# Effect of high-roughage backgrounding duration on carcass traits and meat quality of young Nellore bulls

## TL;DR

This study found that backgrounding young Nellore bulls on high-roughage diets for up to 56 days does not harm meat quality or carcass traits, but longer durations negatively affect performance.

## Contribution

The study provides new insights into optimal high-roughage backgrounding durations for Nellore bulls in tropical beef production systems.

## Key findings

- Backgrounding for 84 days reduced carcass weight and yield but not meat quality for most parameters.
- Aging improved meat quality attributes like myofibrillar fragmentation and water losses.
- A 56-day backgrounding period is recommended to maintain efficiency and flexibility in production systems.

## Abstract

This study evaluated the effects of different high-roughage backgrounding durations (0, 28, 56, and 84 days) on carcass traits and meat quality of 36 young Nellore bulls (265 ± 5 kg initial body weight). After this phase, animals were finished on high-energy diets and slaughtered 154 days after the beginning of the trial. Carcass traits, meat quality, and aging effects (0, 7, and 14 days) were assessed. Data were analyzed using a completely randomized design with four treatments (backgrounding durations) and using a 4 × 3 factorial arrangement for variables evaluated across aging times. Average daily gain was greatest in non-backgrounded animals (1.12 kg/d) and lowest in those backgrounded for 84 days (0.62 kg/d). Prolonged backgrounding (84 days) reduced hot and cold carcass weights and yield, whereas no differences were observed among 0-, 28-, and 56-day groups. Most meat quality parameters, including pH, backfat, sarcomere length, exudate losses, shear force, lipid oxidation, and nitric oxide concentration, were unaffected by treatments. However, 84-day backgrounding increased meat and fat lightness (L*) and reduced meat hue angle. Aging improved myofibrillar fragmentation index (MFI) and altered water losses, lipid oxidation, nitric oxide, and color attributes. Muscle chemical composition (moisture, protein, fat, and ash) did not differ among treatments. Extending high-roughage backgrounding diets up to 56 days did not compromise performance, carcass yield, or meat quality. However, longer durations (84 days) negatively affected performance and carcass traits. Therefore, a 56-day strategy may represent a suitable option for maintaining efficiency while providing flexibility for tropical pasture-to-feedlot systems.