|Olson, T - UNIVERSITY OF FLORIDA|
Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: January 15, 2006
Publication Date: February 15, 2006
Citation: Riley, D.G., Chase, C.C., Coleman, S.W., Olson, T.A. 2006. Comparison of pure and crossbred calves produced by brooksville angus sires and sires from prominent angus bloodlines for calf traits [abstract]. Journal of Animal Science.84(2): 9. Technical Abstract: Cows in the Brooksville Angus herd look much shorter than many modern Angus, among other apparent differences, and their appropriate representation of the breed in research has been questioned. The objective of this study was to compare performance of calves produced by sires born and raised in this closed herd (BKV) to calves produced by sires from unrelated modern Angus bloodlines (OUT). Angus, Brahman, and Romosinuano cows were mated to sires 4 yr and calves (n = 427) were born 2002 through 2005. Birth and weaning weight, ADG, hip height, and body condition score at weaning were evaluated. Binomial traits were the proportion of difficult births, expressing poor vigor at birth, and mortality prior to 3 d age and before weaning. Fixed effects included sire source, dam breed, dam age, and year. Calf age in days was a covariate. Random effects were sire nested within source. Sire source x dam breed means for binomial traits were compared to x2 expectation. Source of sire did not differ across cow breeds for birth or weaning weight, ADG, or body condition score (P > 0.71). Hip height for calves from OUT sires was 114.2 ± 0.5 cm, which was greater (P = 0.018) than calves from BKV sires (112.3 ± 0.6 cm). Within cow breeds, hip heights of calves from OUT sires and from Angus or Romosinuano dams were greater (2.3 and 2.1 cm, P = 0.02) and Brahman dams (1.5 cm, P = 0.14) than those from BKV sires. Calf mortality prior to 3 d for OUT-sired calves from Angus dams was 0.116 ± 0.04 and all others were less than 0.028; this was different from expectation (P = 0.02). Sire source x dam breed means for difficult births did not differ (P = 0.46) from expectation; however means for poor calf vigor and survival to weaning approached difference from expectation (P < = 0.12). Source of sire appears to be important for calf survival and hip height, but can be combined into a single category for the other traits. This effect must be investigated further in steer traits and cow reproduction traits.