Location: Livestock Issues Research
Project Number: 3096-32000-009-033-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Apr 5, 2021
End Date: Aug 31, 2024
Objective:
Our first objective is to develop a science-based management strategy to reduce the use of antimicrobials in high-risk beef cattle by individually identifying and selecting specific high-risk cattle for metaphylactic treatment at feedlot arrival based on a non-invasive measurement of their surface temperature using infrared thermography. Our second objective is to implement the science-based selective metaphylaxis strategy into a commercial feedlot setting.
Approach:
For objective 1, we plan to conduct a series of experiments using high-risk cattle to evaluate the use of surface temperature at various anatomical locations in differing environmental conditions and selective metaphylaxis strategies to reduce antimicrobial use and antimicrobial resistance prevalence at the Texas Tech University Burnett Center.
For experiment 1, we will evaluate whether surface temperature measured using infrared thermography correlates with rectal body temperature. Surface temperatures will be collected at the 1) nasal planum; 2) orbital of the eye; 3) tip of the ear; and 4) tailhead in a minimum of 30 morbid and 30 healthy animals, in addition to rectal temperatures. By comparing morbid and healthy animals, we will also determine the ideal surface temperature where selective metaphylaxis can be implemented. The surface temperatures will be collected 1) without allowing the cattle to rest once they have been moved to the working facility; 2) after the cattle have been allowed to rest once they are moved to the working facility; 3) when infrared thermography is applied in direct sunlight (i.e. when the chute is in direct sunlight); and 4) when infrared thermography is applied in the shade (i.e. when the chute is in the shade).
For experiment 2, we will evaluate whether the use of selective metaphylaxis reduces antimicrobial use in high-risk beef cattle without compromising animal health outcomes. At feedlot arrival, cattle will be administered 1 of 5 treatments: 1) negative control, no antimicrobial on day of arrival; 2) conventional metaphylaxis, all cattle in this treatment will be administered an antimicrobial; 3) random metaphylaxis, where 25% of the cattle will randomly receive an antimicrobial; 4) selective metaphylaxis, based on rectal temperature, where only cattle with a pre-determined (40 C) rectal temperature will be given an antimicrobial; and 5) selective metaphylaxis using non-invasive infrared thermography, where only cattle with a predetermined (from experiment 1) surface temperature will receive an antimicrobial.
For experiment 2 approximately 48 steers will be used per treatment.Antimicrobial use, morbidity, and mortality will be recorded for each treatment. Additionally, fecal samples will be collected in experiment 2 from individual animals to evaluate the prevalence of antimicrobial resistant Enterococcus, E. coli, and Salmonella before and after metaphylactic administration and longitudinally until the day of harvest.
For objective 2, we plan to evaluate the use of selective metaphylaxis through infrared thermography in a commercial feedlot setting in collaboration with Hy-Plains Feedyard and Veterinary Research and Consulting Services.
We will use the knowledge gained from experiments 1 and 2 that comprise objective 1 and evaluate the use of selective metaphylaxis via infrared thermography in a commercial feedlot setting. After determining the best anatomical location on the animal and the most effective environmental conditions to use infrared thermography, we will evaluate ways it could be automated in the working facility and applied as a diagnostic tool to identify febrile illness.
