Effects of 3 surface types on dairy cattle behavior, preference, and hygiene.

Muddy surfaces have negative effects on the health and welfare of dairy cattle, and if possible, cows will avoid this surface. However, it is unclear whether it is the moisture content or the contamination with manure that is aversive to the cows. This study aimed to assess the use and preference for different wood chip (0.4 m deep) surface types: (1) clean and dry (clean, dry matter content, DM: 44 ± 2.8%), (2) dirty (dirty, contaminated with manure, DM: 40 ± 3.7%), and (3) clean and wet (wet, wetted by water, DM: 23 ± 3.3%). Eighteen nonlactating, pregnant cows were tested individually (mean 24-h temperature: 9.9 ± 4.46°C, mean ± standard deviation for all preceding values). Cows were kept indoors in test pens for 18 h on wood chip without feed and 6 h on pasture to allow for daily feed intake. To ensure cows made informed choices and to measure changes in behavior and hygiene associated with each option, they were first exposed to each surface for 5 d (n = 12 cows per surface type when they were restricted on one surface; i.e., each cow was exposed to 2 treatment surfaces only). Cows on the wet surface spent the least amount of time lying when restricted to one surface for 18 h (wet: 21%, dirty: 57%, clean: 64%) and spent more time lying when on pasture for 6 h (wet: 13%, dirty: 4%, clean: 3%). The total lying times during the 5-d surface exposure were wet: 4.6 ± 1.04 h, dirty: 10.6 ± 0.25 h, and clean: 11.7 ± 0.25 h per 24 h. Cows restricted on the wet surface for 18 h had fewer bouts (no.) of lateral lying (wet: 0.9 ± 1.36, dirty: 6.3 ± 1.36, clean: 8.4 ± 1.38), spent less time lying with their heads supported (wet: 18.9 ± 7.17 min, dirty: 36.7 ± 7.17 min, clean: 39.1 ± 7.26 min), and spent less time with the front legs tucked (wet: 16 ± 4.3%, dirty: 41 ± 4.3%, clean: 50 ± 4.3% of time spent lying, mean ± standard error of the mean for all preceding values), than cows on the other surfaces. Cows on the dirty surface were less clean compared with the other treatment groups (0.6 of a score on a 5-point scale; standard error of the differences of means: 0.11 for both comparisons). They were then given a free choice between 2 known surfaces for 2 consecutive days (n = 6 per pairwise choice). Cows ranked the surfaces as clean > dirty > wet. In summary, there is compelling evidence that wet surfaces impair the welfare of dairy cattle by affecting the quantity and quality of rest. Rebound responses indicate that the motivation to rest is not fulfilled on wet surfaces. Finally, when given a choice, they show clearly that they will avoid wet and dirty surfaces. The combined results indicate that changes in affective state likely underlie these behavioral responses.