Variation in the Multivariate Relationships Between Serum Amyloid, Haptoglobin and Biochemical Profiles of Aborted and Non-Aborted Cows

Abstract

Because the time in which gestational loss or bovine abortion occurs is associated with multifactorial causes, the objective of this study was to assess multivariate relationships between the biochemical profile and acute phase proteins in aborted cows. We performed monitoring and monthly blood sampling during gestation in 140 dairy cows. A total of 18 cows aborted, which were considered ‘cases’; retrospectively, we used samples from 29 ‘control’ cows, which were taken at the same time. Thus, we compared multivariate relationships between the two groups, to evaluate variables potentially associated with cow abortion. We classified abortion as either infectious (due to DVB, leptospirosis or neosporosis) or non-infectious (protein or energetic imbalance evinced in metabolic profile). Of the 18 cows that aborted, there were 6 with evidence of positivity or seroconversion to the analysed diseases, 13 with evidence of metabolic protein imbalances, 7 with evidence of energy imbalances and 10 of them with combined situations. Case and control cows have significant differences (p<0.05) between their Principal Component Analysis (PCA), indicating that the two groups have different multivariate relationships. In aborted cows we identified a grouping of variables referring to protein metabolism asFibrinogen, Serum amyloid A, haptoglobin and titres for neosporosis and bovine viral diarrhoea virus; separated from others referring to energy and protein imbalance ashigh beta-hydroxy-butyrate, low cholesterol, low total protein. However, serum amyloid A and haptoglobin were not increased in aborted cows with clues of infectious diseases such as bovine viral diarrhoea virus, leptospirosis or neosporosis. In this way, it is evident that when the causality of abortions in a herd is studied, not only is it necessary to look for infectious diseases, but non-infectious causes can also be found occurring in parallel way. Serum amyloid A could be a candidate biomarker to differentiate a non-infectious abortion.