Behavioural responses to climatic demands of dairy heifers housed outdoors

Abstract

Redbo, I., Ehrlemark, A. and Redbo-Torstensson, P. 2001. Behavioural responses to climatic demands of dairy heifers housed outdoors. Can. J. Anim. Sci. 81: 9-15. The aim of the present study was to investigate the behavioural responses to different climatic demands of growing dairy heifers, during winter at a latitude of 60°N. Two groups (n = 11, 12) of yearling dairy heifers were housed in two similar 3-ha enclosures, characterised by deciduous forest, ley and pasture. Each enclosure also contained a lying area, a heated water source and a feed bunk from which the heifers had free access to grass silage. The behaviour and location of each heifer were recorded by instant interval observations every 5 min between 0600 h and 2000 h during 23 observation days spread over the entire winter period. Outdoor temperature, wind speed and solar radiation were measured continuously. The climatic energy demand (CED, W m -2 ) was measured with a heated animal model. The climate had significant effects on all the main activities and on the location of the heifers. Higher CED values corresponded to a greater number of observations of heifers in the lying area, and a greater incidence of lying and of ruminating, but to a decreased incidence of eating and grazing. Increased migration to the forested areas instead of to open areas reflected increasing CED values. The results from the present study show that dairy heifers adapt their behavioural activity and choice of location to the climatic conditions, to reduce energy expenditure. Thus, dairy heifers can be sustained in a cold climate if they are provided with wind breaks and dry lying places.

Summaries

“…Dairy heifers adapt well to cold outdoor conditions if provided with shelter and a dry lying (Redbo et al, 2001), and out-wintering mature cattle on forage crops can achieve similar levels of animal performance to housing (Keogh et al, 2009). Out-wintering systems in Great Britain are farmer-led innovations (Barnes et al, 2013), therefore a survey of these farmers was conducted to assess current practice with a view to informing dairy farmers who are considering employing this system of heifer rearing.…”

Effects of outdoor winter housing and feeding level on performance and blood metabolites of suckler cows fed whole-crop barley silage

“…In most cases, cold conditions or absence of shelters have affected animal performance negatively (e.g. Birkelo et al, 1991;Delfino and Mathison, 1991;Kubisch et al, 1991) or have changed animal behaviour (Redbo et al, 2001). On the contrary, McCarrick and Drennan (1972a,b) and Redbo et al (1996) reported no negative effects on animal health and live weight gain.…”

The effect of dry cow winter management system on feed intake, performance and estimated energy demand

“…Exposure to adverse environmental conditions induces a variety of behavioural and physiological responses associated with impaired performance, and thus animal housing aims to eliminate or moderate negative effects of the environment (National Research Council (NRC), 1981). Cows exposed to harsh weather spend less time feeding (Redbo et al, 2001;Tucker et al, 2007 ) and more time standing (Kiernan, 2004;Tucker et al, 2007) compared with sheltered cows. Cold conditions and excessive standing causes an increase in the secretion of cortisol, particularly in thin cows (Fisher et al, 2002;Tucker et al, 2007), which is in turn associated with reduced growth (Purchas et al, 1980).…”