|RILEY, DAVID - Former ARS Employee|
|Chase, Chadwick - Chad|
|COLEMAN, SAMUEL - Retired ARS Employee|
|OLSON, TIMOTHY - Retired Non ARS Employee|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/10/2014
Publication Date: 5/1/2014
Publication URL: http://handle.nal.usda.gov/10113/58746
Citation: Riley, D.G., Chase, C.C., Coleman, S.W., Olson, T.A. 2014. Evaluation of the Criollo breed Romosinuano as purebred and crossbred cows with Brahman and Angus in Florida. II. Maternal influence on calf traits, cow weight, and measures of maternal efficiency. Journal of Animal Science. 92(5):1911-1919.
Interpretive Summary: Heterosis or hybrid vigor is beneficial for the rapid genetic improvement of traits related to cow reproduction. Brahman-British crossbred cows exhibit larger heterosis for calving and weaning rate than for Bos taurus crosses. Knowledge of maternal heterosis, that is, that heterosis expressed as influence of crossbred cows on the weight traits of their calves, is beneficial in developing overall genetic strategies for improvement in the cow-calf phase of beef production. Production system flexibility would be enhanced if cows of other breed combinations provided adaptation and maternal heterosis that was similar to the levels of Brahman-Bos taurus cows. The Criollo breeds of the Americas are adapted to tropical conditions and have a reputation for excellent fertility when crossed with Brahman. The objectives of this research were to compare the Criollo breed Romosinuano as straightbred and crossbred cows with Angus and Brahman in subtropical Florida, and to estimate heterosis for size traits of their calves, their own weight, and maternal efficiency traits. Cows (n = 404) were born from 2002 to 2005 and calves (n = 1,254) from 2005 through 2011. Estimates of heterosis for weaning weight, body condition score, and average daily gain ranged from 1.3 to 13.2% for all pairs of breeds. Estimates of heterosis for birth weight (3.2 to 8.2%) and hip height (2.3%) were significant for Romosinuano-Angus and Brahman-Angus. Heterosis for cow weight was 65 kg for Brahman-Angus, and estimates for other breed pairs was approximately one-half that value. Heterosis for weaning weight/100 kg cow weight was 3.4 kg for Romosinuano-Angus. Heterosis for weaning weight/calving interval ranged from 0.08 to 0.12. Heterosis for weaning weight/cow exposed were 31.6, 36.9, and 59.1 kg for Romosinuano-Angus, Romosinuano-Brahman, and Brahman-Angus, respectively. Romosinuano crossbred cows displayed very acceptable maternal performance; however, Brahman-Angus crossbred cows had superior maternal performance.
Technical Abstract: The objectives of this work were to compare the Criollo breed Romosinuano as straightbred and crossbred cows with Angus and Brahman in subtropical Florida and to estimate heterosis for size traits of their calves, their own weight, and maternal efficiency traits. Cows (n = 404) were born from 2002 to 2005. After their first exposure to bulls as young cows, crossbred cows were bred to bulls of the third breed, and straightbred cows were bred in to bulls of the other 2 breeds. Calves were spring-born from 2005 through 2011. Evaluated calf (n = 1,254) traits included birth weight and weight, ADG, BCS, and hip height at weaning. Cow weight (n = 1,389) was recorded at weaning. Maternal efficiency traits evaluated included weaning weight per 100 kg cow weight, weaning weight per calving interval, and weaning weight per cow exposed to breeding (n = 1,442). Fixed effects and their interactions were investigated included sire and dam breed of cow, sire breed of calf, cow age, year, calf gender, and weaning age as a linear covariate (calf traits at weaning). Direct and maternal additive genetic effects were random in models for calf traits; only direct additive effects were modeled for cow traits. Cows sired by Angus bulls from outside the research herd had calves that were heavier at birth and weaning, and greater ADG, BCS, and hip height (P < 0.05). Estimates of heterosis for weaning weight, BCS, and ADG ranged from 1.3 to 13.2% for all pairs of breeds (P < 0.05). Estimates of heterosis for birth weight (3.2 to 8.2%) and hip height (2.3%) were significant for Romosinuano-Angus and Brahman-Angus. Heterosis for cow weight was 65 ± 8 kg for Brahman-Angus (P < 0.001), and estimates for other pairs of breeds were approximately one-half that value. Heterosis for weaning weight/100 kg cow weight was 3.4 ± 0.75 kg for Romosinuano-Angus. Heterosis estimates for weaning weight/calving interval (P < 0.001) ranged from 0.08 ± 0.01 to 0.12 ± 0.01. Heterosis for weaning weight/cow exposed were 31.6 ± 7.7, 36.9 ± 7.4, and 59.1 ± 7.5 kg for Romosinuano-Angus, Romosinuano-Brahman, and Brahman-Angus, respectively (P < 0.001). Most aspects of Romosinuano crossbred maternal performance were acceptable; maternal performance of Brahman-Angus cows excelled.