Evaluation of selective dry cow therapy for prevention and treatment of mastitis and milk microbiome in Holstein dairy cows

• Grant number: 15/15208-1
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: December 10, 2015
• End date: July 24, 2016
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Vera Lúcia Mores Rall
• Grantee: Erika Carolina Romão Bonsaglia
• Supervisor: Fabio Soares de Lima
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Institution abroad: University of Illinois at Urbana-Champaign, United States
• Associated to the scholarship: 13/18338-8 - Clonal diversity and molecular characterization of Staphylococcus aureus isolated from milk of cows with subclinical mastitis in the state of Sao Paulo., BP.DR

Abstract

The dry period is a critical period for dairy cows on which animals are recovering from the last lactation and preparing for the next. In this period, the cow is not milking and pathogens present in the mammary gland are not removed increasing the odds for multiplication and development of intramammary infections. Therefore, a common practice in dairy operations is to use antimicrobials to treat unapparent infections and prevent new intramammary infections. However, this important prophylactic measure is used indiscriminately contributing to the emerging as critically important problem of antimicrobial resistance genes and microbe's development. Therefore, there is a critical need for the elaboration of surrogates measures to mitigate issues of antimicrobial resistance. Recently, petri dish that identify the major mastitis pathogens with short time turn around (16 hours) were developed offering a practical and powerful screening strategy for dairy farms. The investigation of an alternative to the current measurements of dry cow selective that targets high risk animals and the solely use of teat sealant could reduce the use antimicrobials in dairy operations. Additionally, the investigation of major antimicrobial resistance genes and microbes derived from current dry cow selective therapy needs further investigation. Therefore, the aim of this project is to determine if selective dry cow therapy based on screening with petri dish for multiple mastitis pathogens and use of teat sealant can reduce the use of use antibiotics on dairy cows without increasing new cases of intramammary infections and to evaluate the effect of selective dry cow therapy on milk's microbiome using the Shotgun Metagenomic Sequencing. (AU)