Abstract #W4

# W4
Udder wetness and behavioral responses to showers in the milking parlor.
K. Reuscher*1, R. Salter1, M. Mondaca1, J. Van Os1, 1University of Wisconsin-Madison, Madison, WI.

Sprinklers for cooling dairy cattle are conventionally found in the holding pen or home pens, but these potentially waste water when cows are outside the spray radius. A dairy farm developed a novel system with showers above each milking parlor stall to target spray on the cows’ backs. Our objective was to evaluate how well the spray was targeted with minimal water landing on the udder or head. Eight pens (n = 8) of lactating Holsteins were evaluated during 1 milking/d when cows were sprayed vs. unsprayed (control) on 3 d each. Four focal stalls/parlor side (balanced among the 12 stalls/side across days) were scored for presence of water on the udder with both live observations and digital photographs (standard and infrared) using a standardized scoring system. Thirty focal cows were video recorded during treatment (57–67 s) application. The frequency (bouts/min) of ear flicks, head shakes, and head lowering were measured along with proportion of time for the latter. Linear mixed models were used to evaluate treatment differences within each time period. Before treatment, the percentage of wet udders was the same in the spray and control treatments (0.4 ± 0.3 vs. 0.5 ± 0.3%, mean ± SE; P = 0.08). After treatment, more udders were wet in the spray vs. control treatments (20.6 ± 2.3 vs. 0.5 ± 2.4%; P < 0.001), of which 9.5% (2% of cows) had streams of water reaching the teats or teat cups. Overall, we rarely observed wetness on the udder that could potentially wet the teats. During the spray, cows spent less time with their heads lowered but shook them more frequently in the spray vs. control treatment (1.8 ± 2.5 vs. 11.2 ± 2.6% of time, 0.15 ± 0.04 vs 0.03 ± 0.04 bouts/min, respectively; P < 0.048). However, there was no difference in ear flicks or head lowering between the treatments (ear flicks: 0.11 ± 0.05 vs. 0.07 ± 0.05, head lowering: 0.26 ± 0.07 vs. 0.27 ± 0.07 bouts/min; P > 0.57). Although cows occasionally shook their heads more during spray application, they did not show other behaviors consistent with avoidance of water on the head. On the whole, our findings support that the showers, aimed toward the cows’ backs, rarely sprayed the heads or udders.

Key Words: heat stress, soaker, hygiene