Effects of conventional and natural management systems on backgrounding and finishing performance of beef steers

Objective

This study evaluated 2 beef cattle manage- ment strategies, conventional (CONV) or natural (NAT), for 3 BW groups at weaning to evaluate growth perfor- mance during backgrounding and finishing and carcass characteristics.

Materials and Methods

A total of 240 weaned steers, free of preweaning implants, were allocated into heavy (HV) (290 ± 21 kg; mean ± SD), medium (MD) (247 ± 8 kg), or light (LT) (214 ± 15.6 kg) weight groups over 2 yr. Each weight group (n = 80) was randomly allo- cated to 1 of 2 treatments (n = 40): either conventional or natural (n = 4). Conventional treatments used hormonal implants and feed additives, but the natural treatment did not. Following a 41-d receiving phase, HV steers entered direct finishing, MD steers entered a short backgrounding and finishing, and LT steers entered a long backgrounding, grazing, and finishing, all fed to a shrink weight of 620 kg.

Results and Discussion

Steer ADG was 19% and 22% greater for MD- and LT-CONV, respectively, at backgrounding, compared with NAT. The G:F was 20% greater for HV- and MD-CONV at finishing and 25% greater for LT-CONV at backgrounding. The HV-, MD-, and LT-CONV took 50, 71, and 59 fewer days on feed, respectively, to finish, relative to NAT. The rib-eye area were greatest in HV-CONV, and NAT produced greater marbling, QG (AAA), and backfat thickness and had a greater proportion of liver abscesses.

Implications and Applications

Steers managed without performance-enhancing technologies under west- ern Canadian conditions will have lower ADG, G:F, and YG1, but greater days on feed to a target weight, AAA grade, marbling, and backfat thickness, than convention- ally-managed steers.