Effects of vitamin and mineral premix withdrawal from diets on carcass and meat quality of feedlot steers.

Abstract

The primary objective of the present study was to assess the effects of vitamin and mineral premix (VMP) withdrawal from the diets 30 and 60days ahead of slaughter on carcass and meat quality of Holstein Friesian steers. A total of 45 animals at 16 to 17months of age were used and the selected animals were divided into three experimental groups: control group (fed with a diet with VMP), VMP withdrawal 30days ahead of slaughter (VMP30 group), and VMP withdrawal 60days ahead of slaughter (VMP60 group). Meat samples were taken at 24h postmortem from the 13th rib section and meat quality was evaluated on the Longissimus dorsi thoracis (LT) muscle. After slaughter, carcass yield and meat drip loss, cooking loss, thawing loss, and shear force traits were determined. Meat pH and color parameters were measured at 24, 48, 72, 96, 120, and 144h of postmortem. The fatty acid composition in 13th rib section' adipose tissue was determined. The hot and cold carcass weights, carcass yield and chilling loss were not affected by the withdrawal of VMP from the diet. Withdrawal of VMP from the diets 30 and 60days ahead of slaughter did not have any significant effects on ultimate pH, drip loss, cooking loss, thawing loss, shear force, and meat color. Additionally, dry matter, crude protein, ash, fat contents, moisture-protein ratio of the meat samples, and fatty acid profiles were not affected by VMP30 and VMP60 treatments. It was concluded based on present finding VMP could be withdrawn safely from the diets 30 and 60days ahead of slaughter without any negative effects on carcass and meat quality traits of feedlot steers. Withdrawal of VMP may reduce feeding costs and environmental damages generated by animal breeding systems.