Abstract:
Animal Production in Australia THE ACCURACY OF THE TOLAND PROBE IN MEASURING HOT FAT DEPTH S.K. ANDERSON* and T.G. TRUSCOTT* In Victoria, the Toland probe (Toland 1978) is used to measure hot carcase fat depth in manual beef carcase classification. This paper describes some aspects of accuracy and precision in its operation. Data were collected in three studies in 1979, 1980 and 1981 using a variety of breeds which varied in carcase weight (128-414 kg) and fat depth (l-19 mm). Prior to measurement of fat depth, the measuring position (between the 12th and 13th ribs over the 1. dorsi at about 0.75 its width) was marked on each side of the carcase. While correlations were high (0.91, 0.91 and 0.96) and RSD's low and 0.97 mm) between hot fat depth measurements on undamaged left and made by an experienced operator (TPl) in each year (n = 63, 50, 140), co-efficients of residual variation were still quite large (17.7, 16.2 (1.18, 0.99 right sides respectively, and 14.9%). Linear relationships between operators (TPl, TP2 - experienced; TP3 inexperienced) had regression co-efficients significantly different from 1.00 (Table 1) as did the relationships between TPl and a fourth operator (CM) using the cut and measure technique (Table 1). TP2 and CM tended to have higher measurements than TPl above 4.4 and 3.9 mm respectively, but TP3 had higher measurements than TPl on all carcases. TABLE 1 Relationships between operators' hot fat depths (H-mm) taken on the left half carcase and cold fat depth (CFD-~-t-m) taken on the right half carcase * PcO.05 that b different to 1.00 In the 1981 study, TPl hot fat depths were more closely related to cold measurements on opposite half carcases than were CM fat depths (Table 1). It is concluded that experienced Toland probe operators can have a high degree of repeatability in measuring hot fat depth but significant variation between operators is likely to exist. The 1981 study suggests that the Toland probe may be more accurate than cut and measure, but further trials are required to eliminate the possibility of specific operator effects in our data. TOLAND, P. (1978). Provisional patent PD No. 5618, Aust. Patents Act 1952-1969. * Department of Agriculture, GPO Box 4041, Melbourne, Vic. 3001. 607
