Breed means for average daily gain, feed conversion and intake of beef bulls during postweaning feedlot performance tests.

Abstract

Comparisons of ADG, feed/gain, daily feed intake and daily feed intake as percentage of body weight may be important to beef cattle producers and researchers in breed selection and computer modeling. Data evaluated were postweaning feedlot performance test records collected from 1967 to 1986 of 3,661 individually fed bulls. Bulls originated from University of Arkansas purebred herds, Fayetteville, and the University of Arkansas Cooperative Bull Tests at Fayetteville, Hope and Monticello. Data were analyzed separately for years 1967 to 1976 (P1) (n = 1,654) and 1977 to 1986 (P2) (n = 2,007). Breeds in P1 were Hereford (HH), Angus (AN), Charolais (CH), Polled Hereford (HP) and Santa Gertrudis (SG). Breeds in P2 were HH, AN, CH, HP, SG, Simmental (SM), Maine-Anjou (MA), Brangus (BN) and Beefmaster (BM). The model fitted included initial age, breed and test number (all P less than .01 except for initial age on ADG in P1). Test number included variation of year, location and season. Breed rankings from highest to lowest for ADG in P1 were CH, SG, HH, HP and AN and in P2 were MA, CH, SM, AN, HP, SG, HH, BN and BM. Breed rankings from highest to lowest for feed/gain in P1 were AN, SG, CH, HP and HH and in P2 were BM, BN, AN, SG, HP, SM, HH, MA and CH. Breeds highest to lowest for daily feed intake (as-fed basis) in P1 were CH, SG, AN, HP and HH and in P2 were SM, MA, CH, AN, BN, HP, SG, HH and BM.(ABSTRACT TRUNCATED AT 250 WORDS)

Phenotypic and genetic parameters for different measures of feed efficiency in different breeds of Irish performance-tested beef bulls

“…The ranking of the breeds for FCR and ADG in the present study support the results of Chewning et al (1990) in their analysis of 2,007 performance-tested bulls, although no LI animals were included in their study. The ranking of the breeds for ADG in the present study also corroborates the findings of Schenkel et al (2004), although their ranking of breeds for FCR was slightly different, with AN ranking better than SI.…”

The effect of breed and individual heterosis on the feed efficiency, performance, and carcass characteristics of feedlot steers1

“…Residual feed intake estimates in the present study were improved (P = 0.05) as a result of direct breed effect with AN having a RFI of 0.15 and SM having the more favorable at -0.08. It has been shown in the literature that purebred AN cattle rank poorer for RFI compared to SM cattle (Crowley et al, 2010;Chewning et al, 1990;Schenkel et al, 2004). Feed conversion ratio also tended to improve (P = 0.09) a result of SM direct breed effect.…”

“…Feed efficiency measures are moderately heritable, between 0.21 and 0.56, and therefore have selection potential (Nkrumah et al, 2007). Feed efficiency measures including residual feed intake (RFI) and residual BW gain (RG) have also been shown to vary with breed type (Crowley et al, 2010;Chewning et al, 1990;Schenkel et al, 2004). Research to date has not shown any benefit of heterosis as it relates to feed efficiency of cattle; however, only G:F and to a minimal extent RFI have been evaluated (Gregory et al, 1966;Elzo et al, 2009;Rolfe et al, 2011).…”

Effects of 84-, 112- and 140-day postweaning feedlot performance tests for beef bulls.

“…However, it seems that some differences may exist among breeds. The comparison of breed means for these traits merits a separate study (Chewning et al, 1990). This suggests that most bulls within all breeds reached the upper inflection point of their growth curve (i.e., the point at which the animal is approaching maturity [Boggs and Merkel, 19841) before d 112.…”