The aim of this research is to evaluate the influence of antibiotics in early development of gut microbiota, immune response and impact of diarrhea in newborn calves. For this purpose, 20 healthy Holstein calves will be used, divided in two groups with 10 animals each: group 1: will receive Florfenicol antibiotic (20mg/kg) at birth and group 2: will not receive antibiotics. Calves will be examined under general and specific clinical examination of systems. Then, blood samples and feces will be collected at the following moments: before colostrum intake (M0); 1-3 (M1); 4-6 (M2); 7-9 (M3); 10-12 (M4); 13-15 (M5); 20-25 (M6); and 25-30 days after birth. Swabs will also be used to collect secretions from rectal mucosa. The innate immune response will be evaluated by the following tests: white blood cell count, determination of blood neutrophils (CH138) proportion and its activation by L-selectin (CD62L) expression, haptoglobin dosage and production of reactive oxygen species. The titer of antibodies specific for Escherichia coli in serum and intestinal mucosa by immunoenzymatic test will be performed in-house. The major fecal anaerobes and aerobes microorganisms will be determined by polymerase chain reaction in real time (qPCR). The parameters will be tested by your distribution by the Shapiro-Wilk test, opting for appropriate statistical tests.Key-words: cattle, newborn, fecal score, antibiotics.
News published in Agência FAPESP Newsletter about the scholarship: