156 - Effect of Increasing Levels of Ergot Alkaloids in the Diet of Feedlot Cattle

Tuesday, June 28, 2022

10:30 AM – 10:45 AM CT

Location: Oklahoma City Convention Center, 302A

Presenting Author(s)

Jenna M. Sarich, B.Sc.

Graduate Student
University of Saskatchewan
Craik, Saskatchewan

Author(s)

KS

Kim Stanford

University of Lethbridge
Lethbridge, AB
KS

Karen S. Schwartzkopf-Genswein, PhD, MSc

Principle Research Scientist
Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada
Lethbridge, AB
Tim A. McAllister, n/a

Research Scientist
Agriculture and Agri-Food Canada
Lethbridge, AB
BB

Barry R. Blakley

University of Saskatchewan
Saskatoon, SK
Gregory B. Penner, Ph.D., M.Sc., B.Sc.

Professor
Department of Animal and Poultry Science, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada S7N 5A8
Saskatoon, SK
Gabriel O. Ribeiro, n/a

Assistant Professor
Department of Animal and Poultry Science, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada S7N 5A8
Saskatoon, SK

Abstract: This study evaluated the effects of feeding ergot alkaloids (EA) at increasing levels (0, 0.75, 1.5, and 3.0 ppm) to feedlot beef cattle over backgrounding (BG) and finishing (FS) phases on growth performance and carcass quality. Steers (n=240; 280±32 kg) were blocked by weight and randomly allocated to 16 pens (4 pens/treatment; 15 steers/pen). Treatments included: no added EA (CTL); or EA added at 0.75 (EA075); 1.50 (EA150); and 3.0 ppm (EA300). Steers were fed barley-based BG diets containing 40% concentrate:60% silage (DM basis) for 84 d, then stepped up over 28 d to a 90% concentrate:10% silage (DM basis) FS diet for 119 d. Steers fed EA300 received CTL in FS after 77 days on feed (DOF). In the BG phase, a quadratic decrease (P=0.05) in ADG and a linear decrease in final BW (P=0.03) and total BW gain (P=0.02) were observed with increasing EA. In the FS phase, up to 77 DOF, there was a linear decrease in steers DMI (P=0.04), ADG (P=0.01), and total BW gain (P=0.01) with increasing levels of EA. Over the full FS phase (119 DOF), a quadratic response was observed for ADG (P=0.05), final BW (P=0.05), total BW gain (P=0.02) and carcass weight (P=0.05) with steers fed EA150 showing the lowest performance. Gain:feed was not affected (P>0.20) by EA in the BG or FS phase. Dressing percentage (P=0.02) showed a quadratic effect with EA300 being the lowest. Additionally, a linear increase in lean meat yield (P< 0.001) was observed with increasing EA. Including EA in the diet promoted a linear increase in rectal temperature (P< 0.01). In conclusion, increasing levels of EA in the diet reduced growth performance, but when EA was removed, steers showed compensatory weight gain.