Effects of Steam Flaked Corn on Growth Performance, Carcass Characteristics, and Gastrointestinal Tract Health in Feeder Lambs

The objective of this study was to evaluate the influence of corn grain processing methods, steam-flaking and dry-rolling, on growth performance, carcass characteristics, and gastrointestinal tract (GIT) health in feeder lambs. Polypay wethers (n = 32; initial body weight = 29 ± 14.3 kg) were allocated to 16 pens (2 lambs/pen). Two treatments were assigned, (8 pens per treatment): 1) finishing diet with steam flaked corn (SFC) and 2) finishing diet with dry-rolled corn (DRC). Lambs were fed for 63 d, twice daily on equal proportions, at 0900 and 1700 hours. Ad libitum intake was achieved by offering 10% more feed than consumed the previous day. On d -2, lambs were vaccinated with a booster dose of clostridium perfringens types C&D and clostridium tetani. Lambs were weighed on days 0, 21, 42, 63, 64, and 65. Lambs were harvested over two days (4 replicate pens per treatment each day) at South Dakota State University Meat Laboratory (Brookings, SD). The model contained treatment as a fixed effect and block as a random effect, with pen as the experimental unit. Categorical data were analyzed as multinomial proportions. No difference between treatments were observed for growth performance variables (P ≥ 0.31). The empty gut weight of the DRC-fed lambs tended to be heavier than the SFC-fed lambs (P = 0.06; 5.8 and 5.3 kg, respectively). Lambs receiving SFC tended to have less healthy ruminal tissue and more severe ruminal lesions compared to those receiving DRC treatment (P = 0.09; 23.1 vs 60.7% healthy rumens, and 12.4 vs 2.7% of severe rumen lesions, for SFC and DRC, respectively). No other live performance measures, carcass characteristics, or digestive health metrics were affected by dietary treatments (P ≥ 0.14). Results of this study suggest steam-flaking corn in replacement of dry-rolled corn offers no additional performance benefits and can have negative consequences on GIT health.