Trained panel sensory evaluation of m. longissimus thoracis, m. gluteus medius and m. semimembranosus from Angus crossbred steers: the influence of hormonal growth promotants, ractopamine hydrochloride, and selection for high or low residual feed intake.

• Author / Creator

  Laguda,Olalekan.

• Selection of cattle for residual feed intake (RFI) does not affect rate of weight gain; rather, low RFI cattle consume less feed than high RFI animals to attain a similar final body weight and are thus considered feed efficient. Reducing production costs by selecting low RFI cattle and incorporating hormonal growth promotants (HGP) or beta-adrenergic agonists (BA) into beef production programs will only be beneficial to the beef industry if meat quality is not adversely affected. Trained sensory panelists evaluated the meat quality characteristics of m. longissimus thoracis (LT), m. gluteus medius (GM), and m. semimembranosus (SM) from carcasses of Angus crossbred steers treated with HGP and/or BA and selected for high or low RFI. Forty-eight Angus crossbred steers, 21 high RFI and 27 low RFI, were either implanted twice with HGP (treated) or not (control) and received either ractopamine at 200 mg/head/day for the last 28 days of finishing (treated) or not (control) in a 2 x 2 x 2 factorial design. Half of each muscle, balanced for position within the muscle, was aged under vacuum in polypropylene bags for either 3 or 12 days post-mortem before assessment for sensory characteristics. Overall tenderness scores for all the samples were rated as tender, but aged samples were rated highest for overall tenderness. The results further showed that steaks from animals that were treated with HGP were the toughest, while steaks from animals that were either treated with ractopamine hydrochloride (RAC) or not treated produced the most tender beef regardless of muscle type. A similar relationship was observed for juiciness with HGP steaks the least juicy by the panelists while steak from steers with no treatment or only RAC were the juiciest.

• Subjects / Keywords

  • Steroids
  • Ractopamine
  • Residual feed intake.

• Graduation date

  Fall 2019

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-91qa-3b17

• License

  Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.