Abstract #T72

# T72
A comparison of Dorper and blackface lambs in growth and carcass performance.
Kayley R. Wall*1, Chris R. Kerth1, 1Texas A&M University, College Station, TX.

To determine the suitability of a purebred Dorper as a meat animal in a production setting, the growth and carcass traits of blackface April–born lambs (n = 8) grown on a concentrate diet were compared with Dorper September–born lambs (n = 8). All lambs were fed a concentrate diet (16%CP, 3% Crude Fat, 9% Crude Fiber) ad libitum in separate pens for 18 d before the start and for the duration of the study (62 d). The initial (0 d) and final (62 d) BW, percent change in BW, ADG, and G:F were measured. One blackface lamb died during the feeding trial. All of the lambs were harvested on d 62 and placed into the blast chiller (4°C) for 15 h after hot carcass weights were recorded. Carcass data were collected 16 d post-mortem. The carcasses were ribbed and allowed to bloom for one hour before marbling, fat thickness, LM area, leg confirmation score, KPH %, flank streaking, and lean color (L*, a*, and b*) were collected. Data were analyzed using a one-way ANOVA of a completely randomized design with animal as the experimental unit and α set at 5%. Average daily gain and G:F were not affected (P > 0.47) by lamb breed, but percentage change in BW tended (P = 0.099) to be higher in Dorper sheep compared with blackface sheep. Fat thickness, marbling, flank streaking and KPH % were higher (P < 0.014) in the blackface than Dorper lambs. The blackface lambs also had heavier (P < 0.001) live and hot carcass weights than the Dorper lambs; however, there were no significant differences (P > 0.13) between the breeds in LM area and dressing percentage, despite the age difference of the lambs. Dorper lambs had lighter (higher L* values; P = 0.001) and less red (lower a* values; P = 0.041) lean, but b* values were not affected (P = 0.62) by breed. Although the blackface lambs were fatter and had higher BW and HCW compared with the Dorper lambs, they did not outperform them in growth, dressing percent, or LM area. We believe the Dorper could be a suitable competitor to the blackface in a production system as a meat-producing animal.

Key Words: Dorper, lamb