Evaluation of electronic technology to assess lamb carcass composition.

Abstract

Accurate price signals are essential for producers of American lamb to ensure production of uniformly lean animals. Development of carcass merit-pricing systems will require the use of objective technology for assessing carcass composition or lean distribution. The objective of this study was to evaluate electronic technologies for accurate determination of lamb carcass composition. Lambs (n = 106) were selected as a representation of U.S. market lambs that transcended geographic location, sex, breed, carcass weight, yield grade, and production system. The independent variables used to predict lamb composition varied with the technology. The electronic technologies tested included realtime ultrasound, optical reflectance probe, bioelectrical impedance analysis, and electromagnetic scanning (TOBEC). All technologies, except realtime ultrasound, were tested on warm (prerigor) carcasses and repeated after a 24-h chill. Longitudinal ultrasonic scans of fat and muscle tissue depth and grading probe fat depths were marginal predictors of proportional carcass yield. The TOBEC measurements often accounted for more variability associated with kilograms of dissected lean and percentage of carcass lean than did carcass weight. Equations from TOBEC measurements were the most accurate predictors of weight and percentage of dissected and fat-free lean. Bioelectrical impedance measurements of resistance and reactance combined with carcass weight were also good predictors of carcass composition. Prediction of carcass lean distribution by measures of TOBEC were the most accurate for prediction of leg lean. The implications of usefulness of these technologies will depend on the commitment of the U. S. sheep industry in development of a lamb price discovery system based on carcass composition.

Prediction of the chemical composition of mutton with near infrared reflectance spectroscopy

“…and coefficients of variation (C.V.) of the calibration and validation sets for the chemical composition constituents are shown in Table 1 and Table 2, respectively. The variation in the chemical composition of the samples used seemed to cover the whole spectrum found for mutton reported in the literature for mutton (Berg et al, 1997, Hopkins et al, 1992and Teixeira et al, 1996.…”

Características de carcaça, componentes não-carcaça e composição tecidual e química da 12ª costela de cordeiros Santa Inês terminados em pasto com três gramíneas no período seco

“…(1992) e Berg et al (1997) e confirmando a importância da ultra-sonografia no acompanhamento da avaliação da massa muscular da carcaça. A avaliação por ultra-som apresentou subestimativa de aproximadamente 2 cm 2 .…”

“…Outra forma de se realizar essas observações é o uso da ultra-sonografia, que possibilita boa estimativa da massa muscular e auxilia na determinação da melhor época de abate do animal ainda vivo (McLaren et al, 1991;Hougthon & Turlingthon, 1992;Berg et al, 1997).…”

Estimação da composição química do corpo vazio de animais Nelore e Caracu a partir das composições química e física do corte da 9ª-10ª-11ª costelas

“…Alguns métodos já foram desenvolvidos para estimação indireta da composição corporal, entre eles, a gravidade específica (Alhassan et al, 1975), a composição de cortes (Alhassan et al, 1975), a composição da seção da 9 a -10 a -11 a costelas (Hankins & Howe, 1946), a ultra-sonografia (Berg et al, 1997), as provas de refletância óptica (Berg et al, 1997) e outros métodos eletrônicos. Em razão das várias limitações operacionais e financeiras, os métodos mais utilizados são o da gravidade específica e o da composição do corte da 9 a -10 a -11 a costelas.…”