Abstract #36

# 36
Significance of cow cooling practices and bulk tank milk quality parameters in southeastern United States dairy farms.
Z. Mason*1, D. T. Nolan2, P. D. Krawczel3, G. M. Pighetti3, C. S. Petersson-Wolfe4, A. E. Stone1,2, J. M. Bewley2, S. H. Ward5, 1Mississippi State University, Starkville, MS, 2University of Kentucky, Lexington, KY, 3University of Tennessee, Knoxville, TN, 4Virginia Polytechnic Institute and State University, Blacksburg, VA, 5North Carolina State University, Raleigh, NC.

The objective of this investigation was to identify heat abatement management practices (HAMP) that significantly influence mean annual bulk tank somatic cell count (SCC) and score (SCS) and standard plate count (SPC) in dairy farms participating in the Southeast Quality Milk Initiative project (USDA-NIFA-AFRI grant no. 2013–68004–20424). Producers from Mississippi, Kentucky, Tennessee and Virginia (n = 7, 96, 84, and 96; respectively) completed On-farm surveys from July 8, 2014 to August 3, 2015. Mean annual bulk tank SCC and SPC were calculated from 2014 Federal Order data. A total of 283 surveys were procured for analysis. The GLM procedure of SAS (Version 9.4 SAS Institute, Inc., Cary, NC) was used to perform one-way ANOVA to determine significance of HAMP. Use of fans and evaporative cooling (EC) significantly influenced SCC (P = 0.001 and P = 0.015), SCS (P = 0.008 and P = 0.046), and SPC (P = 0.041 and P < 0.0001, respectively). Method used to decide when to activate HAMP did not influence parameters. When ambient temperature was used as the decision tool, threshold temperature when fans were activated influenced SCC (P = 0.044), but not SCS (P = 0.053) nor SPC (P = 0.241). Threshold temperature when EC was activated significantly influenced SCC (P = 0.008) and SCS (P = 0.046), but not SPC (P = 0.732). Coefficients of correlation ranged from 0.007- 0.109, 0.009- 0.089 and 0.002- 0.136 for SCC, SCS and SPC respectively. This suggests HAMP may not be able to recover milk quality parameters as well as might be hoped. Identifying management practices correlated to improved milk quality helps producers and consultants in meeting regional, national and international demand for high quality dairy products.

Key Words: bulk tank somatic cell count, somatic cell score, standard plate count