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

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.