The objective this study was to evaluate the correlation between traits obtained real time ultrasound and those obtained in the carcass of feedlot finished lambs. Forty eight no castrated, woolless crossbred Santa Inês lambs with initial 20.0 kg LW and 103 days old. The measures obtained by ultrasound in real time were determined using by Aloka 500SSD ultrasound machine, equipped with 3.5-MHz linear transducer. Before the slaughter, using the real time ultrasound, were measured between at 12th - 13th ribs of the lambs the subcutaneous fat thickness (USFT) and longissimus muscle area (ULMA), slaughter body weight (SBW) and the corporal condition (CC). After the slaughter were obtained the hot carcass weight (HCW), internal fat percentage (IFP), hot carcass dressing (HCD), carcass subcutaneous fat thickness (CSFT) and the longissimus muscle area (CLMA). There was correlation between traits measured by real time ultrasound and those obtained in the carcass, except for SBW vs CSFT (0.22) and HCW vs CSFT (0.33). Highly correlation was observed between longissimus muscle area obtained by real time ultrasound and the same measure determined in the carcass. The measures of USFT and CSFT showed also significant correlation. The use of the ultrasound was an efficient method to estimate, in real time, the loin eye area and fat thickness of the lambs.
body score; fat thickness; loin eye area; percentage of internal fat; sheep
