The amount of shade influences the behavior and physiology of dairy cattle

Using behavioural indicators of thermal discomfort, that is, shade seeking, panting scores (PS) and respiration rate (RR), we evaluated the effect of hot summer conditions and shade, for a herd of adult Holstein dairy cows and a herd of Belgian Blue beef cows kept on pasture in a temperate area (Belgium). During the summer of 2012, both herds were kept on pasture without access to shade (NS). During the summers of 2011 and 2013 each herd was divided into one group with (S) and one without (NS) access to shade. Shade was provided by young trees with shade cloth (80% reduction in solar radiation) hung between them. For S cows, we investigated how shade use was related to hot conditions as quantified by six climatic indices. The heat load index (HLI), which incorporates air temperature and humidity, solar radiation and wind speed, was the best predictor of the six indices tested. In 2011, there was a relatively high threshold for use of shade. When HLI = 90, shade use probability reached 17% for dairy cows and 27% for beef cows. In 2013, however, at HLI = 90, shade use probability reached 48% for dairy cows and 41% for beef cows. For animals from the NS treatment we determined the effect of hot summer conditions on RR and PS (with 0 = no panting and 4.5 = extreme panting). In both types of cattle, an increase in black globe temperature was the best predictor for increasing RR and PS. Furthermore, we determined how the effect of hot summer conditions on RR and PS was affected by the use of shade. Under hot conditions (black globe temperature ⩾ 30°C), >50% of the animals under shade retained normal PS and RR (PS < 1 and RR < 90 breaths per minute), whereas normal RR and PS were significantly less prevalent for animals outside shade. Our findings suggest that, even in temperate summers, heat can induce thermal discomfort in cattle, as evidenced by increases in shade use, RR and PS, and that shade increases thermal comfort.

Section: Discussionsupporting

confidence: 92%

Section: Rr and Ps As Indicators Of Thermal Discomfortmentioning

confidence: 99%

Effect of summer conditions and shade on behavioural indicators of thermal discomfort in Holstein dairy and Belgian Blue beef cattle on pasture

laer¹,

Moons

Ampe³

et al. 2015

“…Increased aggression was also noticed by Schütz et al (2010). In the present study, cows from different treatments had visual contact with each other, so cows without access to shade might have enhanced their frustration by seeing the other cows freely accessing shade.…”

Section: Discussionmentioning

confidence: 50%

“…The absence of an effect of access to shade on total time spent standing and lying was unexpected as some studies reported increase in time spent standing to increase heat dissipation by convection (Anderson et al, 2013) while others (Tucker et al, 2008;Schütz et al, 2010) have reported that increased standing time is partly attributed to insufficient cow shade. This was not the case in the present study as cows had more than 10 m 2 each of available shade.…”

Section: Discussionmentioning

confidence: 99%

Access to shade changes behavioral and physiological attributes of dairy cows during the hot season in the subtropics

Vizzotto

Fischer

Neto

et al. 2015

The effect of shade on behavior and physiological attributes of grazing cows in a high altitude subtropical zone is not well established. This work aimed to investigate how social and ingestive behaviors, as well as physiological and other attributes of dairy cows such as milk production, change in a subtropical environment during the hot season either with or without free access to shade. Fourteen lactating cows were kept on pasture either with no shade or with free access to shade for 5 days and their behavior was recorded with instantaneous scan sampled every 10 min, from sunrise, 0530 h (Greenwich mean time, GMT − 0200 h) to sunset, 2100 h (GMT − 0200 h). Behavior traits included (1) time spent in activities such as grazing, ruminating, resting, lying, standing, walking, seeking shade and staying in the proximity to the water trough and (2) number of events such as water ingestion, aggressive interactions, as well as competition for shade and water. Physiological attributes such as heart and respiratory rates, rectal temperature, number of rumen movements, panting score, as well as milk yield, were evaluated. Time spent in behavioral activities, number of behavioral events and physiological attributes varied between groups (with and without access to shade). Cows with no shade showed increased respiratory and heart rates and panting score at 1300 h, higher values for time of permanence near the water trough, number of competition and aggression events for shade. On the other hand, they showed lower values for time spent resting while lying, ruminating while standing, seeking shade. Access to shade did not change time spent lying, standing, walking with the head up, ruminating while lying, resting while standing, as well as milk yield and number of ruminal movements. Significant interactions between access to shade and days of measurements were detected for time spent walking, ruminating, grazing, resting, number of water ingestion events, competition events near the water trough and for shade, as well as for rectal temperature and panting score measured at 1700 h. In the high altitude subtropical region, access to shade minimizes negative heat stress effects on behavior and physiological aspects of dairy cows.

“…A shade structure is one way of reducing the impact of heat stress (Armstrong, 1994;Muller et al, 1994a). Research has addressed the issue of type of shade mainly on confined cattle (Ittner and Kelly, 1951;Eigenberg et al, 2009) and on high-producing dairy cattle (Valtorta et al, 1997;Gaughan et al, 1998;Tucker et al, 2008;Schütz et al, 2009Schütz et al, , 2010. However, little is known about the effect of the type of shade on grazing beef cattle in a low-to-medium plane of nutrition.…”

Section: Introductionmentioning

confidence: 99%

The effect of type of shade on physiology, behaviour and performance of grazing steers

Rovira

2014

Research has addressed the issue of type of shade mainly on feedlots and high-producing dairy farms, but more studies are needed on the impact of shade on grazing beef cattle in a low-to-medium plane of nutrition. A 63-day grazing study using 24 British steers (268 ± 4 kg) was undertaken in Uruguay (33°14'S, 54°15'W) to determine the effect of type of artificial shade on tympanic temperature (TT), behaviour and performance during summer. Cattle were allocated to six paddocks with an area of 2.5 ha each (four steers/paddock) continuously grazed. Treatments (two paddocks/treatment) were unshaded (US) and shaded with either 35% (35S) or 80% (80S) blockage of solar radiation. TT was recorded during 12 days placing an automatic device near the tympanic membrane inside the animal's ear. Animal behaviours were measured by live observations of animals every 15 min from 1100 to 1600 h six times during the experimental period. According to the temperature-humidity index (THI), cattle was in the 'normal' category (THI < 70, absence of heat stress) during 50% of the time, the rest being exposed to some degree of heat stress including 15% of the time with environmental conditions. Black globe temperature and surface soil temperature decreased as solar protection increased under the shade structure. Steers spent more time under the 80S structure than under the 35S between 1100 and 1600 h (83% and 49% of the time, respectively). Average 24-h TT did not differ among treatments (mean ± s.e. 38.79 ± 0.04ºC). Minimum TT was registered at 0700 h for all treatments (37.92 ± 0.08ºC), whereas maximum TT was reached at 1700 h for both control group (39.73 ± 0.18ºC) and 35% shade (39.48 ± 0.12ºC) and at 1900 h for 80% shade (39.57 ± 0.15ºC). Neither the provision nor the type of shade affected animal performance (0.622 ± 0.060 kg/a per day), indicating the ability of cattle to acclimate and/or compensate for eventually short-term severe heat stress events. The results of this experiment suggest that the provision of shade with either 35% or 80% of blockage of solar radiation is recommended for the improvement of cattle well-being (expressed through changes in behaviour) without significantly affecting animal performance and TT. However, the overall results of the 63 days of the study can mask or dilute punctual effects of short heat stress events on cattle. More powerful experimental designs are required to address this issue in temperate regions.Keywords: cattle, heat stress, shade, behaviour, tympanic temperature ImplicationsMinimizing the risk of heat stress of cattle during summer is important from both production and animal welfare standpoints. The provision of artificial shade with 35% or 80% blockage of solar radiation increased the time cattle spent under the shade during the hottest hours, although shade did not affect overall animal performance and tympanic temperature. Thus, in extensive beef cattle operations in temperate regions, the main effect of shade would be in animal comfort rather than in productivity or body tempera...