Selection of performance-tested young bulls and indirect responses in commercial beef cattle herds on pasture and in feedlots

Abstract

BackgroundCentral testing is used to select young bulls which are likely to contribute to increased net income of the commercial beef cattle herd. We present genetic parameters for growth and reproductive traits on performance-tested young bulls and commercial animals that are raised on pasture and in feedlots.MethodsRecords on young bulls and heifers in performance tests or commercial herds were used. Genetic parameters for growth and reproductive traits were estimated. Correlated responses for commercial animals when selection was applied on performance-tested young bulls were computed.ResultsThe 90% highest posterior density (HPD90) intervals for heritabilities of final weight (FW), average daily gain (ADG) and scrotal circumference (SC) ranged from 0.41 to 0.49, 0.23 to 0.30 and 0.47 to 0.57, respectively, for performance-tested young bulls on pasture, from 0.45 to 0.60, 0.20 to 0.32 and 0.56 to 0.70, respectively, for performance-tested young bulls in feedlots, from 0.29 to 0.33, 0.14 to 0.18 and 0.35 to 0.45, respectively, for commercial animals on pasture, and from 0.24 to 0.44, 0.13 to 0.24 and 0.35 to 0.57 respectively, for commercial animals in feedlots. The HPD90 intervals for genetic correlations of FW, ADG and SC in performance-tested young bulls on pasture (feedlots) with FW, ADG and SC in commercial animals on pasture (feedlots) ranged from 0.86 to 0.96 (0.83 to 0.94), 0.78 to 0.90 (0.40 to 0.79) and from 0.92 to 0.97 (0.50 to 0.83), respectively. Age at first calving was genetically related to ADG (HPD90 interval = −0.48 to −0.06) and SC (HPD90 interval = −0.41 to −0.05) for performance-tested young bulls on pasture, however it was not related to ADG (HPD90 interval = −0.29 to 0.10) and SC (HPD90 interval = −0.35 to 0.13) for performance-tested young bulls in feedlots.ConclusionsHeritabilities for growth and SC are higher for performance-tested young bulls than for commercial animals. Evaluating and selecting for increased growth and SC on performance-tested young bulls is efficient to improve growth, SC and age at first calving in commercial animals. Evaluating and selecting performance-tested young bulls is more efficient for young bulls on pasture than in feedlots.

Across-sex genomic-assisted genetic correlations for sex-influenced traits in Brahman cattle

“…Similar results are found in the literature i.e. Van Vleck and Cundiff [30] reported an r g between homologous growth traits in males and females higher than 0.85, van der Heide et al [8] found an r g between male and female post-weaning productive traits that ranged from 0.68 to 0.84, while Raidan et al [31] obtained an r g of 0.96 for final weight and 0.74 for average daily gain in male and female Nellore cattle raised on pasture. A genetic correlation lower than 1 between male and female traits could be due to limitations of the experimental design and size, or to differences in the performance testing environments between females and males (for instance, differences at age of measurement of EMA in this study), or differences in the genetic bases and/or selection objectives, and means and standard deviations in each sex [32].…”

Oxidative stress associated with proteomic and fatty acid profiles of sperm from Nellore bulls at rest

“…Selecting breeding bulls with proven fertility is essential to ensure sustainability and economic returns to cattle breeding [9]. Due to the complex nature of the events involved with spermatozoa fertilizing capacity, several situations or conditions influence the competence and integrity of sperm cells, resulting in reproductive failure and economic losses in beef cattle [10][11][12].…”

Relationships between Biomarkers of Oxidative Stress in Seminal Plasma and Sperm Motility in Bulls before and after Cryopreservation

“…Central testing is used to select young bulls that could produce the next generation of bulls in order to increase the net income of commercial cattle herds [ 1 ]. In the bovine artificial insemination (AI) industry, semen from young and genomic bulls is collected and marketed globally.…”