USE OF ULTRASOUND FOR THE PREDICTION OF CARCASS CHARACTERISTICS IN ALPINE GOATS

Area and maximum depth of the longissimus muscle were measured using r eal-time ultrasound on 25 male Alpine goat kids. To our knowledge, thi s is the first report of use of real-time ultrasound to estimate carca ss quality in goats. Ultrasonic measurements were taken: (A) between t he 12th and 13th ribs and (B) at the first lumbar vertebra. Live weigh t, condition score, circumference of the widest part of the hind leg, length of the hind leg from the hip, heart girth, body length from sho ulder to tail and length of the hind leg from hip to hock were also re corded. Kids were slaughtered 5 d after ultrasound measurements were t aken. From carcass measurements, area of the longissimus muscle at bot h sites A and B averaged 5.6 cm(2), and ranged from 4 to 8 cm(2) at si te A and from 3.6 to 7.6 cm at site B. At site A, the 12th and 13th ri bs were very close together and it was difficult to obtain a distortio n-free ultrasound image. Ultrasonograms at site B were free from rib-c aused distortion, but this site was more difficult to locate repeatabl y. Despite these complications, the accuracy of measurement of longiss imus area did not differ (P>0.05) between the two sites. Maximum longi ssimus depth was more accurately measured at site A than at site B (P< 0.05). Regression equations and residual standard deviation (RSD) valu es indicated that longissimus area at site A was the indicator of carc ass muscling most accurately predicted by ultrasound and body dimensio n measurements (R(2)=0.81, RSD=3.6). Longissimus area could not be pre dicted from body dimensions without ultrasound data at site B, while f or site A, length of the hind leg (P<0.05) was the only predictor (R(2 )=0.22, RSD=7.2). Therefore, the use of real-time ultrasound would imp rove the selection of meat goats for improved muscling.