Dietary high-oleic-acid soybean oil: Effects on growth performance, carcass characteristics, and meat quality of lambs

Objective: The objective of this study was to evaluate the effect of dietary high-oleic soybean oil (HOS) on the growth performance, carcass traits, and meat quality of lambs. Materials and Methods: Spring-born, weaned, Dorset-Suffolk wethers (n = 20; average initial BW of 41.3 kg) were fed at the Illinois State University farm. Individually housed wethers were blocked by BW in a randomized complete block design and fed 1 of 2 treatments with 10 replications per treatment for 84 d. Treatments included a corn silage-based finishing diet (control) and control + 0.5% high-oleic soybean oil. Lambs were weighed on 2 consecutive days every 14 d. Average weights were used to calculate ADG, DMI, and G:F. Following finishing, wethers were transported 463 km for humane slaughter and fabrication under USDA-Food Safety and Inspection Service inspection. Standard USDA carcass data (QG and YG) were recorded. Statistical analysis was performed using the MIXED procedure of SAS to obtain least squares means. Results and Discussion: No differences were found for the growth performance measures of ADG (P = 1.0), DMI (P = 0.84), or G:F (P = 0.93). No differences were found for hot carcass weight (P = 0.941), cold carcass weight (P = 0.889), and DP (P = 0.931). Wethers fed HOS exhibited a decrease in a* color value of the longissimus at the 12th rib junction (P = 0.027), with no differences in L* (P = 0.760) or b* values (P = 0.347). Metmyoglobin (P = 0.917), deoxymyoglobin (P = 0.120), or oxymyoglobin (P = 0.077) percentage in the longissimus face at the 12th rib junction was not altered by treatment. Applications: In this study, HOS inclusion did not affect standard growth or carcass characteristics in wethers. However, further evaluation into the decreased redness value of the loin eye in HOS lambs is warranted.