Use of ultrasound to predict body composition changes in steers at 100 and 65 days before slaughter

Abstract

Steers from research crossbreeding projects (n = 406) were serially scanned using real-time ultrasound at 35-d intervals from reimplant time until slaughter. Cattle were evaluated for rump fat depth, longissimus muscle area (ULMA), 12th-rib fat thickness (UFAT), and percentage of intramuscular fat (IMF) to determine the ability of ultrasound to predict carcass composition at extended periods before slaughter. Additional background information on the cattle, such as live weight, ADG, breed of sire, breed of dam, implant, and frame score was also used. Carcass data were collected by trained personnel at "chain speed," and samples of the 12th-rib LM were taken for ether extract analysis. Simple correlation coefficients showed positive relationships (P < 0.01) between ultrasound measures taken less than 7 d before slaughter and carcass measures: ULMA and carcass LM area (CLMA, r = 0.66); UFAT and carcass 12th-rib fat thickness (CFAT, r = 0.74); and IMF and carcass numeric marbling score (r = 0.61). The same correlation coefficients for ultrasound measures taken 96 to 105 d before slaughter and carcass values (P < 0.01) were 0.52, 0.58, and 0.63, respectively. Steers were divided into source-verified and nonsource-verified groups based on the level of background information for each individual. Regression equations were developed for the carcass measurements; 46% of the variation could be explained for CLMA and 44% of CFAT at reimplant time, 46% of the variation in quality grade and 42% of the variation in yield grade could be explained. Significant predictors of quality grade were IMF (P < 0.001), natural log of 12th-rib fat thickness (LUFAT, P < 0.001), and ADG (P < 0.01), whereas LUFAT (P < 0.001), ULMA (P < 0.01), live weight (P < 0.001), hip height (P < 0.001), and frame score (P < 0.001) were significant predictors of yield grade. Regressions using ultrasound data taken 61 to 69 d before slaughter showed increasing R2. Live ultrasound measures at reimplant time are a viable tool for making decisions regarding future carcass composition.

Real-time ultrasound (RTU) imaging methods for quality control of meats

“…This approach for beef cattle was shown to be more accurate than simple visual appraisal (Delehant et al ., 1996). Sorting meat animals into uniform groups based on frame size, SFD and LMA can help to obtain carcasses with uniform slaughter weight and consistent composition, which can then be sold at the optimal time (Houghton and Turlington, 1992;Wall et al ., 2004;Rimal et al ., 2006). When cattle have an average initial SFD of more than 3 mm, ultrasound is useful in projecting the number of days required to reach a target SFD level, which allows animals to be clustered into groups for more effective marketing (Brethour, 2000).…”

“…Several studies have been carried out to analyse the efficacy of ultrasound as a predictor of carcass composition prior to slaughtering in beef cattle (Perkins et al ., 1992b;Smith et al ., 1992;Delehant et al ., 1996;Ragland et al ., 1997;Griffin et al ., 1999;Wall et al ., 2004) and in swine (McLaren et al ., 1989;Terry et al ., 1989;Gresham et al ., 1992Gresham et al ., , 1994Ragland et al ., 1997;Newcom et al ., 2002). Optimum composition means the highest lean meat proportion, and optimum organoleptic properties.…”

“…The methodology used to predict carcass composition should be accurate, fast and automated, and the first step in developing these prediction models is to achieve accurate measurement of the SFD and LMA, since these are the most frequently used predictors of carcass composition and quality (Perkins et al ., 1992b;Delehant et al ., 1996;Griffin et al ., 1999;Hassen et al ., 1999a;Suguisawa et al ., 2003;Wall et al ., 2004), and are the main price drivers for the value-based marketing system used by the meat industry. The use of RTU to measure both SFD and LMA in live animals has been well documented for both swine and beef cattle (e.g., Houghton and Turlington, 1992), and several studies have shown that it is an accurate method if the images are taken and interpreted by a trained technician (McLaren et al ., 1991;Perkins et al ., 1992b;Herring et al ., 1994;Hassen et al ., 1998).…”

The Variability of Growth Hormone Gene Associated with Ultrasound Imaging of Longissimus dorsi Muscle and Perirenal Fat in Rabbits

“…Ultrasonography is one of the most widely used techniques for in vivo prediction of carcass in swine, sheep and cattle (Moloney et al, 2002;Schroder & Staufenbiel, 2006;McEvoy et al, 2007). Some reports have also shown the suitability of this technique for the evaluation of body composition in rabbits (Pascual et al, 200;Cardinali et al, 2008), estimated of Longissimus muscle in sheep (Sahin et al, 2008;Esquivelzeta et al, 2012), cattle (Wall et al, 2004;Yokoo et al, 2008), pig (Micklander et al, 2005). Taking imaging with ultrasound does not interfere of livestock, low cost and useful method to evaluate subcutaneous and visceral adipose tissue in anatomy and different metabolic conditions (Stouffer, 2004).…”

Relação entre medidas ultrassônicas e da carcaça de bubalinos Murrah abatidos em diferentes períodos de confinamento

“…As medidas da espessura de gordura subcutânea do dorso foram numericamente inferiores àquelas realizadas na garupa em todos os períodos de confinamento. Esses resultados foram semelhantes aos encontrados com Wall et al (2004), que observaram em bovinos de corte que a deposição de gordura ocorre primeiramente na região do traseiro e depois na região lombar.…”