Effects of soybean oil plus additional forage and anabolic implant in finishing steers: feedlot performance, carcass composition, and meat quality

Abstract

One hundred twenty crossbred steers were allotted to six weight blocks. Within each block, steers were allotted to one of four pens in a randomized complete block design (5 head per pen, 24 total pens). Treatments were low forage control diets (LFC) or high forage diets supplemented with soybean oil (HFO), without or with anabolic implant in 2 × 2 factorial arrangement. As compared with LFC, HFO reduced dry matter intake and average daily gain, without affecting the gain:feed ratio. Feeding HFO also decreased dressing yield and backfat thickness, with no impact on the longissimus dorsi area and Warner-Bratzler shear force. Meat from steers fed HFO contained greater relative proportion of cis-9, cis-12 18:2, cis-9, trans-11 18:2, and cis-9, cis-12, cis-15 18:3 as compared with LFC. Implanted steers had greater dry matter intake, average daily gain, and gain:feed ratio. Implants improved dressing yield, tended to increase the longissimus dorsi area, decreased backfat thickness, and increased meat Warner-Bratzler shear force. Meat from implanted steers contained greater relative concentration of cis-9, cis-12 18:2 and cis-9, cis-12, cis-15 18:3, without affecting cis-9, trans-11 18:2, as compared with non-implanted animals. No interaction of diet by implant was observed for these variables.