The Role of Fatty Acids in Ruminant Diets and Novel Feed Ingredients High in Omega– 3 Fatty Acids Fed in Feedlot Diets

Authors

Mitchell M. Norman, University of Nebraska-LincolnFollow

First Advisor

Andrea Watson

Second Advisor

Galen Erickson

Third Advisor

James MacDonald

Date of this Version

8-2021

Document Type

Article

Citation

Norman, M. M. 2021. The Role of Fatty Acids in Ruminant Diets and Novel Feed Ingredients High in Omega– 3 Fatty Acids Fed in Feedlot Diets. M.S. Thesis. Univ. of Nebraska, Lincoln.

Comments

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: August 2021

Copyright © 2021 Mitchell M. Norman

Abstract

A finishing study evaluated the performance, carcass characteristics and fatty acid profiles of steers fed four inclusions of a novel feedstuff Green Grass. Green Grass is a product comprised of sesame meal, giant kelp, cassava, and sorghum containing high concentrations of polyunsaturated fatty acids. No differences were observed in initial BW, final BW, BW gain, HCW, LM area, 12^th rib fat depth, calculated YG, or liver abscess %. Dry matter intake linearly increased as Green Grass inclusion increased in the diet. Steers fed Green Grass had lower G:F than control cattle, and steers fed 30% Green Grass had a lower marbling score. A linear increase in alpha linolenic acid was observed in steak samples, resulting in an increase of 304% comparing steers fed 30% Green Grass to control cattle. Linear increases of trans-unsaturated fatty acids, and omega-3 fatty acids were also observed in steak samples from steers fed increasing inclusion of Green Grass. Increasing Green Grass inclusion in the diet from 0 to 30% linearly improved omega-3 fatty acid concentration in beef.

A safety trial was completed by feeding a novel algal biomass to cattle. Cattle were individually fed 1 of 4 inclusions of Condensed Algal Residue Solubles (CARS). Increasing CARS inclusion in the diet quadratically increased DMI and ADG and linearly increased G:F. Net energy calculations demonstrated a linear increase in NE_m and NE_g as CARS inclusion increased. Out of 27 organs measured, 6 had differences due to treatment in absolute weight and weight as a % of BW. Out of 21 blood chemistry measures, 8 were impacted by treatment.

A digestibility study was conducted evaluating CARS fed in finishing cattle diets. Increasing CARS inclusion in the diet resulted in a linear decrease in dry matter and organic matter intake, with no effect on dry matter and organic matter digestibility. Replacing up to 10% dry rolled corn with CARS in diets with or without wet distillers grains had little effect on digestibility of finishing beef cattle diets.

Advisor: Andrea K. Watson