Abstract
The use of 28 d average daily gains as predictors of carcass traits is a new concept in the beef industry. This procedure could benefit feedyard managers in optimizing the performance of cattle being fed and in lower discounts from the packers. The cattle evaluated were part of the Angelton Project and consisted of 3/4 Angus 1/4 Brahman cattle, 3/4 Brahman 1/4 Angus cattle, and F2 crosses (n = 440). These cattle are compromised of 35 full sib embryo transfer families and were evaluated over a five year period for growth and slaughter traits. The cattle were placed in simulated feedyard conditions for at least 140 d and weighed every 28 d for five periods to monitor gains and performance. After the feeding period was concluded, the cattle were slaughtered and data were collected. Among the traits measured were quality grade, marbling, and actual fat. The purpose of this study was to determine the viability and practicality of using the five 28 d average daily gain periods as predictors of carcass traits. The mean ADGs were calculated for the total population as well as by calf breeding code. The ADGs peaked at 56 d for the total population and for the 3/4 Angus 1/4 Brahman, and the 3/4 Brahman 1/4 Angus breed groups. Family code, birth weight, and average daily gain for period 3 (56 to 84 d) were the best predictors of quality grade while only family code and average daily gain for period 3 (56 to 84 d) were the best predictors of marbling. Effects of sire code nested within family code, sex, weaning weight, average daily gain for period I (O to 28 d), average daily gain for period 2 (28 to 56), and average daily gain for period 3 (56 to 84 d) were the best predictors of actual fat. If the breeding of an animal is known, then better gains at 56 d and 84 d can be expected to enhance potential quality merit of the carcass.
Drake, Leah Anne (1997). The potential use of 28-day average daily gains as predictors of carcass traits. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1997 -THESIS -D73.