with avilamycin inclusion; T4-C, BD with inclusion of cinnamaldehyde, carvacrol and thymol; T5-C, BD with inclusion of butyric acid glycerides; T6-C, BD with inclusion of cinnamaldehyde, carvacrol and thymol + butyric acid glycerides. At 14 days of age, chicks (T2 to T6) will be orally challenged with coccidiosis vaccine. Performance data will be collected for cumulative periods from 1 to 21, 1 to 35, and 1 to 42 days of age. At 21 and 35 days of age, segments of the duodenum and jejunum will be collected for morphometric analysis and obtained data on organ weight, length of the small and large intestines, and intestinal content pH. At these same ages, 3mL of blood will be collected for serum and immunological analysis and, the breasts will be collected for analysis of meat quality and oxidative status. At 21 days of age, intestinal samples from five birds/treatment will be collected for analysis of the microbiota present in the gastrointestinal tract of chickens. Before vaccination and at 4, 5, 6, 7, and 14 days after vaccination, excreta samples from each experimental unit will be collected to count oocysts. At 3, 5, 7, 9, 11, and 14 days after vaccination, the scores of lesions in the small intestine of 10 birds/treatment will be evaluated. To evaluate the quality of the litter, the pH, temperature, and humidity will be measured at 14, 21, 28, and 35 days of age. The data will be submitted to ANOVA by the GLM procedure and, when there is a significant effect, the means will be compared by the Tukey test with 5% of significance. (AU)