Correlations between cattle disposition and meat quality were expected to be
found, as well as differences in meat quality traits among contemporary groups, sires,
and families nested within sires. Temperament effects on meat quality were evaluated in
Nellore × Angus F2 cross cattle (n = 238) over a 3-yr period, with harvests twice a year.
Five aspects of temperament -- aggressiveness, nervousness, flightiness, gregariousness,
and overall temperament -- were evaluated at weaning and yearling ages, as well as an
overall temperament score at slaughter. USDA quality grade, fat thickness, adjusted fat
thickness, hot carcass weight, USDA yield grade, and chemical fat were correlated
negatively (P < 0.05) with weaning temperament scores, aggressiveness, nervousness,
flightiness, gregariousness, and overall temperament. No significant correlation was
found between Warner-Bratzler shear and weaning temperament traits. USDA quality
grade and live weight were correlated negatively (P < 0.05) with yearling temperament
scores, nervousness, flightiness, gregariousness, overall temperament score as well as
the temperament score observed at slaughter. Fat thickness and adjusted fat thickness
also were correlated negatively (P < 0.05) with yearling gregariousness, yearling overall, and slaughter overall temperament. Yearling gregariousness was correlated
positively (P < 0.05) with Warner-Bratzler shear from both ES and NON carcasses.
Least squares mean differences were evaluated among contemporary groups, sires, and
families nested within sires for overall temperament traits and meat quality traits.
Contemporary group differences found were thought to be explained by environmental
factors, as seen in contemporary group 5, which had the smallest ribeye possibly caused
by the shortest feeding period. Steers sired by 297J had the lowest (calmest)
temperament scores, most 12th rib fat, highest numerical yield grade, and the heaviest
weights. Sire 437J had steers with the highest (wildest) temperament scores, the least fat
and lowest numerical yield grade. This population was designed to identify QTL for
economically important traits and appears to be useful for this purpose because of the
differences found both between and within families.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2869 |
| Date | 15 May 2009 |
| Creators | Nicholson, Kristin Leigh |
| Contributors | Savell, Jeffrey W. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | electronic, application/pdf, born digital |
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