Relação entre medidas de ultrassom e grau de acabamento de carcaças bovinas

Abstract

The purpose of this paper is to assess the applicability of ultrasound to predict the variables that interfere in the composition of the carcass of young bovines. A correlation between the measures obtained from the living animals and the characteristics of the carcass was carried out to verify the potential of the ultrasound in the prediction of the composition of the carcass of beef cattle; this aims at providing information for the selection and the handling of the composition and characteristics of the living animal without having to resort to slaughter. This body of research was conducted using data obtained from commercial animals at Marfrig slaughterhouse in the municipality of Bagé, State of Rio Grande do Sul. 126 castrated Hereford and Bradford specimens were used with an average age of 2 years old, and finalizing sizing measures of 2, 3 and 4. The ultrasound weighing and measuring were carried out 24 hours prior to slaughter and after a 12 hour fast. In order to conduct the ultrasound, the area between the 12th and 13th left ribs was cleaned. Immediately after that, vegetal oil was used on the animal‟s back to perfectly attach the transductor to the animal‟s body, therefore making the acoustic contact possible. The statistical analyses were carried out using the software R and the equations to estimate the stage of finishing were determined through logistical regression using the level of finishing as dependent variable and the measures taken via ultrasound, such as EG, AOL and P8, as independent variables. According to the results obtained in this work, it can be ascertained that the thickness of sub-skin fat (EG) and the thickness of the fat layer in the „picanha‟ beef cut - top sirloin - (P8) have influence over the finishing. Regarding the area of the rib eye (AOL), there was no influence over the finishing, thus, it was not significant.