Estimation of Babesia bovis and B. bigemina infection levels in Angus and Ultrablack calves

• Grant number: 21/13849-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2022
• End date: November 30, 2023
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Genetics and Improvement of Domestic Animals
• Principal Investigator: Rodrigo Giglioti
• Grantee: Mayne Barboza Sarti
• Host Institution: Instituto de Zootecnia. Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Nova Odessa , SP, Brazil

Abstract

Bovine babesioses is a Tick-Borne Disease (TBD) that causes important damage to Brazilian cattle farming. The higher natural resistance from zebu breed to babesioses has been verified. Therefore, this study aimed to estimate the natural infections by Babesia bovis and B. bigemina in 24 Angus and Ultrablack calves (82% Angus and 18% Zebu) by Real-Time Quantitative PCR (qPCR). This proposal will be linked to the regular FAPESP process n. 2019/22675-6. Calves will be evaluated from birth to approximately 8 to 10 months of age (post-weaning). During 60 days, weekly, from each animal, blood samples will be collected for DNA and serum extraction, and the levels of tick infestation will be evaluated. After the second month, the collections will be performed biweekly until the age of 8 months to 10 months. The DNA samples will be used to estimate the infection levels of B. bovis and B. bigemina from quantifying the DNA copy number by qPCR. Serum samples will be used to evaluate the anti-B. bovis and anti-B. bigemina antibody titers. For data analysis, a multivariate model of repeated measures from the same animal will be used, including the effects of collection, genetic group, as well as the random effect of the animal. Infections (qPCR) of the two Babesia species will be contrasted between the two genetic groups, as well as tick counts and anti-babesias IgG levels. Repeatability will also be estimated from the (co)variance matrix. With the present study, it is expected the estimation of the number of copies of DNA of B. bovis and B. bigemina and the anti-babesias antibodies levels of the two genetic groups, providing reliable results for the subsequent genetic evaluations. (AU)