Investigating inflammation management of dairy cows during the calving transition period
Creators: Engelking, Lauren E.
Publisher: name: University of Alberta Library
Year: 2023

<p>The calving transition is a challenging period for dairy cows characterized by negative energy balance, metabolic dysfunction, and inflammation, each of which may compromise milk production. Despite extensive research in this area, much is still unknown on how to best manage this period. The overall objective of this thesis research was to investigate inflammation management in dairy cows during the calving transition including 1) evaluation of nutritional (Chapter 2, 3, 5) and anti-inflammatory treatment (Chapter 2 and 3), 2) assessment of variation in transition cow physiology and metabolism, and the relationship with inflammation (Chapter 4 and 5), and 3) validation of a marker specific to gastrointestinal inflammation (Chapter 6). Chapter 2 and 3 assessed the effects of dietary butyrate supplementation and oral non-steroidal anti-inflammatory drug (NSAID) administration, in a 2 × 2 factorial arrangement of treatments, on serum inflammatory markers, productivity, uterine inflammation, and interval to first ovulation. Cows were randomly assigned to dietary butyrate supplementation (n = 42), or a control diet (n = 41) from 28 d before calving, until 21 days in milk (DIM). In the same study, cows were also assigned to receive oral NSAID (n = 42), or an oral placebo (n = 41), at 12-24 h after calving. Dietary butyrate supplementation increased plasma fatty acid concentration, and tended to increase serum inflammatory marker concentration, haptoglobin (Hp), 4 d before calving. Cows receiving NSAID tended to have delayed ovulation, compared to cows that did not receive NSAID. Overall, dietary butyrate supplementation and oral NSAID administration were ineffective in improving milk yield or reproductive performance, or reducing systemic or uterine inflammation in dairy cows.Chapter 5 assessed the effects of offering free choice hay for the first 5 DIM on productivity, serum inflammatory markers, gut permeability, and colon gene expression in fresh dairy cows. Cows were randomly assigned to receive free choice hay, separate from total mixed ration (n = 20), or only total mixed ration (n = 12). Cows offered free choice hay tended to have lower concentration of serum Hp at 3 DIM. Amongst cows offered free choice hay, cows that consumed more hay had a smaller increase in serum amyloid A, and tended to have a smaller increase in Hp concentration from calving to 3 DIM. However, milk yield was not increased in cows offered free choice hay, perhaps due to reduced total dry matter intake (DMI).Chapter 4 and 5 assessed factors associated with inter-cow variation in intake, metabolism, and physiology. Cows assigned to free choice hay, described in Chapter 5, were examined in Chapter 4 to assess factors associated with variable free choice hay intake; cows with lower pre-calving DMI, and higher concentration of plasma β-hydroxybutyrate and serum Hp at calving consumed more free choice hay. Chapter 5 evaluated factors associated with variation in gut permeability; gut permeability tended to be negatively correlated with pre-calving DMI (P = 0.07, r = -0.36), and tended to be positively correlated with serum Hp concentration at 3 DIM (P = 0.07, r = 0.35), indicating postpartum greater gut permeability is related to lower pre-calving DMI and higher serum Hp concentration after calving.Chapter 6 investigated fecal calprotectin as a marker of gastrointestinal tract inflammation. Preliminary data obtained using a commercial calprotectin analysis kit showed little variation amongst samples, regardless of the cow the sample was collected from, or the time-point at which the sample was collected (prepartum vs. postpartum). Four additional commercial calprotectin analysis kits were then assessed; results obtained were infeasible or highly variable amongst kits, thus it is unknown which kit, if any, provides accurate calprotectin concentrations. In conclusion, dietary butyrate supplementation and oral non-steroidal anti-inflammatory drug administration are not recommended for transition dairy cows. However, offering free choice hay may be an effective strategy to accommodate inter-cow variation in periparturient factors; cows with lower intake before calving, and cows with greater fat mobilization and serum inflammatory marker concentration at calving may voluntarily increase free choice hay intake, and free choice hay intake may reduce serum inflammatory marker concentration in cows. Finally, this research highlights the remaining need for validation of a marker specific to gastrointestinal inflammation in dairy cows which would vastly improve our ability to manage such inflammation.</p>