Abstract
This study evaluated the effect of feeding pelleted or mash ergot contaminated grain fed continuously or intermittently on the growth performance, blood serum variables, and carcass quality of finishing beef steers. Sixty black angus steers (442 ± 36.7 kg) were used in a complete randomized finishing (90% concentrate:10% barley silage DM basis) 126-d study. Steers were randomly assigned to 4 different treatments and individually housed. Treatments included: 1) control ration [CON; no added ergot alkaloids (EA)], 2) continuous ergot mash (CEM; fed continuously at 2 ppm total EA), 3) intermittent ergot mash (IEM; fed at 2 ppm EA during the first week of each 21-d period and control diet for the remaining 2 weeks), and 4) intermittent ergot pellet (IEP; fed at 2 ppm EA incorporated into a pelleted supplement during the first week of each 21-d period and control diet for the other 2 weeks). Steers were weighed every 21 d and blood samples were collected on day 0, 42, 84, and 126. Steer DMI (P < 0.01, 9.95 vs. 11.05 kg/day) and ADG (P = 0.04) decreased for all EA treatments compared with the CON. Total shrunk BW gain (P = 0.03, 202.5 vs. 225.2 kg), final BW (P = 0.03, 617.9 vs. 662.2 kg), and carcass weight (P = 0.06) decreased for all EA steers compared with the CON steers. No treatment effects (P > 0.05) were observed for carcass dressing percentage, ribeye area, marbling score, or liver abscess. The percent of carcasses graded AAA decreased for all EA steers compared CON steers (P < 0.01, 46.7 vs. 93.3%). Steers fed EA had increased rectal temperature compared with CON steers (P < 0.01, 39.8 vs. 39.4 °C). Hair cortisol concentrations were less in steers fed IEP (P = 0.05, 1.23 vs. 1.76 pg/mg) than CON. No treatment effects (P > 0.05) were observed for complete blood count, and serum prolactin, haptoglobin, albumin, alkaline phosphatase, alanine transaminase, amylase, calcium, creatine, glucose, lipase, total bilirubin, total protein, or globulin. Blood urea nitrogen was less for EA steers compared with CON (P = 0.01, 3.48 vs. 4.10 mmol/L). The IEM steers had decreased concentrations of serum gamma-glutamyl transferase compared with IEP steers (P = 0.04, 23.4 vs. 28.5 IU). Pelleting ergot contaminated grain did not reduce the impact of ergot alkaloids on any of the measured parameters. Results suggest that continuously or intermittently feeding an ergot contaminated diet (2 ppm EA) can significantly reduce intake, growth performance, and carcass weight, with minimal impact on blood serum variables in finishing steers. Pelleting was not an effective method of reducing ergot toxicity.