Abstract #M41

# M41
The effects of comfortable or stressful housing environments on short-term behavior, milk quality, and milk production following group transition for Holstein dairy cattle.
Anna Bradtmueller*1, Matthew Borchers1, Jeffrey Bewley2, 1University of Kentucky, Lexington, KY, 2CowFocused Housing, Bardstown, KY.

The objective of this study was to determine how behavior, milk quality, and milk production of cows differs on a short-term basis following movement into a high comfort, low stress (HC) or a low comfort, high stress (LC) environment. The study was conducted at the University of Kentucky Coldstream Research Dairy from July to September 2017. Lactating Holstein dairy cows (n = 30) were balanced for DIM (>100 DIM) and parity. Cows were assigned to either HC or LC housing for the first 28 d of the study. At the midpoint, cattle were crossed-over to the alternate housing for the remaining 28 d. Quarter-level SCC and culture samples were collected every 24 h following movement into the new environments. Quarters with no clinical symptoms, a SCC ≥200,000 cells/mL, and a positive culture were considered subclinically infected. Daily milk yield, fat, protein, and solids were recorded by the AfiLab System (Afimilk, Kibbutz Afikim, Israel). AfiTag II leg-bands (Afimilk) monitored lying time and CowManager ear tags (Agis, Harmelen, the Netherlands) monitored activity, rumination, and feeding behaviors. Statistical analyses were performed using SAS 9.3 (Cary, NC). Univariate models treating activity, lying time, composite SCS, rumination, feeding behavior, and energy-corrected milk (ECM) as dependent variables were developed. Baseline values for each predicted variable (3-d moving average before transition), day after transition (d 1 to 7), and housing type were treated as independent variables. Univariate models determined independent variables for multivariate models. Cow within housing type served as a repeated effect. Housing significantly affected activity (HC = 224.0 and LC = 260.8 min; P < 0.01), lying time (HC = 684.3 and LC = 516.8 min; P < 0.01) composite SCS (HC = 1.3 and LC = 1.7; P = 0.02), rumination (HC = 571.9 and LC = 498.7 min; P < 0.01), feeding behavior (HC = 106.4 and LC = 90.1 min; P < 0.01), and ECM (HC = 33.2 and LC = 31.8 kg; P < 0.01). Transitions to new environments had a greater impact in the LC environment than the HC environment, indicating producers should place greater emphasis on cow comfort at these times.

Key Words: somatic cell count, subclinical infection, health