This article reprinted from Animal Net., a news service produced by Guelph University.
Study links SO2 exposure to reduced cattle health and feed efficiency
March 3, 2004
Canada Alberta Beef Industry Development Fund Media Release
Calgary, Alberta: Exposure to sulphur dioxide (SO2), a major air pollutant in Alberta, can adversely affect the health of cattle, and increase winter feed requirements, says a University of Alberta researcher following a three-year investigation.
Cattle exposed to SO2 in a controlled environment showed measurable damage to their lungs and some suppression of the immune system, as well as an increased metabolic rate, particularly during cold weather, says Dr. Bob Christopherson, a specialist in animal physiology.
"The suppression observed in the cattle's immune system has potential to lower the animal's resistance to infection," says Christopherson. "I think we can also safely say that animals exposed to SO2, as a result of their increased metabolic rate, have a higher feed requirement - perhaps 10 percent more feed would be a reasonable estimate."
Poor growth rates, reproductive impairments and respiratory disease in cattle have all been loosely linked to sulphur dioxide emissions, but the University of Alberta study is the first to pinpoint a direct link between exposure to the pollutant and measured effects on the animals' pulmonary and immune systems. While the study showed measured effects at all levels of exposure from 1 to 20 ppm (parts per million), further research is needed to determine the specific impact of these effects on animal health and production.
Sulphur dioxide is a common byproduct released to the atmosphere during activities that process or burn fossil fuels. In rural areas, this has resulted in long-running concerns about the effect that routine emissions from sour gas plants and flare stacks, along with emissions from gas well blowouts or line leaks, may have on the well-being of people and livestock.
"It's a subject that has a lot of interest and a lot of emotion," says Christopherson. "We felt there was a need to answer some of the basic questions about livestock, through controlled exposure studies, to find out at what level we could see an effect.
The health effects on cattle, albeit subtle, were measurable, says Christopherson. "Under ideal conditions these effects may not impact the overall performance of cattle. But if there are other stress factors - if animals were exposed to a particular pathogen at a time when their immune system was compromised - there could be a much greater chance of animals picking up infections."
Christopherson suspects there may be some relationship between cell injury and the observed impacts of damage to the pulmonary system, reduced immune function and increased metabolic rate. However, again more research is needed to confirm this theory.
The research was conducted at the University of Alberta's large animal metabolism centre. Researchers examined the effect of rates of SO2 exposure ranging from 1 part per million (ppm) to 20 ppm on 36 head of cattle between six and 18 months of age. Studies were replicated with different batches of cattle over three years.
Knowing that cold temperature is a stressor for cattle, Christopherson wanted to find out if SO2 exposure was also a stressor, then, if so, determine the combined effect of the two stressors on livestock.
The work confirmed SO2 is a stressor that, when combined with cold temperatures, has potential to affect the health and performance of cattle. Similar research with cattle at 15 to 18 C temperatures - referred to as a thermal-neutral environment - showed exposure to sulphur dioxide did not affect metabolic rate or energy needs.
Christopherson says researchers would need to work with a much larger group of cattle over a longer period to gain a conclusive perspective on animal health impact. "Based on our current limited research, although we saw pulmonary cell damage in this project, we did not see any evidence from clinical biochemistry of severe liver damage or major inflammatory diseases in animals."
CABIDF is a joint $16.4 million fund of Alberta Agriculture, Food and Rural Development and Agriculture and Agri-Food Canada. The Fund is administered by Alberta Beef Producers and has supported more than 50 projects in five major categories identified to benefit the Alberta beef industry.
Study links SO2 exposure to reduced cattle health and feed efficiency
March 3, 2004
Canada Alberta Beef Industry Development Fund Media Release
Calgary, Alberta: Exposure to sulphur dioxide (SO2), a major air pollutant in Alberta, can adversely affect the health of cattle, and increase winter feed requirements, says a University of Alberta researcher following a three-year investigation.
Cattle exposed to SO2 in a controlled environment showed measurable damage to their lungs and some suppression of the immune system, as well as an increased metabolic rate, particularly during cold weather, says Dr. Bob Christopherson, a specialist in animal physiology.
"The suppression observed in the cattle's immune system has potential to lower the animal's resistance to infection," says Christopherson. "I think we can also safely say that animals exposed to SO2, as a result of their increased metabolic rate, have a higher feed requirement - perhaps 10 percent more feed would be a reasonable estimate."
Poor growth rates, reproductive impairments and respiratory disease in cattle have all been loosely linked to sulphur dioxide emissions, but the University of Alberta study is the first to pinpoint a direct link between exposure to the pollutant and measured effects on the animals' pulmonary and immune systems. While the study showed measured effects at all levels of exposure from 1 to 20 ppm (parts per million), further research is needed to determine the specific impact of these effects on animal health and production.
Sulphur dioxide is a common byproduct released to the atmosphere during activities that process or burn fossil fuels. In rural areas, this has resulted in long-running concerns about the effect that routine emissions from sour gas plants and flare stacks, along with emissions from gas well blowouts or line leaks, may have on the well-being of people and livestock.
"It's a subject that has a lot of interest and a lot of emotion," says Christopherson. "We felt there was a need to answer some of the basic questions about livestock, through controlled exposure studies, to find out at what level we could see an effect.
The health effects on cattle, albeit subtle, were measurable, says Christopherson. "Under ideal conditions these effects may not impact the overall performance of cattle. But if there are other stress factors - if animals were exposed to a particular pathogen at a time when their immune system was compromised - there could be a much greater chance of animals picking up infections."
Christopherson suspects there may be some relationship between cell injury and the observed impacts of damage to the pulmonary system, reduced immune function and increased metabolic rate. However, again more research is needed to confirm this theory.
The research was conducted at the University of Alberta's large animal metabolism centre. Researchers examined the effect of rates of SO2 exposure ranging from 1 part per million (ppm) to 20 ppm on 36 head of cattle between six and 18 months of age. Studies were replicated with different batches of cattle over three years.
Knowing that cold temperature is a stressor for cattle, Christopherson wanted to find out if SO2 exposure was also a stressor, then, if so, determine the combined effect of the two stressors on livestock.
The work confirmed SO2 is a stressor that, when combined with cold temperatures, has potential to affect the health and performance of cattle. Similar research with cattle at 15 to 18 C temperatures - referred to as a thermal-neutral environment - showed exposure to sulphur dioxide did not affect metabolic rate or energy needs.
Christopherson says researchers would need to work with a much larger group of cattle over a longer period to gain a conclusive perspective on animal health impact. "Based on our current limited research, although we saw pulmonary cell damage in this project, we did not see any evidence from clinical biochemistry of severe liver damage or major inflammatory diseases in animals."
CABIDF is a joint $16.4 million fund of Alberta Agriculture, Food and Rural Development and Agriculture and Agri-Food Canada. The Fund is administered by Alberta Beef Producers and has supported more than 50 projects in five major categories identified to benefit the Alberta beef industry.