Improving Immunity, Health & Well-Being in Production Environments
Researcher looks at animal response variation and how to manage the differences.
Not all creatures respond in the same way to stress. It depends on the particular challenge. It depends on the environment. It depends on the type of animal involved, and it depends on the individual. According to USDA Agricultural Research Service (ARS) scientist Jeff Carroll, response variation exists between and within breeds of cattle, but also among animals of the same herd. Variation between animals can result in different impacts to individual health and productivity.
“We want to know more about the variations, why they occur and how to manage them,” said Carroll, in a presentation to the 4th International Symposium on Beef Cattle Welfare hosted July 16-18 in Ames, Iowa.
Jeff Carroll said this research raises the question of whether cattle producers can go too far with genetic selection for cattle with calm dispositions.
Carroll explained how he and colleagues at the Livestock Issues Research Unit of Lubbock, Texas, have been focused on identifying natural and nutritionally induced variations in the stress and immune response of cattle exposed to a challenge. Studies have revealed variations based on gender (steers vs. heifers), as well as variations directly linked to an animal’s disposition.
“Does temperament influence stress response, innate immune response and metabolic profile? Finding the answers has been a major research effort of our team for the past decade,” said Carroll.
The work has demonstrated that, compared to “calm” cattle, temperamental cattle maintain a higher basal body temperature prior to a challenge, but a lesser temperature change in response to challenge. Studies also showed that temperamental animals are less apt to exhibit typical sickness behavior than are calm cattle. Carroll said the evidence suggests these natural variations are linked to metabolic differences between temperamental cattle and calm cattle.
“Collectively, these data suggest that level of flightiness or arousal can modulate the physiological, behavioral and responses of cattle to a provocative immune challenge that targets activation of the innate immune system,” reported Carroll. “Developing a more precise understanding of the relationship among stress hormones, the immune system and animal temperament to early inflammation may lead to methods of early intervention to minimize the debilitating impacts of illness on growth and productivity.”
Carroll said this research raises the question of whether cattle producers can go too far with genetic selection for cattle with calm dispositions. The up side is that heavy selection pressure may result in cattle that perform very well under conditions that are ideal or nearly so.
“However,” said Carroll, “if they are hit with a significant health challenge, they could crash and burn.”
Editor’s Note: Troy Smith is a freelancer and cattleman from Sargent, Neb. The Angus Journal provides comprehensive coverage of the 4th International Symposium on Beef Cattle Welfare in its October issue.