Dietary High Oleic Soybean Oil: Growth Performance, Carcass Performance, and Meat Quality of Market Lambs

The objective of this study was to evaluate dietary high oleic soybean oil on the growth performance, carcass performance, and meat quality of market lambs. Spring born, weaned, crossbred wethers (n=20) of Dorset-Suffolk genetics weighing approximately 41.3kg were utilized and finished at the Illinois State University (ISU) Farm. Animals were utilized in accordance with ISU’s Institutional Animal Care and Use Committee approval (Protocol #105-6898). Wethers were individually housed in a randomized complete block design and fed 1 of 2 treatments with ten replications per each treatment for 84d. The treatments included a control diet (CON) which was a finishing-diet consisting of corn silage, cracked corn, dried distiller’s grains, soybean meal, and soybean oil. The experimental diet (HOS) consisted of corn silage, cracked corn, dried distiller’s grains, soybean meal, and high oleic soybean oil (3%). Diets were mixed once daily, and feed was offered twice daily. Feed refusal collection was implemented in 5d periods. Two-day weights were taken every 14d, averaged, and used to calculate Average Daily Gain (ADG), Average Daily Feed Disappearance (ADFD), and Gain to Feed (G:F). Following finishing, wethers were transported 463km for humane slaughter and fabrication under USDA-FSIS inspection. Standard USDA carcass data (quality and yield grade) were recorded. Statistical analysis was performed using the MIXED procedure of SAS to obtain LSMEANS. No differences were found for the growth performance measures of ADG, ADFD, or G:F (P > 0.05). No differences were found for hot carcass weight, cold carcass weight, and dressing percentage (P > 0.05). Wethers fed HOS exhibited a decrease in a* color value of the longissimus at the 12th rib junction (14.398 vs. 15.030; SEM = .218) (P = .027), with no differences in L* or b* values (P > 0.05). Percentage of metmyoglobin, deoxymyoglobin, or oxymyoglobin in the longissimus face at the 12th rib junction was not altered by treatment (P > 0.05). In this study, HOS inclusion did not impact standard growth and carcass characteristics in finishing wethers. However, further evaluation into the decreased redness value of the loineye in HOS-fed lambs is warranted.