Influence of space availability and weather conditions on shelter use by beef cattle during winter

The objective of this experiment was to evaluate shelter use by beef cattle in relation to space allowance per individual and weather conditions. Nine groups of Angus cattle (n = 35 in total, 3-6/group) were kept on paddocks with a squared shelter (5 × 10 m) with an open long side. In a 3 × 3 crossover design, three experimental treatments were tested based on national recommendations: 1) 100% of the recommended m2/individual (4 m2 per adult), 2) 150% (6 m2 per adult) and 3) 200% (8 m2 per adult). The shelter area was fenced off according to treatment and the number and size of animals in each group. Shelter use was estimated from pictures taken every 15 min with infrared trail cameras placed in all shelters. When the available space per individual was 100% of the recommended space, the shelters were used less compared to when 150% and 200% of the recommended space was available (e.g. percentage of pictures where all animals were inside the shelter (%all_animals): P < 0.001). There was a significant effect of weather conditions on shelter use (e.g. %all_animals; chill factor index: P = 0.03, and precipitation: P = 0.006), i.e. the shelters were used more with decreasing chill factor index and with increased precipitation. In conclusion, beef cattle increased their use of the shelters when the space allowance per individual increased with 50% or 100% compared to the current, national recommendations; e.g. simultaneous use by a whole group doubled with increased space. Furthermore, cold and wet weather increased shelter use.