Studies on the development of the claws in new born calves of different breeds and crossbreds using Dual Energy X-Ray Absorptiometry (DXA)

Abstract

This study evaluated claw development in 199 calves of different genetic background during the first 70 days of life. Dual Energy X-Ray Absorptiometry (DXA) was found to be a useful tool for this purpose. By the means of DXA, in humans as in animals, body constitution and composition can be examined in vivo. Thus, the whole body or body regions can be analyzed for the content of fat tissue, lean tissue, bone mineral content and bone mineral density. Large differences in claw parameters were observed, depending on the position of the claws, sex and breed, including interaction effects between gender and breeds. In all four pairs of claws, the medial claws had significantly higher contents of bone mineral than the lateral claws. All fore claws had a higher density than hind claws. Male calves showed significantly higher values than females in all measured parameters. Comparing breeds and crossbreds, pure German Holsteins had the lowest values in all parameters with exception of the R-value. Within breeds/crossbreds and gender various interactions could be found. Calves of first lactation cows had lower values than calves of elder cows. Calves with a small birth weight and calves originating of a multiple birth had significantly lower values of the scanned parameters than calves with higher birth weight or monoparous calves.

Age Classes and Sex Differences in the Skull of the Mediterranean Monk Seal, Monachus monachus (Hermann, 1779). A study Based on Bone Shape and Density

“…Considering that deposition of the bone matrix is a characteristic of vertebrate growth, it was postulated that a higher bone density value of certain skull features should be observed in older skulls. Deposition of bone matrix is indeed a dynamic process that continues through the life span of mammals as attested by various studies on bone growth and mineralization processes inferred through the bone mineral density (BMD) measurements of various domestic mammal species (Martin et al,1981; Munday et al,1994; Lauten et al,2000,2001,2002; Mitchell et al,2001; Nüske et al,2002; Zotti et al,2004; Ekici et al,2005). These studies have shown that body weight is the most important intra and interspecific factor directly affecting bone mineral content and density.…”

Exceptional bone density DXA values of the rostrum of a deep-diving marine mammal: a new technical insight in the adaptation of bone to aquatic life

“…Although the rat is the most frequently used mammal in DXA-based investigations, the BMD of several species of larger-sized nonhuman mammals has already been reported [1]. Studies on a single specific bone or total body BMD have been performed on nonhuman primates [2,3], sheep [4], bovine calves [5,6], horses [7], pigs [8], dogs [9,10], cats [11], and striped [12] and bottlenose dolphins [13]. All BMD values (expressed as g/cm 2 ) obtained from the species listed above ranged between 0.463 (canine III metacarpal bone) and 2.12 (pig skull).…”

Untersuchungen zur Körperzusammensetzung und zum Wachstum von Kälbern unterschiedlicher genetischer Herkunft mittels Dualenergie–Röntgenabsorptiometrie (DXA)

“…Intention dieser Arbeit ist es, im Rahmen eines Kreuzungsversuches zwischen den Rassen Deutsches Fleckvieh und Deutsche Holsteins das DXA Verfahren erstmals bei Kälbern in vivo einzusetzen, um damit Erkenntnisse über deren Wachstum und Kör-perzusammensetzung zu erlangen. Diese Studie ist Teil eines Projektes, das sich außerdem mit der Untersuchung des Klauenwachstums bei neugeborenen Kälbern befasst (NÜSKE et al, 2002) sowie in einer noch andauernden Studie Referenzuntersuchungen zwischen DXA-Analyse und Totalzerlegung (MUSICK, persönliche Mitteilung) befasst. Die DXA-Untersuchung zählt zu den häufig in der Humanmedizin angewendeten Techniken zur Ermittlung der Körperzusammensetzung und zeigt eine sehr große Prä-zision und Genauigkeit.…”