Effects of seasonal and climate variations on calves’ thermal comfort and behaviour

Abstract

The aim of this study was to measure the effect of season and climate variations on thermal comfort and behaviour of 6-month-old dairy calves housed in a semi-opened shelter to develop animal-based indicators for assessing animal thermal comfort. The ultimate purpose was to further exploit the use of those indicators to prevent thermal stress by providing appropriate care to the animals. Measurements were taken for winter and summer seasons. Results showed that season significantly influenced (P ≤ 0.01) the lying down behaviour of calves by reducing the time spent lying, from 679.9 min in winter to 554.1 min in summer. Moreover, season had a significant influence (P ≤ 0.01) on feeding behaviour. In detail, the total length of feeding periods was shorter in winter, 442.1 min in comparison to 543.5 min in summer. Time spent drinking increased significantly (P ≤ 0.001), from 11.9 min in winter to 26.9 min in summer. Furthermore, season had a significant influence (P ≤ 0.001) on self grooming behaviour which was 5.5 times longer in duration in winter than in summer (1,336 s vs 244 s). It was concluded that calves' thermal comfort is affected by seasonal and climate variations and that this can be assessed by measuring behaviour with animal-based indicators, such as lying down, resting, standing up, feeding, rumination, drinking and self grooming. The indicators developed may be a useful tool to prevent animal thermal stress by providing appropriate housing and handling to calves under seasonal and climate challenge.

In utero exposure to heat stress during late gestation has prolonged effects on the activity patterns and growth of dairy calves

“…Interestingly, standing and lying in cows is influenced by environmental factors, with lying time decreasing under conditions of heat stress (Cook et al, 2007), likely in an attempt by the cow to facilitate evaporative cooling. Similarly, calves spend more time lying in winter than in summer (Tripon et al, 2014). It could be speculated that differences in perception of thermal comfort may have influenced some activity patterns in the present study, considering that calves born to HT cows spent less time standing and also tended to have higher rectal temperatures.…”

“…Understanding behavior is also a valuable tool when assessing animal welfare, and activity patterns are influenced by a range of factors, such as bedding material and comfort (Sutherland et al, 2014), and health (Proudfoot et al, 2014). Activity is also influenced by temperature: both calves and cows spend less time lying down in hot summer temperatures (Overton et al, 2002;Tripon et al, 2014). However, studies exploring the effect of in utero heat stress on the activity of dairy calves are lacking.…”

A Cross-regional Comparison of Growth in Japanese Black Calves

“…The monthly mean THI of Northern Japan was significantly lower than that of Southern Japan T (°C) -1.3 ± 0.5 -0.5 ± 0.7 3.3 ± 0.6 8.9 ± 0.5 14.4 ± 0.7 18.0 ± 0.2 22.3 ± 0.4 24.1 ± 0.3 19.9 ± 0.4 13.1 ± 0.5 7.1 ± 0.8 1.8 ± 0.6 RH (%) 80.5 ± 1.2 76.3 ± 1.9 71.0 ± 0.7 63.8 ± 3.0 70.5 ± 2.5 79.8 ± 2.1 80.3 ± 1.7 78.0 ± 1.2 75.8 ± 1.5 72.0 ± 1.6 75.0 ± 1.0 78.8 ± 1.9 THI 32.8 ± 0.8 34.6 ± 1.3 40.1 ± 1.0 49.1 ± 1.0 57.1 ± 0.9 63.4 ± 0.4 70.8 ± 0.4 73.6 ± 0.7 67.6 ± 1.6 56.6 ± 0.9 47.2 ± 0.7 36.8 ± 1.6 Southern Japan T (°C) 6.3 ± 0.3 4.6 ± 0.3 11.7 ± 0.4 16.1 ± 0.7 20.1 ± 0.3 22.4 ± 0.4 26.7 ± 0.6 27.3 ± 0.4 24.2 ± 0.6 19.9 ± 0.7 14.1 ± 0.9 8.2 ± 1.0 RH (%) 72.5 ± 2.4 71.8 ± 1.8 71.3 ± 1.3 73.8 ± 3.7 73.0 ± 2.7 86.0 ± 2.1 81.0 ± 2.1 79.8 ± 2.5 80.3 ± 2.5 76.3 ± 2.2 80.0 ± 1.5 76.0 ± 0.7 THI 45.5 ± 0.4 47.6 ± 0.4 54.1 ± 0.6 60.3 ± 1.0 66.4 ± 0.4 71.0 ± 0.5 77.8 ± 0.6 78.7 ± 0.4 73.0 ± 0.5 65.6 ± 0.7 57.0 ± 1.4 47.8 ± 1.3 T: temperature; RH: relative humidity; THI: temperature-humidity index (Okada et al 1984). The capacity of cows to compensate for climatic effects may vary with the housing system (Tripon et al 2014). Thus, we assumed that the barn and management styles adapted to the environment of each region modify the impact of the external environments.…”

A method of outdoor housing dairy calves in pairs using individual calf hutches

“…The differences between the weeks of the winter trial in lying time, bout frequency, and duration are difficult to explain. Steers have been reported to lie down more at lower temperatures (Redbo et al, 1996;Tripon et al, 2014), whereas calves have laid the same amount across 4 different ambient temperatures in controlled indoor environments (5, 9, 13, and 18°C;Schrama et al, 1993). The average minimum temperature during the outdoor winter trial for Tripon et al (2014) was 3°C.…”

“…Steers have been reported to lie down more at lower temperatures (Redbo et al, 1996;Tripon et al, 2014), whereas calves have laid the same amount across 4 different ambient temperatures in controlled indoor environments (5, 9, 13, and 18°C;Schrama et al, 1993). The average minimum temperature during the outdoor winter trial for Tripon et al (2014) was 3°C. However, the ambient temperatures experienced by calves in our winter trial were lower than in previous studies, and calves were older than reported by Schrama et al (1993).…”