Sample size and prediction of weight and yield of individual cuts from Braford steers pistol hindquarters

Abstract

Two hundred seventeen grass-finished Braford steers were assessed by ultrasonic scanning and subsequently harvested with their pistol hindquarters fabricated into boneless wholesale cuts. The Longissimus thoracis muscle area and subcutaneous fat depths were measured. The objectives of this study were: 1) to develop prediction equations for weights of the pistol hindquarter and high-value commercial cuts, and 2) to estimate sample size needed for experiments comparing pistol hindquarter retail product weight using either physically or ultrasonically measured carcass traits. Carcass measurements explained 44 % to 94 % of the variation in weights of individual cuts, whereas, measurements that were made using ultrasound explained 42 % to 90 % of the variation in the weights. Models used to predict the weight of pistol hindquarter retail product with carcass measures and ultrasound measures showed high coefficient of determination (R 2 = 0.92 and 0.97, respectively). Whether based on carcass or ultrasound measures, models used to estimate weight percentage of fat trimmed from the pistol hindquarter had lack of fit. In general, models for individual cuts weights that used traits measured with ultrasound as independent variables approached the accuracy of models using carcass traits. Thus, only slightly greater samples sizes were required to have equivalent power to detect differences in retail product weights using ultrasound measures. For experiments of equivalent power, differences in the number of animals required may be offset by avoiding costs for slaughter and fabrication.

Predicting the carcass characteristics of Morada Nova lambs using biometric measurements

“…The measurements in the live animal did not result in substantial increases in R² but led to reducing the lack of fit (Cp~p) and reduced residual variance (Cardoso et al, 2020). Hernandez-Espinoza et al (2012) reported that carcass yield is associated with withers height.…”

Cattle stratified on genetic merit segregate on carcass characteristics, but there is scope for improvement1

“… Pabiou et al (2011) proposed such a strategy using video image analysis of cattle carcasses and reported a correlation of up to 0.96 between groups of primal carcass yields (i.e., very high-value cuts, high-value cuts, medium value cuts, and low value cuts) and the respective yield predictions from video image analyses. Using a population of 217 commercial Bradford Brazilian steers, Cardoso et al (2019) documented the ability of ultrasound measures of longissimus thoracic muscle area and/or subcutaneous fat thickness on live animals immediately prior to slaughter to predict pistol hindquarter cut weights. Other technologies to predict carcass characteristics also exist, each with differing levels of prediction accuracy and cost ( Scholz et al, 2015 ).…”

Morphometric measurements of calves of beef cattle from different genetic groups up to one year of age

“…Body measurements of BL, and FG and TG in cattle are important, since these measurements correlate positively with carcasses of greater size, better conformation (Pacheco et al, 2014), and greater retail cut yield (Pascoal et al, 2010;Cardoso et al, 2020). The selection of animals with greater muscling adds value at slaughter, as their carcasses have greater dressing percentages and yields of retail cuts (Cardoso et al, 2020).…”