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Effects of diet, housing and season systems on feedlot cattle finishing programs
A four-year study was conducted using yearling steers (n = 1,987; BW average weight was 318 kg) of mixed British breeds. The overall objectives of this study were to evaluate feedlot performance, carcass characteristics and expected economic projections when steers were placed on feed at the beginning of each season in different diet-housing systems. Diets were: 1) a mixture of processed high moisture corn grain (77% DM) and whole plant corn silage, 2) a whole plant corn silage diet (35% DM). In addition, protein, vitamin and mineral supplement was provided to meet dietary requirements. Housing consisted of: 1) shelter; open lot with access to overhead shelter, 2) no shelter; open lot without access to an overhead shelter, but provided with a windbreak, 3) confinement; open front-side confinement barn. PROC MIXED of SAS was used for analysis with pen (n =20) as the experimental unit. The effects of diet, housing, season, and year influenced ADG (P < 0.001), as well as the interaction of diet × season (P < 0.05), but did not affect dry matter intake (P > 0.05).The FE was affected by diet (P < 0.001), year and the interaction of diet × season (P < 0.05). The effects of diet, housing, season and year affected HCW and DP (P < 0.001). In addition, BF, KPH, YG and QG were affected by dietary treatment (P < 0.001) and season (P < 0.05), but not by the effects of housing (P > 0.05). Economic analysis showed that shelter corn (SC) steers had 3.2% higher income per head than those in shelter silage (SS) facilities. Moreover, steers in no shelter corn (NSC) groups had 3.9% better income per animal than cattle fed in no shelter silage (NSS). Besides, steers fed in confinement corn (CC) received 2.2% higher income per head compared to those fed in confinement silage (CS) system. Overall, SC steers had the highest income per head, with a 6% advantage over the CS group, which had the lowest income per head. Steers fed a corn-based diet had better returns than those fed a corn silage-based diet. Winter steers in NSS had the lowest income, which represented 7.4% difference between the highest incomes attained by steers in SC system. During spring and summer, the SC system had the highest income per steer, followed by NSC and then the CC group.
Keywords: cattle, feedlot performance, carcass characteristics, economics