|Chase, Chadwick - Chad|
Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: 12/16/2006
Publication Date: 2/6/2007
Citation: Arthington, J.D., Riley, D.G., Chase, C.C., Rae, D.O., Griffin, J.L., Coleman, S.W. 2007. Comparison of Florida-born, embryo-derived Angus calves sourced from Kansas and Florida herds on measures of performance, disposition, and body temperature from birth to weaning [abstract]. Journal of Animal Science. 85(2);Paper No. 7.
Technical Abstract: Florida's beef industry ranks first in the US for the number of ranches exceeding 500 cows. Angus bulls are commonly imported into Florida from northern states to supply the demand for herd sires. The objective of this study was to investigate the performance of two Angus genotypes derived from frozen embryos that were gestated in Brahman x British crossbred cows in south Florida. One genotype was derived from a Kansas herd and represents genetics that are considered modern in the Angus industry. The second genotype was derived from the USDA-ARS Station in Brooksville, FL and represents a mostly closed herd of Angus cattle that have been reared in Central Florida for over 60 years. A total of 81 calves were generated over three consecutive years comprising 16 and 20 Florida bulls and heifers and 26 and 19 Kansas bulls and heifers, respectively. Birth weight did not differ among genotypes (28.2 +/- 0.16 kg). Although age at weaning did not differ (267 +/- 4 d), Kansas calves had a greater (P < 0.01) hip height (109 vs. 105 cm; SEM = 0.74) and tended (P = 0.09) to have a greater body weight (229 vs. 217 kg; SEM = 4.9) at weaning compared to Florida calves, respectively. Three disposition scores collected at weaning (chute exit velocity and chute and pen temperament score) did not differ (P > 0.14) among genotypes. Tympanic temperatures collected over three consecutive July days revealed no differences (P > 0.36) among genotypes (average daily low and high tympanic temperatures = 38.5 +/- 0.11 and 40.9 +/- 0.07 oC, respectively). A hair coat score (1 to 5 scale; 1 = slick haired and 5 = excessive unshed hair) was collected at weaning and did not differ among genotypes (2.8 vs. 2.4 for Florida and Kansas calves, respectively; SEM = 0.33). Relative to calf performance, lowered body temperature during the summer, hair coat length, or disposition, these results suggest that there are no apparent differences due to the origin (temperate vs. tropical environment) of Angus embryos when gestated and reared to weaning in south Florida