|Olson, T. - UNIVERSITY OF FLORIDA|
Submitted to: Journal of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: December 27, 2003
Publication Date: February 14, 2004
Citation: Riley, D.G., Chase, C.C., Coleman, S.W., Olson, T.A. 2004. Evaluation of romosinuano as straightbreds and crossbreds with angus and brahman: claf traits. Journal of Animal Science: Vol. 2, Suppl.2, pg.4. Interpretive Summary: The object was to evaluate Romosinuano for calf performance traits. Calves (n=708, born in 2002 and 2003) were Romosinuano (R), Angus (A), and Brahman (B) or crossbreds (RB, BR, RA, AR, BA, AB; letters indicate breed of sire and dam, respectively). Birth and weaning weight, hip height and body condition score at weaning (1 to 9) were analyzed with models that included breed group, year, dam age, dam winter nutritional regime (n=2), and calf sex as fixed effects. Calf age in days at weaning was included as a continuous variable. Sire within breed was a random term. Heterosis was significant for birth weight for A with R (5.7%, 1.68 ± 0.61 kg), A with B 9.8%, 2.98 ± 0.67 kg), and R with B (7.8%, 2.39 ± 0.61kg). Birth weight direct effects for A, B, and R were- 4.11± 0.94, 6.99 ± 1.02, and -2.88 ± 1.02 kg, respectively, and maternal effects were 1.57 ± 0.66, -5.32 ± 0.67, 3.75 ± 0.62 kg, respectively (P < 0.001). F1 calves (BA and BR) were 4.69 ± 0.99 kg and 5.95 ± 0.9 kg heavier than the respective reciprocal crosses (P< 0.001). Heterosis for weaning weight ranged from 11.6 ± 3.59 kg (5.6%, A with R) to 22.1 ± 4.02 kg (9.94%, A with B). Weaning weight direct effects were significant for B (13.08 ± 6.02 kg) and R (-21.62 ± 5.5 kg); maternal effects were significant for A (23.02 ± 3.86 kg) and B (16.02 ± 3.96kg). Heterosis for hip height was 1.44 ± 0.68, 1.98 ± 0.7, and 2.44 ± 0.77 cm, respectively, for R with A (1.3%), R with B (1.7%), and B with A (2.1%), Direct effects were significant for A and B (-5.53 ± 1.15 cm, 6.42 ± 1.16 cm respectively). Maternal effects on hip height were significant for A, B, and R (4.27 ± 0.73, 2.5 ± 0.76, and 1.77 ± 0.7 cm, respectively). Heterosis for body condition score was significant for B with R (3.3%, 0.19 ± 0.04) and for A with B (2.1%, 0.13 ± 0.05). Brahman maternal effects for body condition score (0.12 ± 0.07) were significant. Romosinuano germplasm may be best utilized as crosses, especially with Brahman, for early calf performace.
Technical Abstract: Typically the adaptation of beef cows that is required in the subtropics has been accomplished by using percentage Brahman breeding. They are well adapted for the stresses of the subtropical environment, but carcass merit of market animals has been questioned. A herd of Romosinuano (R), a Bos taurus, criollo breed native to Colombia has been developed at STARS, and were evaluated in a 3 breed diallel crossbreeding study with Angus (A; temperate Bos taurus) and Brahman (B; tropical Bos indicus). Calves (n=135) born in 2002 were straightbred AA, BB and RR, or crossbreds (RB,BR,RA,AR,BA,AB;letters indicate breed of sire and dam, respectively). Steer calves were weaned in late September and shipped 2025 km to El Reno, OK for growing and finishing, after grazing wheat pasture until May, 2003, they were finished on a conventional feedlot diet. Steers were serially slaughtered at 97,125 and 153 days on feed. Carcass information was collected after a 48-hr chill at 4° C. Calf age at weaning and days on feed were included as continuous variables. Sire within breed was a random term Back fat (BF) and yield grade (YG) increased (P< 0.10) over days on feed at an increasing rate for BA and at a decreasing (P< 0.10) rate in AA, BB, and RB. Marbling score increased (P< 0.10) linearly with days on feed more rapidly with AA and BB than with RR, while crossbreds were not different from RR. Direct effects for A, B, and R for carcass weight, BF, YG and marbling were 30.6**, and 193**,-99**, and -94**, respectively (*=P<0.05;**=P< 0.01). Heterosis (P<0.05) was observed among all combinations for carcass weight, and for A with B and B with R for BF and YG. Angus influence increased the percentage grading choice. Tropically adapted (R or B) were similar in number choice (~70%) when crossed with A.