Behavior of dairy cows in an alternative bedded-pack housing system.

The objectives of this study were to measure lying behavior and social interactions of lactating cows housed in an alternative bedded-pack system, commonly referred to as a compost dairy barn, and to investigate the association between the temperature-humidity index and lying behavior of these cows. The study was conducted in 12 compost dairy barns in Minnesota between late June 2005 and September 2005. Lying, standing, and walking behavior of 147 focal cows was measured by automatic activity monitors. The daily lying time was 9.34 +/- 1.94 h. The number of daily lying bouts was 11.0 +/- 3.2 and the lying bout length was 50.8 +/- 35.6 min. As days in milk increased, the total number of lying bouts increased, corresponding to an increase in total daily lying time. Cows in the compost barns lay down for less time, took more steps, and reduced the length of lying bouts as the temperature-humidity index increased. Social interactions and lying positions of all cows in the bedded-pack area (total of 886 cows in the 12 dairies) were recorded using visual observations during two 4-h periods on 2 separate days. A total of 43.3% of the cows were lying down at any time. All 4 natural lying positions (head back, head up, flat on the side, and head on the ground) were observed in 9 of the bedded packs during the direct visual observation periods. The majority (84.6%) of the cows observed lying down assumed the head-up position. Of all observed lying events, the head-back lying position was assumed 8.8% of the time, the head on the ground 5.4% of the time, and flat on the side 0.8% of the time. Observations of social interactions on the bedded-pack area showed that 0.94 +/- 1.5 incidents of chasing away, 0.94 +/- 1.8 of pushing, 1.4 +/- 1.6 of head butting, and 2.3 +/- 2.9 of allogrooming (social licking) occurred per hour. Observations of lying behavior, social interactions, and natural lying positions indicated that compost dairy barns can be an adequate housing system for dairy cows.