Animal Science, Department of


First Advisor

Andrea K. Watson

Date of this Version


Document Type



Gibbons. 2021. Evaluation of Condensed Algal Residue Solubles as an Ingredient in Cattle Finishing Diets and its Effects on Digestibility and Fatty Acid Flow and a Comparison of Single and Dual Implant Strategies in Finishing Heifers. University of Nebraska.


A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In partial Fulfillment of Requirements For the Degree of Master of Science, Major: Animal Science, Under the Supervision of Professor Andrea K. Watson. Lincoln, Nebraska: April 2021

Copyright © 2021 J. Calvin Gibbons


Two experiments, a performance study (Exp. 1) and digestion study (Exp. 2) were conducted to evaluate a novel liquid feed, condensed algal residue solubles (CARS), in feedlot diets. In Exp. 1 and Exp. 2, steers were fed three inclusions of CARS at 0%, 2.5%, 5%. There were quadratic responses for greater carcass adjusted final BW, ADG, G:F, HCW, 12th rib fat, and yield grade. There was a linear increase in marbling score and a linear decrease in DMI and LM area as CARS increased. In Exp. 2, CARS did not affect intake or digestibility. Fatty acid flow at the duodenum was unaffected as CARS increased in the diet, though the fatty acid profile changed, with a linear increase of unsaturated and omega-3 fatty acids. Including CARS up to 2.5% of the diet DM improved feed efficiency. The CARS can effectively be included in feedlot finishing diets without affecting digestibility while influencing duodenal fatty acid flow composition.

Experiment 3 compared the effects of a single implant strategy utilizing a partially coated, long release heifer implant to a three non-coated implant strategy over an average of 215 d. Treatments included Revalor-XH or Revalor-IH, followed by Revalor-H followed by Revalor-200. There were no significant differences between treatments for live or carcass adjusted final BW, DMI, ADG, or G:F. There were no significant differences between treatments for HCW, 12th rib fat, dressing percent, or calculated yield grade. Heifers that received Revalor-XH, when fed 215 d, perform similarly to heifers on a 3-implant Revalor-IH/H/200 program.

Advisor: Andrea K. Watson

Included in

Beef Science Commons