Evaluation of quality grade indicators for live slaughter cattle

Date

1999-05

Journal Title

Journal ISSN

Volume Title

Publisher

Texas Tech University

Abstract

Understanding the relationship between live quality grade indicators and marbling score within and across breeds of slaughter cattle is imperative for profitable beef production. Thus, 1,138 slaughter cattle were evaluated live by a four-member, experienced, well-trained, USDA livestock grading team for the association between degree of finish at different anatomical locations and carcass marbling score. The live cattle were individually evaluated for degree of finish at these anatomical locations: cheeks, jowl, brisket, flank, cod/udder, tail pones, turn over the top, fat thickness, round creases, and lower quarter, and for overall USDA quality grade. Also, the cattle were scored for frame size, neck length, body depth, forearm muscle, disposition and two unique traits, dewclaws angle and facial hair swirl location. All of the live traits associated with fatness accounted for 20 to 25% (P < .05) of the variation in marbling score. Larger-framed, deeper-bodied, lighter-muscled cattle that were more docile tended to have more marbling (P < .05).

Live cattle graders can predict marbling score with about 75-80% accuracy within a third of a quality grade. Graders were most accurate on Brahman and Brahman X Exotic breed types, because of the narrow range of quality grades found in these breed types. The English-breed type was the most difficult, because of the wide range of quality grades within this breed. The Brahman-breed type needed the most fat in order to grade equally as well as other breeds, while the Dairy breed needed less fat than other breeds.

Live cattle representing each breed type and each quality grade were selected by the USDA live cattle grading team to produce a training videotape in conjunction with CEV Multimedia. The training videotape developed in this study will allow USDA live animal graders and others to improve their accuracy, speed and efficiency in the prediction of quality grades.

Visual evaluation of quality indicators of live cattle is fast, inexpensive, and relatively accurate. The training videotape developed in this study will allow USDA live animal graders and others to improve their accuracy in the prediction of quality grades.

Description

Keywords

Beef cattle -- Grading -- Evaluation, Cattle -- Carcasses -- Grading, Beef cattle -- Judging -- Evaluation

Citation