|Gregory, Keith - ARS COLLABORATOR|
|Koch, Robert - RETIRED,UNIV. OF NEBRASKA|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 27, 1999
Publication Date: N/A
Interpretive Summary: Beef cattle producers can choose from among many breeds when designing efficient crossbreeding systems. Objective characterization of breeds for a broad spectrum of economically important traits enables producers to make better breeding decisions. The Germplasm Evaluation Program at the U.S. Meat Animal Research Center was designed to achieve this objective. This report compares reproductive and growth traits of young females of the following diverse group of breeds: Angus, Hereford, Charolais, Shorthorn, Galloway, Longhorn, Nellore, Piedmontese and Salers. These breeds can also be compared indirectly to the 23 other breeds that have been (or are currently being) evaluated in other cycles of the Germplasm Evaluation Program. The breeds evaluated in this report differed in growth rate and in the age and weight at which they reached puberty. Age at puberty is important because it is associated with reproductive rate and production efficiency of beef cows at young ages. The comparisons provided in this report will help beef producers to select breeds with characteristics that are appropriate to their management systems and production environments.
Technical Abstract: Postweaning growth, puberty and pregnancy traits were evaluated on 783 F1 heifers sired by Angus, Hereford, Charolais, Shorthorn, Galloway, Longhorn, Nellore, Piedmontese and Salers bulls and out of Angus and Hereford dams in Cycle IV of the Germplasm Evaluation (GPE) Program at the U.S. Meat Animal Research Center. The Hereford and Angus sires included a sample of bulls born from 1982 to 1985 (80's HA) as well as reference sires born from 1963 to 1970 (REF HA) used in previous cycles of the GPE. Breed group of sire had a significant (P < .01) effect on age and weight at puberty, 200, 400 and 550 d weights, ADG from 200 to 400 and from 400 to 550 d and 550 d hip height, but did not significantly influence pregnancy rate. Sire breed group rankings (and corrected means) for age at puberty (d) were: Piedmon- tese (332), Shorthorn (338), Charolais (348), REF HA (348), Galloway (351), 80's HA (352), Salers (355), Longhorn (357) and Nellore (405). Sire breed group rankings (and corrected means) for weight at puberty (kg) were: Longhorn (283), Piedmontese (298), Galloway (305), REF HA (309), Shorthorn (329), 80's HA (330), Salers (338), Nellore (341) and Charolais (345). Sire breed group rankings (and least squares means) for 400 d weight (kg) were: Charolais (390), Shorthorn (384), Salers (380), 80's HA (374), Nellore (364), REF HA (356), Piedmontese (353), Galloway (348) and Longhorn (321), with differences > 11.5 kg significant. Sire breed group rankings (and least squares means) for 550 d weight (kg) were: Charolais (445), Salers (430), Shorthorn (429), 80's HA (422), Nellore (420), Piedmontese (401), REF HA (398), Galloway (389) and Longhorn (371), with differences > 11.7 kg significant.