Sustainable evaluation of tannin extract biomass as a feed product additive: effects on growth performance, meat fatty acid profile, and lipid oxidation in bullocks.

Bioactive ingredients are secondary metabolites produced in plants and are usually extracted and used for different purposes such as rumen fermentation and product quality improvement in animal nutrition. One of the bioactive ingredients is tannin from quebracho trees which could be used in livestock nutrition. This study was performed to evaluate the effect of supplementing a finishing diet with 0.3% (w/w DM) of quebracho tannin extract on lipid oxidation in meat derived from bullocks. Sixteen crossbred bullocks (Bostaurus x Bosindicus, with 422.71 ± 6.70 kg initial weight) were randomly assigned to receive one of the two treatments during the last 40 days in the feedlot and steers were fed on the finishing diet (CTRL) or same diet added with 0.3% (DM basis) of tannin extract (TE). The bullocks were slaughtered, and after 24 h chilling (4 °C), the left half of the carcass was cross sectioned between 12 and 13th ribs, and carcass traits were measured. The samples of longissimus thoracis muscle were taken and chemical composition and fatty acid profile were measured while TBARS was evaluated during 12 display days. The results were analysed as completely randomized design and each bullock was used as an experimental unit. Feedlot performance and carcass characteristics of bullocks were not affected by tannins addition (P > 0.05). Saturated fatty acids, monounsaturated fatty acids, n-6, and n-3 polyunsaturated fatty acids were also not affected by the tannin inclusion. Tannins decreased lipid oxidation at day 12 (P < 0.01) and did not affect (P > 0.05) other meat shelf life and chemical composition variables. Product of quebracho tannin extract had no effect on the feedlot performance, carcass characteristics, fatty acid profile of beef, pH, and colour of beef of intensively fattened bullocks. Notwithstanding, the results suggest that supplementing produced tannin extract at 0.3% of dietary DM could improve bovine meat shelf life by decreasing the longissimus thoracis thiobarbituric acid reactive substance kept during 12-day storage. [ABSTRACT FROM AUTHOR]