Ultrasonic estimates of fat thickness, C measurement and longissimus dorsi depth were assessed in 14 Rasa Aragonesa ewes with same body condition score. The ultrasonic estimates have been used for predicting tota1 carcass fat and muscle. The 76% of the variation in carcass lumbar fat thickness was accounted for by variation in lumbar fat thickness assessed by
ultrasonic machine, whereas 53% of the variation in C measurement was accounted. Nevertheless only 5% of variation in m.
Longissimus dorsi depth was accounted for by variation in this measurement assessed by ultrasonics. The inclusion of cold carcass
weight as an independent variable in a multiple regression with lumbar fat thickness assessed by ultrasonics and the same
measurement obtained on carcass improve the precision of total carcass fat and muscle predictions (r=81 and 91%)
