Relationship of some body measurements with the ultrasound measurements (rib eye area, rump fat thickness) in the Aubrac and Charolais fattening bulls

Abstract

Aims of the present study were to determine the difference between Aubrac and Charolais fattening bulls in the body measurements, in addition to calculate correlation among the body and ultrasonic measurements. The investigations were carried out on the fattening bulls of the two breeds with the age of 18.6 months (AUB, n=18, CH, n=8) in one fattening farm in Italy in 2007. The main body measurements of bulls (height at withers, HW; height at rump, HR; chest girth, CG; slanting body length, SBL) were taken, and ultrasonic measurements (rib eye area, REA, rump fat thickness, P8) were performed with Falco 100 (Pie Medical) equipment on the farm. The independent samples t-test was applied to prove the differences between the two groups in all tested traits. For describing the relationships among the body and ultrasonic measurements the method of analysis of simple correlation were used. The means of body measurement for HW, HR, CG, SBL in AUB and CH were 121.9 cm; 129.7 cm; 201.8 cm; 145.6 cm, and 125.2 cm, 132.2 cm, 202.0 cm, 157.0 cm, respectively. Significant difference only in SBL (-11.389, t: -5.392, df: 21.712, P=0.0001, α=0.05) was confirmed between AUB and CH. Similar REA value was experienced in the two breeds: AUB: 96.8 cm², CH: 94.8 cm², whereas the P8 value was more favourable in AUB compared to CH (-0.194 cm, t: 2.071, df: 24, P=0.049, α=0.05). As for the correlations, medium coefficients were calculated between body weight (BW) and HW in both groups (AUB, r=0.534, P<0.05, CH, r=0.558), as well as between BW and CG (r=0.665, P<0.01), plus between BW and REA (r=0.518, P<0.05) in AUB breed. However, a close relation was observed between BW and HR (r=0.832, P<0.01), moreover between P8 and HR (r=-0.742, P<0.05) in the CH group. By our results ultrasonic measurements are reasonable to be evaluated together with the body measurements in the practice.