|dc.description.abstract||. Feeding large numbers of cattle in feedlots is a challenge in many respects including nutrition, health, transport, and slaughter. A field of growing importance is animal wellbeing and environmental aspects. The two main challenges for environmental management in the feedlot industry are to lower climatic stress, and to improve air quality. This dissertation covers the areas of a) ethological sampling methods for feedlot cattle, b) environmental management practices that lower heat stress in feedlot cattle, and c) behavioral management practices of cattle that control dust in feedlots.
In the first study, 64 crossbred heifers were used to determine and validate accurate, precise, and efficient behavioral sampling techniques. When focal animal sampling, scan sampling, and time sampling were compared to continuous sampling, it was found that scan sampling in 10-min intervals as well as focal animal sampling were accurate and precise methods to quantify behavior of feedlot cattle.
In the second study, a total of 112 crossbred heifers were used in the Texas Tech University feedlot in the summers of 1998 and 1999. The objective was to assess the impact of heat stress and its relief by shade and (or) water misting on behavior, physiology, performance, and carcass traits. Cattle without shade had a physiological and behavioral stress response to heat that negatively affected production. Providing shade significantly decreased heat stress and lowered the negative effects of heat on performance, whereas misting with water was largely ineffective.
The objective of the third study, was to decrease the aerial dust concentration in a commercial feedlot by modifying dust-generating behaviors of feedlot cattle. It was hypothesized that through changes in feeding management practices, cattle activity patterns that result in high quantities of dust might be redirected towards feeding and ruminating behaviors that generate significantly less dust. It was found that changing the feeding regimen of cattle to their natural feeding times redirected the cattle away from dustgenerating behaviors and thereby decreased considerably aerial dust concentrations closer to legal limits.
The understanding of the behavior of feeder cattle can help in the management of feedlots in a more animal welfare friendly manner. The modification of the feedlot environment by providing, e.g., shade should not only improve the well-being of the animals but also the profit of the operation.||