Performing Department
Animal Dairy & Veterinary Scie
Non Technical Summary
Approximately 85% of all U.S. beef cattle receive a hormone-based, anabolic implant, resulting in improved skeletal muscle growth and production efficiency. Although anabolic implants have been used in beef production systems for over 60 years, the cellular mechanism through which anabolic implants improve production is not fully understood. Further, little research has sought to understand how the hormones in anabolic implants impact metabolism within skeletal muscle, systemically, and also in the meat. It is important that we improve our understanding of how anabolic implants impact beef production and meat quality as we strive to enhance sustainability and overcome current challenges of beef production systems. In this research project, we will utilize state-of-the-art techniques to assess how different signaling pathways and metabolites are different in the skeletal muscle, blood and liver of beef cattle receiving anabolic implants with different hormone concentrations. We will also assess nutritive value of the meat that is produced. This research will provide important insight into how giving anabolic implants to cattle impacts growth, metabolism, and nutritive value of the meat. Ultimately, this information will help improve upon or find alternatives to the use of anabolic implants, resulting in increased efficiency for beef producers and improvements in consumer attitude towards beef products.
Animal Health Component
50%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Goals / Objectives
The objective of this researchis to determine how the primary hormones found in anabolic implants (trenbolone acetate (TBA) and estradiol (E2)) impact metabolism and abundance of metabolites in feedlot steers. Below are the 5 specific objectives that will be completed:1. Use protein sequencing to determine how TBA and/or E2 impact the skeletal muscle and liver proteome over time.2. Determine whether TBA and/or E2 impact the metabolome of the skeletal muscle, liver and serum over time.3. Understand how mitochondrial respiration within the skeletal muscle is altered following treatment with TBA and/or E2.4. Determine whether TBA and/or E2 alter the metabolome of the meat that is produced.5. Determine how the proteome, metabolome, and mitochondrial respiration relate to feedlot production and carcass quality.The live animal trial will begin approximately January 2025 and samples will be collected through June 2025. Samples will be collected to analyze proteome, metabolome, and mitochondrial efficiency. Proteomic and metabolomic analyses will happen in 2025 and 2026. Mitochondrial efficiency analyses will be completed in 2025. Data analysis will occur in 2027 and all results will be compiled and published in 2028.
Project Methods
Experimental design: One animal trial will be completed to generate all of the biological samples and data to complete all five objectives. This experiment will utilize 60 commercial Angus steers weighing approximately 800 pounds and that have not previously received any type of anabolic implant. These animals will be obtained from the Utah State University beef cattle herd and will be selected at weaning to ensure the group is as homogenous as possible. After weaning, all calves will be placed in the Utah State University feedlot and receive the same backgrounding ration that is typical for the Intermountain West region of the US (approximately 40% alfalfa hay, 35% cracked barley grain, 23% corn silage, and 2% mineral supplement, DM basis) until an average weight of 800 pounds is reached. At this time, all steers will be stratified by weight into one of four different treatment groups (n=15): 1) no implant, 2) TBA only implant (200 mg TBA; Finaplix-H, Merck Animal Health, Madison, NJ), 3) E2 only implant (25.7 mg E2; Compudose, Elanco Animal Health, Greenfield, IN), and 4) a combined E2/TBA implant (120 mg TBA + 24 mg E2; Revalor-S, Merck Animal Health). Upon initiation of the trial, steers will be weighed, ultrasounded, implanted, and stratified into one of four covered pens each equipped with two Vytelle® bunks to allow for determination of individual intake, feed efficiency, and feeding behavior. All steers will be fed a typical finishing ration for the Intermountain West region of the US including a "step-up" period where grain is increased 10-15% DM each week until a final ration consisting of approximately 82% rolled barley, 10% corn silage, 6% alfalfa hay, and 2% mineral (DM basis). Animals will be weighed and ultrasounded on day 0 and every 30 days after. Skeletal muscle from the longissimus dorsi muscle, liver and blood samples will be collected on days 30, 60 and 100. These dates have been chosen to assess how implants impact animal physiology throughout the feeding period. After the steers have been on trial for approximately 120 days, and once an average ribeye fat thickness (REFT) of 12 mm is reached, the steers will be shipped to a commercial harvest facility (Hyrum, UT). Individual carcass data will be obtained from the harvest facility. After grading, approximately one day after exsanguination, the loin from the left side of each animal will be collected and transported back to USU for metabolomic analysis. The proteome will be analyzed in the skeletal muscle and liver on days 30, 60 and 100 of the trial. The metabolome of the liver, skeletal muscle, and serum will also be analyzed on days 30, 60 and 100. In addition, the metabolome of the meat will also be analyzed. ?Mitochondrial efficiency will be analyzed on days 30, ?60 and 100 as well. All of these different procedures will be conducted followed previously published literature from the PI and the Co-PIs.