The objective of this study was to estimate genetic correlations between calving difficulty score and carcass traits in Charolais and Hereford cattle, treating first and later parity calvings as different traits. Genetic correlations between birth weight and carcass traits were also estimated. Field data on 59,182 Charolais and 27,051 Hereford calvings, and carcass traits of 5,260 Charolais and...

A new carcass EPD has been developed for the American Angus Association’s National Carcass Evaluation Program. A percentage of retail product EPD combines the traditional carcass traits (hot carcass weight, fat thickness, ribeye area and KPH) into a composite EPD. Although the heritabilitty for this trait (.25) is not the highest for the carcass traits, it is high enough for breeders to make si...

The use of Longissimus thoracis et lumborum muscle (LM) volume measured in vivo by real-time ultrasonography (RTU) to estimate carcass composition was evaluated in 47 female sheep. Animals were scanned over six sites (7th, 9th, 11th and 13th thoracic vertebrae and 2nd and 4th lumbar vertebrae). After slaughter carcass weight (CW) and composition by dissection were determined. RTU volume measure...

Live animal and carcass data were collected from market barrows and gilts (n = 120) slaughtered at a regional commercial slaughter facility to develop and test prediction equations to estimate carcass composition from live animal and carcass ultrasonic measurements. Data from 60 animals were used to develop these equations. Best results were obtained in predicting weight and percentage of bonel...

Fifty merino wethers (liveweight range from 44 to 81kg, average of 58.6kg) were lot fed for 42d and scanned through a dual X-ray absorptiometry (DXA) as both a live animal and whole carcass (carcass weight range from 15 to 32kg, average of 22.9kg) producing measures of total tissue, lean, fat and bone content. The carcasses were subsequently boned out into saleable cuts and the weights and yiel...

To study the allometric growth of body and carcass traits, twelve new born Karadi lambs were docked within 3 days their birth using rubber-rings, left with mothers till weaning (2.5 months). Another 12 weaned obtained from local market intact. Following an adaptation period a week, intact average initial weight 16.83±1.522 19.92± 0.748kg, respectively randomly divided into three equal groups to...

The most widely used system to predict percentage of retail product from the four primal cuts of beef is USDA yield grade. The purpose of this study was to determine whether routine ultrasound measurements and additional rump measurements could be used in place of the carcass measurements used in the USDA yield grade equation to more accurately predict the percentage of saleable product from th...

In genetic improvement programmes for beef cattle, the effect of selecting for a given trait or index on other economically important traits, or their predictors, must be quantified to ensure no deleterious consequential effects go unnoticed. The objective was to compare live animal measurements, carcass composition and plasma hormone and metabolite concentrations of male progeny of sires selec...

Use of lamb BW or chilled carcass weights (CCW), live-animal ultrasound or direct carcass measurements of backfat thickness (BF; mm) and LM area (LMA; cm2), and carcass body wall thickness (BWall; mm) to predict carcass yield and value was evaluated using 512 crossbred lambs produced over 3 yr by mating Columbia, U.S. Meat Animal Research Center Composite, Suffolk, and Texel rams to adult Rambo...