Date of this Version
The Professional Animal Scientist 20 (2004): 15-26
Breeds were compared for differences in BW (n = 56,731), heights (n = 51,407) and body condition scores (BCS, n = 56,371) of 2- to 8-yr-old cows from four cycles of the Germplasm Evaluation (GPE) Program at the U. S. Meat Animal Research Center (MARC). Angus, Hereford, and topcross cows from 22 breeds of sires were produced. The mixed model for repeated measures of BW, height, and BCS included random additive genetic and permanent environmental effects of the cow. Differences among crosses were significant for all traits. In general, BW, within cycle, was greater for cows sired by breeds of large size and low milk production (Chianina and Charolais) than for those of large size and moderate milk production (Maine Anjou, Salers, and Shorthorn), moderate size and moderate milk production (Angus and South Devon), moderate size and low milk production (Hereford), and small size and low milk production (Galloway and Longhorn). Breeds of moderate size and moderately high milk production (Pinzgauer, Red Poll, and Tarentaise) were even lighter. Cows with Jersey sires were separated from all other breed groups because of light BW. Cows with sires of British origin tended to be lighter than those of continental European origin. Cows with Bos indicus sires (Brahman and Nellore) ranked between other breeds of large and moderate size for BW or for BW adjusted for BCS. In general, adjustment for BCS did not alter rankings of breed groups for differences in cow BW. Differences among breed groups for height closely followed differences for BW.