PSV-15 - Environmental factors and management practices do not impact histone toxicity resistance or complement activity of bulls

Tuesday, July 18, 2023

1:30 PM – 2:45 PM MT

Location: 140 Aztec/110 Galisteo

Presenting Author(s)

Luis Ochoa

Graduate Student- Research Assistant
New Mexico State University
El Paso , Texas, United States

Author(s)

MW

Marcy Ward

Extension Livestock Specialist
New Mexico State University
Las Cruces, New Mexico, United States
JD

Jeffrey Dominguez Arellanes

New Mexico State University
Las Cruces, New Mexico, United States
Jennifer A. Hernandez Gifford

Associate Professor
New Mexico State University
Las Cruces, New Mexico, United States
CG

Craig A. Gifford

Extension Beef Cattle Specialist
New Mexico State University
Las Cruces, New Mexico, United States

Abstract: Bovine respiratory disease (BRD) is the most significant health problem associated with weaned and newly received cattle in the beef industry. Despite decades of research and development of better vaccine technology, BRD rates are on the rise. Work in our lab has developed novel technology to evaluate susceptibility to toxicity by extracellular histones and complement activity, which corresponds with susceptibility to severe cases of respiratory disease. Furthermore, we established interaction of the liver-derived compliment proteins with extracellular histones to presumably modulate histone toxicity. The liver synthesizes complement and other immune proteins and is also pivotal in animal metabolic efficiency; it is reasonable to speculate that diet, efficiency, or other environmental conditions could impact the serum test for extracellular histone toxicity, limiting the test’s ability as a selection tool for cattle. A contemporary group of ninety bulls composed of various breeds (Angus, Hereford, Braunvieh, Saler, and Simangus) was fed using the GrowSafe system at the Tucumcari Bull Test for 122 days. Residual feed intake (RFI), ADG, weight per day of age (WDA), and feed efficiency (FE) were calculated. To measure susceptibility to extracellular histones and complement activity (NMSU’s Respiratory Resistance Test), serum was harvested via coccygeal venipuncture and centrifugation at 1,200 x g for 15 min. The respiratory resistance test (RR) value as well as RFI, ADG, WDA, and FE were analyzed using the PROC CORR procedure of SAS. All procedures were approved by NMSU’s IACUC (2302000182). No correlation was found between RR, RFI, ADG, WDA, and FE (P < 0.10 for each variable). This suggests that an animal’s ability to protect against extracellular histones is not altered by environmental influences or efficiency indicating RR may be used as a selection tool for sires resistant to severe cases of respiratory disease.