Angus-sired Steers Research Articles

Foot scores of cattle 2. Relationships among measurements of feet from slaughtered steers from eight sire groups

Abstract Objective linear measurements were taken at slaughter on the front and rear feet excised from 87 Angus-sired steers by known sires and dams. Generally, means for front foot traits were similar to those for rear feet, including a difference of only 2.0° in angle of front v. rear foot. The repeatability of objectively measured traits was high (>0.76). Correlations between measures on adjacent digits were high (0.54 – 0.88), as were most correlations between data from front and rear feet. Coefficients of variation for pre-slaughter liveweight, hot-carcass weight, hoof horn length, and angle (of hoof away from the vertical) ranged from 5.9 to 8.00%, for sole length (measured underneath the hoof) 4.8 to 5.8%, and for foot circumference 2.8%. Sire group effects were the only significant source of variation for the 14 foot traits. Principal component analysis of the variance-covariance matrix showed that 85, 7, and 3% of the variation was accounted for by the first three components, mainly describing slaughter liveweight, hoof horn lengths, and sole (i.e., underside) lengths respectively. Heavier cattle had larger hooves, with an angle indicating 'feet positioned closer to the vertical than for average~ eight animals. One sire group was of particular mterest because the herd owners thought the sire himself was unsuitable for use because of poor feet. Small but significant structural effects were found in his progeny group. His progeny were the most deviant for only one trait (length of sole on rear feet, as measured from below), and that was in a negative direction, which was favourable.

Characterization of Biological Types of Cattle. VIII. Postweaning Growth and Carcass Traits of Three-Way Cross Steers

Postweaning growth data on 282 steers and carcass data on 275 steers produced by artificially inseminating (AI) yearling heifers of 12 crossbred groups (Hereford-Angus reciprocal crosses plus F1 crosses produced by mating Jersey, South Devon, Simmental, Limousin and Charolais sires to Hereford and Angus cows) to Hereford, Angus, Brahman, Devon and Holstein bulls were analyzed. For postweaning growth rate, Devon-sired steers were the slowest, Holstein-sired steers were fastest and Hereford-Angus- and Brahman-sired steers were similar and intermediate. Due to their large weaning weights, Brahman-sired steers were heaviest at 452 days, followed closely by Holstein and then Hereford-Angus-AI (Hereford and Angus sires used by artificial insemination) and Devon. Steers from Jersey cross cows had the lowest average daily gain, relative growth rate and 452-day weight. Steers from the other crossbred cows group had similar postweaning growth rates, but due to weaning weight differences, Simmental, South Devon and Charolais crosses had similar 452-day weights that tended to be heavier than those of Hereford-Angus and Limousin crosses. Carcass traits were analyzed once with carcass weight as a covariate and once with slaughter age as a covariate. The analyses produced similar results. Carcasses from Holstein-sired steers had the least fat cover, smallest percentage of kidney, heart and pelvic fat (%KHP), best yield grade, highest estimated percentage retail product and lowest conformation score. Devon-sired steers had the highest %KHP fat. Brahman-sired steers had the poorest yield grade and the lowest marbling score and quality grade. Hereford and Angus-sired steers had the most fat cover, poorest yield grade and lowest estimated percentage retail product but highest conformation, marbling and quality scores. Steers from Hereford-Angus and Jersey cross cows had the most fat cover, smallest longissimus area, highest %KHP fat, lowest yield grade and lowest percentage retail product. Steers from Jersey crosses also had the lowest conformation scores. Most other differences among cow sire breeds for carcass traits were small.