Differentiating between metabolic health statuses in Simmental cows and describing related milk fatty acids and relevant associated factors

Anne M Reus; Franziska E Hajek; Simone M Gruber; Stefan Plattner; Sabrina Hachenberg; Emil A Walleser; Srikanth R Aravamuthan; Rolf Mansfeld; Dörte Döpfer

doi:10.1093/tas/txad110

Differentiating between metabolic health statuses in Simmental cows and describing related milk fatty acids and relevant associated factors

Transl Anim Sci. 2023 Sep 12;7(1):txad110. doi: 10.1093/tas/txad110. eCollection 2023.

Authors

Anne M Reus¹, Franziska E Hajek¹, Simone M Gruber¹, Stefan Plattner¹, Sabrina Hachenberg², Emil A Walleser³, Srikanth R Aravamuthan³, Rolf Mansfeld¹, Dörte Döpfer³

Affiliations

¹ Clinic for Ruminants with Ambulatory and Herd Health Services, LMU Munich, 85764 Oberschleissheim, Germany.
² Deutscher Verband für Leistungs- und Qualitätsprüfungen e.V., 53113 Bonn, Germany.
³ Department of Medical Science, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706, USA.

Abstract

The aim of this observational study was to examine differences in milk fatty acid (FA) concentrations for different metabolic health statuses and for associated factors-specifically to examine with which FA concentrations an increased risk for developing a poor metabolic adaptation syndrome (PMAS) was associated. During weekly visits over 51 wk, blood samples were collected from cows between 5 and 50 days in milk. The farmer collected corresponding milk samples from all voluntary milkings. The analysis was performed on n = 2,432 samples from n = 553 Simmental cows. The observations were assigned to five different cow types (healthy, clever, athletic, hyperketonemic, and PMAS, representing five metabolic health statuses), based on the thresholds of 0.7 mmol/L, 1.2 mmol/L, and 1.4 for the concentrations of β-hydroxybutyrate and nonesterified fatty acids and for the milk fat-to-protein ratio, respectively. Linear regression models using the predictor variables cow type, parity, week of lactation, and milk yield as fixed effects were developed using a stepwise forward selection to test for significant associations of predictor variables regarding FA concentrations in milk. There was a significant interaction term found between PMAS cows and parity compared to healthy cows for C18:1 (P < 0.001) and for C18:0 (P < 0.01). It revealed higher concentrations for PMAS in primiparous and multiparous cows compared to healthy cows, the slope being steeper for primiparous cows. Further, an interaction term was found between PMAS cows and milk yield compared to healthy cows and milk yield for C16:0 (P < 0.05), revealing a steeper slope for the decrease of C16:0 concentrations with increasing milk yield for PMAS compared to healthy cows. The significant associations and interaction terms between cow type, parity, week of lactation, and milk yield as predictor variables and C16:0, C18:0, and C18:1 concentrations suggest excellent opportunities for cow herd health screening during the early postpartum period.

Keywords: metabolic health status; milk fatty acids; poor metabolic adaptation syndrome.