Untersuchungen zur Anwendbarkeit der Dualenergie-Röntgenabsorptiometrie (DXA) für die Messung der Ganzkörperzusammensetzung bei zwei Putengenotypen

摘要

The objective of this study was to evaluate the measurement of whole body composition by dual-energy X-ray absorptiometry (DXA) in turkeys (post mortem). In total, 130 turkeys (1.3 – 24.1 kg) of two genotypes BUT Big6 and Kelly Bronze were scanned at 4 different ages by using DXA with a LUNAR DPX-IQ densitometer. Whole body scans were performed and analyzed twice using Pediatrie Small (Reference Mode) for all animals. Additionally, Pediatric Medium, Pediatric Large, Small Animal Medium, or Small Animal Small modes were used on a smaller number of animals. DXA measurements provided readings of fat mass, lean mass, bone mineral mass, and bone mineral density. The turkeys were frozen (-18 °C) and analyzed in a plastic bag. The body weight of Big6 (15.7 kg) in week 18 is already similar to the body weight of Kelly Bronze (16.3 kg) four (4) weeks later. After week 18, the DXA FAT (%) values were smaller (week 18: 12.6; week 24: 7.7 %) but the values for DXA LEAN (%) were higher (84.8 / 89.7 %) in Big6 than in Kelly Bronze (13.3 / 11.5 or 84.4 / 85.9 % respectively).The body weight can be predicted with a high precision (R² = 1; RMSE = 21 in g) and a high accuracy (R² = 0,996; RMSE = 351 in g) by DXA. These results indicate a good suitability of DXA to estimate the carcass composition of turkeys in vivo. But the results should be validated by chemical analysis or dissection.