Influence of source of origin and region of finishing on growth performance and carcass characteristics of finishing heifers fed in the United States

Authors: DEHAAN, ERIN - South Dakota State University; DORNBACH, COLTON - Texas Tech University; BLAIR, AMANDA - South Dakota State University; Sanchez, Nicole; Carroll, Jeffery; Broadway, Paul; RUSCHE, WARREN - South Dakota State University; HALES, KRISTIN - Texas Tech University; SMITH, ZACHARY - South Dakota State University

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/3/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Beef cattle are acquired from all regions of the United States, and most are finished in a feedlot for harvest. Feedlot practices can vary based upon the region of the United States. Cattle in the Northern Plains are often shipped to other regions, such as the Southern Plains, because of the limited feedlots available to finish cattle. Information about the relationship of the movement of cattle between regions with different production systems and ambient temperature on performance is lacking. A study was conducted by ARS scientists in Lubbock, Texas and university collaborators to evaluate the effect of region of finishing and region of origin on growth, health, and carcass characteristics. Data from this study found that growth in the feedlot was influenced by region of origin of the calves. Also, stress from transportation and movement to a region with greater temperatures may have affected carcass characteristics. However, further research is still needed. These data will be of interest to scientists in the fields of beef cattle production and health, and to beef producers.

Technical Abstract: The objective was to evaluate growth performance and carcass traits of finishing beef heifers sourced and finished in different geographical regions in the U.S. Yearling heifers [n = 190; initial body weight (BW) 483 ± 0.4 kg and 425 ± 1.9 kg for SD and TX sourced, respectively] were used in a 2 × 2 factorial arrangement of origin state (SD vs. TX) and finishing state (SD vs. TX). Heifers were allotted on d -1 into four treatments: 1) sourced from SD and finished in SD (SD-SD), 2) sourced from SD and finished in TX (SD-TX), 3) sourced from TX and finished in SD (TX-SD), and 4) sourced from TX and finished in TX (TX-TX). Heifers were weighed on d -1, 3, 15, 28, 56, 78 (TX-TX and SD-TX) and 90 (SD-SD and TX-SD). On d 0, SD-TX and TX-SD heifers were shipped to their respective finishing locations. The following morning (d 1), SD-TX and TX-SD heifers were individually weighed to determine transportation shrink. To monitor transportation stress effects, vaginal temperature probes were inserted into all SD-TX and TX-SD heifers and a portion of SD-SD and TX-TX heifers on d -1 and removed on d 3. Clinical attitude scores (CAS) were recorded on d -1, 0, 1, 2 and 3 for bovine respiratory disease symptoms. Transported heifers had decreased temperatures (P = 0.01) during transit and post-transit but had increased (P = 0.01) vaginal temperature during loading and unloading compared to non-transported heifers. On d 0, 1, and 3 there was a shift in the distribution of heifers that had a CAS score greater than 0 for TX-TX, SD-TX and TX-SD. Heifers endured elevated ambient temperatures (temperature humidity index value > 75) for 54% and 18% of the feeding period for TX and SD finished heifers, respectively. All cumulative growth performance measures and carcass trait interactions were different (P < 0.01) except for d -1 BW, percent shrink during transit, average daily gain, dressing percent, ribeye area and liver abscess severity, which did not differ (P > 0.30). There was a shift in the distribution (P < 0.02) towards a greater proportion of Yield Grade 1 and Select carcasses for heifers fed in TX than fed in SD. Overall, heifers transported to higher ambient temperatures had improved overall yield grades, but decreased dry matter intake, quality grades (QG) and limited growth recovery (45 kg SEM lighter) than non-transported heifers. Heifers transported to lower ambient temperatures recovered growth and had improved QG (P < 0.02) at the same thickness of rib fat compared to non-transported heifers but had decreased overall yield and yield grades.