An exhaustive review of estimates of heritability (h) for a broad spectrum of beef production traits published in the scientific literature from 1945 to 1991 was conducted by Koots et al. (1994), but their review did not include other important carcass traits (e.g., kidney, pelvic, and heart fat percentage, yield grade, fat weight) and due to the purpose of their study, individual estimates of ...

The objective of this study was to evaluate the genetic response for a divergent selection experiment on intramuscular fat (IMF) content and to estimate the correlated response in carcass and meat quality traits. Data from two generation of selection were used in this study. The base population was composed of 13 males and 83 females. High (H) and Low (L) lines had 8 males and approximately 40 ...

Objectives of this study were to determine the influence of trenbolone acetate (TBA) and estradiol (E2) in a combined implant on feedlot performance, carcass characteristics, and carcass composition in finishing steers. Sixty-four large-framed (394.1 kg) crossbred steers were randomly assigned to one of four pens. Subsequently, pens were randomly assigned to one of two treatments, implanted (12...

A joint growth-carcass model using random regression was used to estimate the (co)variance components of beef cattle body weights and carcass quality traits and correlations between them. During a four-year period (1994-1997) of the Australian "southern crossbreeding project", mature Hereford cows (N = 581) were mated to 97 sires of Jersey, Wagyu, Angus, Hereford, South Devon, Limousin, and Bel...

With the adoption of visual instrument grading, the calculated yield grade can be used for payment to cattle producers selling on grid pricing systems. The USDA beef carcass grading standards include a relationship between required LM area (LMA) and HCW that is an important component of the final yield grade. As noted on a USDA yield grade LMA grid, a 272-kg (600-lb) carcass requires a 71-cm(2)...

Carcass evaluation has a relatively long history in the animal and meat science scientific literature and one of the first studies to cover the composition of farm animals was reported by Lawes and Gilbert (1860) almost 130 years ago. These workers completed a large number of chemical analyses and found a relationship between fat and maturity (age and weight); a finding that has been repeated b...

In each of two experiments, 70 crossbred steers were blocked by BW and assigned to initial slaughter groups or to treatments in a 2 x 2 design. In Exp. 1, treatments were 168 d of photoperiod (8 h of light [L]:16 h of dark [D] or 16L:8D) and plane of nutrition (high energy [HPN] or low energy [LPN]). On d -22, 67 and 155, blood was sampled every 20 min for 8 h. Relative to LPN, HPN increased (P...

Spanish x Boer (n = 16) and Spanish x Kiko (n = 18) wethers (7 mo) and bucklings (5 mo) were harvested under USDA inspection to evaluate the effect of dam breed on carcass traits of crossbred kids. Boer and Kiko dams, respectively, originated from five and seven seedstock farms. Each dam was purebred or fullblood (93.75 to 100%). Traits of interest included live weight and conformation score, c...

The objective of this study was to quantify the genetic variation in carcass cuts predicted using digital image analysis in commercial cross-bred cattle. The data set comprised 38,404 steers and 14,318 heifers from commercial Irish herds. The traits investigated included the weights of lower value cuts (LVC), medium value cuts (MVC), high value cuts (HVC), very high value cuts (VHVC) and total ...