Persistence of subacute ruminal acidosis across first and second lactations in dairy cows based on reticular pH metrics and microbiota, and systemic health responses.

ABSTRACT: The aim of this study was to determine the associations between the subacute rumen acidosis (SARA) severity in the first lactation with that in the second lactation, based on reticular pH metrics, fermentation, microbiota and systemic health variables. The experiment included 17 lactating Holstein cows (second lactation, 635 ± 56 kg BW, BCS 3.2 ± 0.2, DIM 87 ± 57 d). Cows were first fed a 40%-concentrate (LC) diet for 2 wk, then switched to a 65%-concentrate (HC) diet (DM basis) for 4 wk. While inflammation, liver health and reticular pH metrics variables were measured in all cows, ruminal and fecal fermentation and microbiota were measured only in 11 rumen cannulated cows. Data showed that the first lactation classified SARA severity type (that is, LOW or HIGH) had no effect on the second

SUBMITTER: Biber P 

PROVIDER: S-EPMC12573080 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature