Association of Babesia bovis and B. bigemina parasitemia and feed efficiency in Nelore bulls.

• Grant number: 24/01642-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2024
• End date: April 30, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Genetics and Improvement of Domestic Animals
• Principal Investigator: Josineudson Augusto Ii de Vasconcelos Silva
• Grantee: Rafael Sartori Reis
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Babesiosis is a disease caused by the tick Rhipicephalus microplus that has a serious impact on the beef cattle industry in Brazil. Knowing the association of your incidence and feed efficiency, a relevant parameter for bull selection, it can be of great importance to improve the indices of production. However, the effect of the association of these two parameters has not yet been verified. Therefore, this project intends to verify the existence of an association between the levels of Babesia bovis and B. bigemina infections and feed efficiency in beef cattle. The study draws on data from 110 Nelore animals (Bos taurus indicus) with an average age of 550 days who participated in the 2022 feed efficiency test. The animals spent 77 days in a feedlot, including 21 days of adaptation and 56 days of testing. During the test period, the cattle were housed in four stalls equipped with troughs and electronic scales to measure weight and consumption. Blood samples were collected 28 days after the end of the adaptation period and stored at -20°C, for extraction of the genomic DNA, which will be submitted to quantitative PCR (qPCR) tests to quantify the number of DNA copies (CN). The data collected will be used to measure the quantification of CN of B. bovis and B. bigemina and animals age and residual feed intake (RFI), and will be analyzed using the stepwise regression method, with RFI as the dependent variable. The results of this study will contribute to our understanding of the association between these traits in Nelore bulls.