Associate Professor Anders Herlin & Associate Professor Christian Swensson[1], dept. of Agricultural Buildings, Faculty of Landscape, Horticulture and Agriculture, Swedish University of Agricultural Science, SE-23053 Alnarp, Sweden

GIS AND GPS ARE TOOLS BOTH FOR PRACTICAL FARMING AND AGRICULTURAL RESEARCH

C. Swensson, A. Herlin

GIS/GPS technology have changed agricultural research and also practical farming concerning range cattle on large areas. Questions as where are the position of the cattle in the landscape can be answered by using automatic GPS technology. In cooperation with GIS information regarding landscape type it is possible to get a lot of information in a very rapid way.

Cowboy’s virtuell rope

When cattle are grazing large pastures, the farmer wants to be able to rapidly find the animals to count them and check their health status. If some of the animals have GPS-transmitters it is possible to find the animals both rapidly and efficiently. The management of the animals is improved and furthermore, by using a mobile and GPS-transmitter it is possible for the modern cowboys to find the animals.

GIS and GPS in agricultural research

Thermal stress concerns for cattle on winter range an animal welfare issue

All farm animals are homeothermic, showing a relatively constant long-term body temperature under the most varying conditions despite large variation of internal heat production due to metabolism or variation in the thermal environment. Mount (1973) explained the thermal regulation depending on ambient temperature where the thermoneutral zone is a very important concept. The definition of the thermoneutral zone is the range of environmental temperatures within which the metabolic rate is constant minimum and independent of temperature. The lower and upper critical temperatures define the limits of the thermoneutral zone. At environmental temperatures below the lower critical temperature, an increase in the metabolic heat production, by cold thermogenesis by the animal is necessary in order to maintain it’s body temperature. The animal will in the short term adapt to this situation by consuming more energy and/or behave in ways that reduces the heat loss. Physiological changes occur in the long term to increase heat production. The total heat loss from the animal is divided into sensible (energy lost by mainly radiation) and latent (energy lost by evaporation) heat loss. Below the lower critical temperature the latent heat loss is constant at its minimum and the sensible heat loss increase with decreasing ambient temperature. Bruce (1986) and Ehrlemark & Sällvik (1996) have presented theoretical models for heat production and lower critical temperature for cattle.

Wind chill is the apparent temperature felt on exposed skin due to the combination of air temperature and wind speed and potential cause for sensible heat loss. However, Keren & Olson (2006) have shown that cattle position their body in the same direction as the wind and therefore maintains the insulating properties of the coat and therefore minimizes the heat loss and previous estimates of “chill-factor” is too high.

Farm animal energetic requirements and metabolism under cold conditions are often studied in controlled environments or metabolic chambers, or by using heat sources covered with a pelt (Webster, 1971; Bruce, 1977; Bruce 1979; Bruce, 1984; Jones & Bruce, 1985; MacCormack & Bruce, 1991; Okamoto & Sone, 1989; Wejfeldt, 1991; Redbo et al., 1996).

Adult cattle are generally extremely cold-hardy because of their large body size, well-developed insulation and relatively high rates of metabolic heat production (Young, 1985). Cattle also respond differently while grazing during winter (Yousef, 1989). Cattle and wildlife conserve energy by lowering metabolic rate or resting heat production (Cuyler & Oritsland, 1993; Bergen et al., 2001; Han et al., 2003), seeking shelter (Redbo et al., 2001), altering activity patterns (Schaefer & Messier, 1996; Olson & Wallander, 2002) and orienting to the sun and wind (Gonyou & Stricklin, 1981).

The extrapolation of energetic requirements from controlled studies to natural environments may lead to conclusions that cattle are more exposed to cold stress than is the actual case. Previous calculations did not account for the irradiative environment and behavioural adaptations by the animals and thus overestimated metabolic requirements of cattle acclimatized to grazing winter range (Keren & Olson, 2006).

Animal welfare is composed of several traits, maintaining homeostasis by handling thermal stress, achievement of adequate resting, energy balance within a range, maintain a good health, social interactions and maintain coat condition. Resting and coupled behaviours (lying down and getting up) indoors have provided useful parameters to evaluate equipment and environments conditions (e.g. Herlin, 1997). But, these have yet to be proven outdoors.

Interaction of landscape and animals

Landscape elements like trees, shrubs, heights, and the spatial arrangement of these will together with variation in the topography influence the local climate like wind speed and temperature. This will protect soils; improve productivity of the land and sustainability. A systematic planting of 10 % of the land in a net of shelterbelts/timberbelts/clusters would achieve a 50% wind speed reduction (Bird, et al., 1992; Bird, 1998). In studies on the interaction between e.g. trees and cattle have pointed out the importance of the trees for the animal to seek shelter from the sun in the summer but the trees were less important in winter (McIlvai, & Shoop, 1971; Blackshaw & Blackshaw, 1994).

The studies on the effects of shelterbelts, giving wind break for feedlot cattle in Nebraska has been inconclusive (Mader et al., 1997). The performance of yearling animals was not improved during winter by providing a tree windbreak compared to those without and also, providing wind protection during summer resulted in decreased cattle gains during summer. But in a follow up study, the performance of heavy steers was severely impaired when no protection was provided in the winter. The studies indicate that possible benefits of feeding cattle in sheltered areas in winter can be offset by lower performance in summer. But cattle in cattle approaching slaughter, wind protection in winter will always be beneficial as fat deposition is higher in animals with no protection.

Olson & Wallander (2002) found that activity patterns of windbreak and non-windbreak cattle differed only slightly, indicating they used similar behaviours to minimize energy expended and to maximize energy gain. Time spent grazing was inconsistent between two winter trials, possibly reflecting large differences in body condition when they entered each winter. For individual groups, time spent grazing and standing varied widely on a day-to-day basis, reflecting either an immediate response to that day's weather, or possibly a compensatory response to the previous day's weather, especially following cold, windy days. Wind velocity had minimal effect on grazing time, presumably because high wind velocities were associated with relatively warm days, or the animals were in sufficient condition to tolerate high wind velocities. Instead of minimizing energy expended by lying down during extreme cold, cattle spent more time standing, which maximizes heat from solar radiation.

In a study by Harris et al. (2002) cattle responded to climate in winter by grazing south slopes on cold but sunny days, during coldest winter days cattle moved to higher but warmer but still sheltered areas and on rainy winter days they moved to lower sheltered areas.

Conclusions

By using GIS/GPS technology, it is possible to investigate questions and problems which by old research methods earlier were very laborious and time consuming to register and analyse. Referring to Swedish conditions maybe the most interesting problem to investigate by using GIS/GPS technology is how to manage cattle on winter range, especially how cattle cope with the landscape. Cattle have the answer to the question, which type of landscape is the best during wintertime.

References

Anderson, D.M.2000. The cyber cow whisperer and his virtual fence. Agricultural Research November

Bergen, R. D., A. D. Kennedy, and R. J. Christopherson. 2001. Effects of intermittent cold exposure varying in intensity on core body temperature and resting heat production of beef cattle. Can. J. Anim. Sci. 81:459–465.

Bird, P.R., Bicknell, D., Bulman, P.A, Burke, S.J.A., Leys, J.F., Parker, J.N., Van DerSommen, F.J. & Voller, P. 1992 The role of shelter in Australia for protecting soils, plants and livestock Agroforestry Systems 20, p. 59 – 86.

Bird, P.R. 1998 Tree windbreaks and shelter benefits to pasture in temperate grazing systems. Agroforestry Systems 41 p. 35 - 54

Blackshaw, J.K. & Blackshaw, A.W. 1994. Heat stress in cattle and the effect of shade on production and behaviour: a review Australian Journal of Experimental Agriculture 34, p. 285 - 295

Bruce, J.M. 1984. Climate and the value of shelter for suckler cows and calves. Farm Building Progress, nr. 78, pp 21-25

Cuyler, L. C., and N. A. Oritsland. 1993. Metabolic strategies for winter survival by Svalbard reindeer. Can. J. Zool. 71:1787– 1792.

Ganskopp D. 2001 Manipulating cattle distribution with salt and water in large arid-land pastures: a GPS/GIS assessment. Appl Anim Behav Sci. 73, p. 251-262.

Ganskopp, D. 2002. Tracking Movement of Cattle With Satellites issue of Agricultural Research magazine. Vol. 50, No. 8 August. http://www.ars.usda.gov/is/AR/archive/aug02/cattle0802.pdf

Gonyou, H. W., and W. R. Stricklin. 1981. Orientation of feedlot bulls with respect to the sun during periods of high solar-radiation in winter. Can. J. Anim. Sci. 61:809–816.

Han, X. T., A. Y. Xie, X. C. Bi, S. J. Liu, and L. H. Hu. 2003. Effects of altitude, ambient temperature and solar radiation on fasting heat production in Yellow cattle (Bos taurus). Br. J. Nutr. 89:399–407.

Harris, N.R., Johnson, D.E., George, M.R. &. McDougald, N.K. 2002. The Effect of Topography, Vegetation, and Weather on Cattle Distribution at the San Joaquin Experimental Range, California. USDA Forest Service Gen. Tech. Rep. PSW-GTR-184.

Jones, C.G. & Bruce, J.M. 1985. Shelter studies using thermal models of cattle. Progress in Biometeorology, 2:83-98

Keren E.N. & Olson B.E. 2006. Thermal balance of cattle grazing winter range: Model application. J. Anim. Sci. 84, s.1238–1247

Mader T.L., Dahlquist, J.M. & Gaughan, J.B. 1997. Wind protection effects and airflow patterns in outside feedlots. J. Anim. Sci. 75, p. 26-36

McIlvain, E.H. & Shoop, M.C. 1971. Shade for Improving Cattle Gains and Rangeland Use. Journal of Range Management 24, p. 181-184

MacCormack, J.A.D. & Bruce, J.M. 1991. The horse in winter – shelter and feeding. Farm Building Progress, nr. 105, pp 10-13

Olson, B. E. & Wallander. R. T. 2002. Influence of winter and shelter on activity patterns of beef cows. Can. J. Anim. Sci. 82:491–501.

Redbo, I., A. Ehrlemark, and P. Redbo-Torstensson. 2001. Behavioural responses to climatic demands of dairy heifers housed outdoors. Can. J. Anim. Sci. 81:9–15.

Schaefer, J. A., and F. Messier. 1996. Winter activity of muskoxen in relation to foraging conditions. Ecoscience 3:147–153.

[1]