Susceptibility of dairy cows to subacute ruminal acidosis is reflected in both prepartum and postpartum bacteria as well as odd- and branched-chain fatty acids in feces

Hong Yang; Stijn Heirbaut; Xiaoping Jing; Nympha De Neve; Leen Vandaele; Jeyamalar Jeyanathan; Veerle Fievez

doi:10.1186/s40104-022-00738-8

Susceptibility of dairy cows to subacute ruminal acidosis is reflected in both prepartum and postpartum bacteria as well as odd- and branched-chain fatty acids in feces

J Anim Sci Biotechnol. 2022 Oct 5;13(1):87. doi: 10.1186/s40104-022-00738-8.

Authors

Hong Yang¹, Stijn Heirbaut¹, Xiaoping Jing^{1

2}, Nympha De Neve¹, Leen Vandaele³, Jeyamalar Jeyanathan¹, Veerle Fievez⁴

Affiliations

¹ Laboratory for Animal Nutrition and Animal Product Quality, Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Campus Coupure, building F, 1st floor, Coupure Links 653, 9000, Ghent, Belgium.
² State Key Laboratory of Grassland and Agro-Ecosystems, International Centre for Tibetan Plateau Ecosystem Management, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
³ Animal Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food, Scheldeweg 68, 9090, Melle, Belgium.
⁴ Laboratory for Animal Nutrition and Animal Product Quality, Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Campus Coupure, building F, 1st floor, Coupure Links 653, 9000, Ghent, Belgium. Veerle.Fievez@UGent.be.

Abstract

Background: The transition period is a challenging period for high-producing dairy cattle. Cows in early lactation are considered as a group at risk of subacute ruminal acidosis (SARA). Variability in SARA susceptibility in early lactation is hypothesized to be reflected in fecal characteristics such as fecal pH, dry matter content, volatile and odd- and branched-chain fatty acids (VFA and OBCFA, respectively), as well as fecal microbiota. This was investigated with 38 periparturient dairy cows, which were classified into four groups differing in median and mean time of reticular pH below 6 as well as area under the curve of pH below 6. Furthermore, we investigated whether fecal differences were already obvious during a period prior to the SARA risk (prepartum).

Results: Variation in reticular pH during a 3-week postpartum period was not associated with differences in fecal pH and VFA concentration. In the postpartum period, the copy number of fecal bacteria and methanogens of unsusceptible (UN) cows was higher than moderately susceptible (MS) or susceptible (SU) cows, while the genera Ruminococcus and Prevotellacea_UCG-001 were proportionally less abundant in UN compared with SU cows. Nevertheless, only a minor reduction was observed in iso-BCFA proportions in fecal fatty acids of SU cows, particularly iso-C15:0 and iso-C16:0, compared with UN cows. Consistent with the bacterial changes postpartum, the lower abundance of Ruminococcus was already observed in the prepartum fecal bacterial communities of UN cows, whereas Lachnospiraceae_UCG-001 was increased. Nevertheless, no differences were observed in the prepartum fecal VFA or OBCFA profiles among the groups. Prepartum fecal bacterial communities of cows were clustered into two distinct clusters with 70% of the SU cows belonging to cluster 1, in which they represented 60% of the animals.

Conclusions: Inter-animal variation in postpartum SARA susceptibility was reflected in post- and prepartum fecal bacterial communities. Differences in prepartum fecal bacterial communities could alert for susceptibility to develop SARA postpartum. Our results generated knowledge on the association between fecal bacteria and SARA development which could be further explored in a prevention strategy.

Keywords: Fecal bacterial community; Fecal odd- and branched-chain fatty acids; Inter-animal variation; Subacute ruminal acidosis.

Abstract

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