|Vann, Rhonda - MISSISSIPPI STATE UNIV|
|Burdick, Nicole - TEXAS A&M UNIVERSITY|
|Loyd, Andrea - TEXAS A&M UNIVERSITY|
|Caldwell, Lisa - TEXAS A&M UNIVERSITY|
|Randel, Ron - TEXAS AGRILIFE RESEARCH|
|Welsh JR., Tom - TEXAS A&M UNIVERSITY|
|Willard, Scott - MISSISSIPPI STATE UNIV|
Submitted to: Beef Cattle Research in Texas
Publication Type: Proceedings
Publication Acceptance Date: September 1, 2008
Publication Date: N/A
Interpretive Summary: A collaborative study was conducted involving scientists from the Livestock Issues Research Unit, Mississippi State University, Texas A&M University, and the Texas AgriLife Research Center in Overton, TX, to determine the influence of temperament of bulls on ultrasound body composition traits in response to transportation and an immune challenge. For this study, 24 yearling Brahman bulls were transported 770 km from Overton, TX, to New Deal, TX. Prior to transportation (departure), after transportation (770 km), and following the immune challenge body weights and ultrasound of live animal body composition traits for ribeye area, rib fat, percent intramuscular fat and rump fat were collected. The results from this study indicate that transportation stress negatively impacts body composition traits, especially intramuscular fat in young steers transported to the feedlot or bulls undergoing transportation and an endotoxin challenge. These changes are minimal in younger growing animals, however, the trend is evident and further research is needed to elucidate these changes. This would also indicate that fat cattle transported long distances to a harvest facility could undergo the same type of changes in percent intramuscular fat, and thus could have an impact on cattle marketed on a grid system. The results of this research will be of particular interest to beef cattle feedlot managers, veterinarians managing the health of feedlot cattle, and scientists, whether from industry, academia, or industry working in the area of beef cattle production, health, and well-being.
Technical Abstract: This study was designed to determine the influence of temperament of bulls on ultrasound body composition traits in response to transportation and an endotoxin challenge. Purebred Brahman bulls were selected from a pool of 60 bulls based on temperament scores measured at weaning (n=8 each: calm, intermediate, and temperamental) in which temperament score was an average of exit velocity and pen score. Prior to transportation (departure), after transportation (770 km), and post-lipopolysaccharide (LPS) challenge, body weights and ultrasound live animal body composition traits for ribeye area, rib fat, percent intramuscular fat, and rump fat were collected. Body weight decreased (average 18.6 ± 5.5 kg) for all temperament groups from date of departure through post-LPS challenge. Temperamental bulls had a greater change in ribeye area from departure to post-LPS challenge. There was a tendency for Temperamental bulls to have the smallest decrease in percent intramuscular fat compared to calm or intermediate bulls due to transportation or post-LPS challenge. Rib fat was reduced (average 0.015 ± 0.009 cm) due to transportation for bulls in all temperament classifications. Temperamental bulls had the smallest reduction in rib fat compared to calm or intermediate bulls post-LPS challenge. In summary, bull body weight and rib fat was reduced due to transportation and an endotoxin challenge via LPS administration.