Influence of clinical mastitis caused by different pathogens on reproductive indices of dairy cows and on acute phase proteins response.

Author(s)

Felipe Morales Dalanezi

• Document type: Doctoral Thesis
• Press: Botucatu. 2019-08-30.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Medicina Veterinária e Zootecnia. Botucatu
• Defense date: 2019-08-22
• Advisor: Helio Langoni

Abstract

Bovine mastitis is responsible for major economic losses in dairy cattle farming, as well as public health aspects that should also be considered. Animals with clinical or subclinical mastitis present several reproductive alterations. In the first article of this thesis, the results showed that mastitis caused by major pathogens (20.1%) or gram-negative (15.4%) led to a decrease in pregnancy rate in the first insemination compared to the control group (32.6%). Higher gestational loss rates were observed for the major (22.2%) and gram-negative (30.1%) pathogen groups compared with the control (12.8%). The difference was observed between all groups for the number of days open. The control group had the shortest interval (126.5 days) followed by the minor pathogens group (162.0 days) and the major pathogens group (175.1 days). Similar behavior observed for gram-positive pathogens (172.7 days) and gram-negative pathogens (191.1 days). Therefore, it is important to control mastitis in dairy herds and, so, diagnosis is a critical step. Different acute phase proteins have been described as good biomarkers for the diagnosis of mastitis. In the second article of this thesis, it was observed that different pathogens may alter the release of acute phase proteins in milk. Bacteria that cause more severe inflammation (E. coli and K. pneumoniae) led to a higher concentration of APP. Pathogens causing chronic infections (Environmental Streptococcus, S. aureus, Mycoplasma spp.) led to intermediate concentrations of APP. Less severe mastitis causing microorganisms (Coagulase-negative Staphylococcus and Enterococcus spp.) led to lower concentrations of APP. Haptoglobin, AGP, and CRP showed strong, positive and significant correlations. (AU)

• FAPESP's process: 15/26055-1 - Influence of pathogens causing clinical mastitis in dairy cows reproductive indices
• Grantee: Felipe Morales Dalanezi
• Support Opportunities: Scholarships in Brazil - Doctorate