51 Lean meat yield of Angus, Brahman and Charolais grain fed steers

Abstract Lean meat yield (LMY) is a key driver of profitability in the beef industry, and it is associated with muscling and feed efficiency (Pethick et al., 2021). No research has studied differences in LMY between British, Continental, and Tropical beef breeds fed for increasing days on feed. The objective of the present study was to compare LMY of Angus, Brahman and Charolais steers with increasing days on feed (DOF). The hypothesis was that Charolais have the greatest LMY throughout the feeding period due to being a later maturing, high muscling breed compared with Angus and Brahman. Angus (n = 30), Brahman (n = 30), and Charolais (n = 29) 12-18 mo-old steers were inducted with a body weight (BW) of 361 ± 5.3 kg, 355 ± 5.3 kg and 317 ± 5.3 kg, respectively. Six animals of each breed were randomly selected for slaughter at 50-d intervals until 200 DOF. Steers were allowed ad libitum access to water and feed (78% rolled barley, 13.76% CP, 12.15 ME MJ/kg DM). Body weight, hot carcass weight (HCW), and LMY were measured at slaughter. All components of the animal were collected, and carcass muscle, fat and bones physically dissected with knives and weighed separately. The LMY as % empty BW (EBW) was calculated as the weight of lean meat separated from the carcass divided by EBW. The LMY as % of HCW was calculated as the weight of lean meat separated from the carcass divided by HCW. Data was analyzed with a model containing the fixed effect of breed, DOF at slaughter, and their interaction. Breed, DOF and their interaction affected LMY expressed as both ratio to EBW and HCW (P 0.05). Charolais steers had the greatest LMY (% HCW) at 50, 100, and 150 DOF, but similar to Brahman at 0 and 200 DOF (P 0.05; Figure 1a). Angus steers showed the lowest LMY (% HCW) throughout all DOF (P 0.05) except at 50 DOF being similar to Brahman (P 0.05). Furthermore, Charolais had the greatest LMY (% EBW) from 50 to 200 DOF (P 0.05) but it was similar to Brahman at 0 DOF (Figure 1b; P 0.05). Angus had the least LMY (% EBW) throughout (P 0.05) but was not different to Brahman at 50 DOF. Brahman had intermediate LMY (% EBW and % HCW) between Charolais and Angus. Differences between beef breeds suggest that LMY should be considered as another factor to establish an accurate carcass value.