Effects of High Concentrate-Induced Subacute Ruminal Acidosis Severity on Claw Health in First-Lactation Holstein Cows

Abstract

This study aimed to evaluate the effects of diet-induced subacute rumen acidosis (SARA) severity during transition and the early lactation period on claw health in 24 first-lactation Holstein heifers. All heifers were fed a 30% concentrate (in dry matter) close-up ration three weeks before calving, then switched to a high-concentrate ration (60% dry matter), which was fed until the 70th day in milk (DIM) to induce SARA. Thereafter, all cows were fed the same post-SARA ration with around 36% concentrate in dry matter. Hoof trimming was performed before calving (visit 1), at 70 (visit 2) and at 160 DIM (visit 3). All claw lesions were recorded, and a Cow Claw Score (CCS) was calculated for each cow. Locomotion scores (LCS 1–5) were assessed at two-week intervals. Intraruminal sensors for continuous pH measurements were used to determine SARA (pH below 5.8 for more than 330 min in 24 h). The cluster analysis grouped the cows retrospectively into light (≤11%; n = 9), moderate (>11–<30%; n = 7), and severe (>30%; n = 8) SARA groups, based on the percentage of days individual cows experienced SARA. Statistically significant differences were found between SARA groups light and severe in terms of lameness incidence (p = 0.023), but not for LCS and claw lesion prevalence. Further, the analysis of maximum likelihood estimates revealed that for each day experiencing SARA, the likelihood of becoming lame increased by 2.52% (p = 0.0257). A significant increase in white line lesion prevalence was observed between visits 2 and 3 in the severe SARA group. The mean CCS in severe SARA group cows were higher at each visit compared to cows in the other two groups, but without statistical significance. Overall, this is the first study indicating that first-lactation cows fed a similar high-concentrate diet but with a higher severity of SARA tended to have poorer claw health, albeit with only partial statistical evidence.

Elucidating the factors and consequences of the severity of rumen acidosis in first-lactation Holstein cows during transition and early lactation

“…The lacking influence of SARA-type on lying behavior seems explainable by the slow and insidious pathogenesis of feeding-induced laminitis that leads to extended lying durations of dairy cows ( Nocek, 1997 ). Indeed, changes in lying behavior on a short-term perspective are uncommon ( DeVries et al, 2009 ), but we recently reported poor claw health in primiparous dairy cows around 3 mo after the high-grain feeding period ( Kofler et al, 2023 ). Thereby, high SARA severity was associated with higher incidences of lameness and white line lesions.…”

“… Penner et al (2007) used the magnitude of the pH drop to characterize the severity of rumen acidosis, such as ruminal pH between 5.5 and 5.8 indicating mild SARA, between 5.2 and 5.5 indicating moderate SARA, and ruminal pH < 5.2 indicating acute rumen acidosis. Research has suggested that SARA increases the odds of systemic inflammation, laminitis, abomasal displacement, perturbed liver function, and milk fat depression ( Humer et al, 2018 ; Plaizier et al, 2018 ; Kofler et al, 2023 ), and this makes SARA a serious metabolic disorder in dairy cattle. It has also been shown that the risk of SARA is especially high during the first weeks after parturition, when cows are abruptly fed high-grain diets and their rumen is not yet adapted, coupled with the stressors of endocrine and metabolic changes, milking, rehousing, or potential postpartum complications ( Penner et al, 2007 ; Vergara et al, 2014 ; Zebeli et al, 2015 ).…”