Meat quality of weaner steers adapted to a diet containing potassium humate in the feedlot

Abstract

The objective of the study was to determine the meat quality responses of weaner steers fed diets containing potassium humate (PH) in a feedlot. Twenty-two yearling male steers were randomly allocated to two treatments: control (n = 11), fed a standard feedlot diet and PH (n = 11), fed a standard diet with added PH (5.8g/kg feed). The steers were housed in individual stanchions, with each steer as the experimental unit. At the end of the feeding trial at Day 112, the steers were slaughtered and the m. longissimus thoracic et lumborum muscle was sampled for meat quality measurements. Results of the study showed that diet had no effect on carcass characteristics and meat quality measurements, apart from meat pH and shear force values. Meat pH decline was more pronounced in the control group and higher shear force values were observed in the control group (6.58 and 4.91 kg) than the PH group (5.12 and 4.14 kg) at Day 1 and Day 7 of measurement respectively. The total intramuscular fat (IMF) was higher (by 16%) in the PH- fed weaner steers compared with the control. With regard to saturated fatty acids (SFA), higher amounts of myristic acid and heneicosanoic acid were observed in the PH-fed steers than in the control. However, the control had higher amounts of eicosatrienoic acid and eicosatetraenoic acid. PH inclusion in steer diets could therefore provide an alternative growth promotant in the production of safe and healthier meat in the feedlot. Keywords: Carcass characteristics, fatty acids, nutritional indices, shear force