231 Urinary metabotyping around parturition indicates consistent metabolite signatures that can be used for monitoring and diagnosing of subclinical mastitis in dairy cows.

Abstract

The objective of this study was to identify urinary metabolite signatures that can be used for monitoring and diagnosing of subclinical mastitis in Holstein dairy cows. Six multiparous pregnant Holstein cows with subclinical mastitis (SCM) and 20 healthy controls (CON) were selected out of 100 cows in the study. DI/LC-MS/MS-based urinary analyses were conducted on samples collected at -8, -4, SCM diagnosis, and at +4 and +8 wks around the expected day of calving. Data indicated that 14 amino acids and derivatives were found in the urine with Gln and SDMA consistently increased (P<0.005) in the urine of SCM cows. Out of 39 acylcarnitines (ACs) quantified C12:DC, C14, and C18:2, were higher (P<0.05) in SCM at all time points (P<0.05). Seventeen ACs at -8 wks, 10 at -4 wks, 23 at disease wk, 8 at +4 wks, and 12 at +8 wks were higher (P<0.05) in the urine of SCM cows. Most of the alterations regarding lysophosphatidylcholines (LPCs) were found at -8 and -4 wks prepartum with 6 and 4 LPCs species lowered at -8 and -4 wks, respectively (P<0.05). Multiple sphingomyelin (SM) species prior to calving (3 at -8 wks and 8 at -4 wks) and 2 at disease week were lowered in SCM cows (P<0.05). A total of 74 phosphatidylcholines (PCs) were measured in the urine. A total of 12, 12, 10, 9, and 9 species of PC aa and 7, 15, 15, 3, and 3 species of PC ae were altered during weeks -8, -4, Disease wk, +4, + 8 wks around calving. Overall, multiple metabolite species related to amino acids, ACs, LPCs, and PCs metabolism were identified as altered in the urine of periparturient dairy cows. Some of the most important metabolites might be used as biomarkers to screen cows for SCM.