Influence of dietary calcium and phosphorus content in a fixed ratio on growth and development in Great Danes.
OBJECTIVE
To study the musculoskeletal development of Great Dane puppies fed various dietary concentrations of calcium (Ca) and phosphorus (P) in fixed ratio by use of dual energy x-ray absorptiometry (DEXA), determination of serum insulin-like growth factor 1 and parathyroid hormone concentrations, radiography, and blood chemistry analysis results.


METHODS
32 purebred Great Dane puppies from 4 litters.


METHODS
At weaning, puppies were assigned randomly to 1 of 3 diets. Blood was collected for biochemical analyses and hormone assays, and radiography and DEXA were performed through 18 months of age. Changes in body weight, bone mineral content, fat tissue weight, lean mass, result of serum biochemical analyses, hormonal concentrations, and radius lengths were analyzed through 18 months of age.


RESULTS
Bone mineral content of puppies correlated positively with Ca and P content of the diets fed. Significant differences between groups in bone mineral content, lean mass, and body fat were apparent early. The disparity among groups increased until 6 months of age and then declined until body composition was no longer different at 12 months of age. Accretion rates for skeletal mineral content, fat, and lean tissue differed from each other and by diet group.


CONCLUSIONS
Ca and P concentrations in the diet of young Great Dane puppies are rapidly reflected in the bone mineral content of the puppies until 5 to 6 months of age, after which hormonal regulation adjusts absorption and excretion of these minerals. Appropriate Ca and P concentrations in diets are important in young puppies < 6 months of age.
Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, AL 36849, USA.
Susan D
SD
Lauten
Nancy R
NR
Cox
William R
WR
Brawner
Susan A
SA
Goodman
John T
JT
Hathcock
Ronald D
RD
Montgomery
Steven A
SA
Kincaid
Nancy E
NE
Morrison
Joseph S
JS
Spano
Allan J
AJ
Lepine
Gregory A
GA
Reinhart
Henry J
HJ
Baker
D015502:Absorptiometry, Photon / Q000662:veterinary; D000821:Animal Feed; D000818:Animals; D001774:Blood Chemical Analysis / Q000662:veterinary; D015519:Bone Density / Q000502:physiology; D002136:Calcium, Dietary / Q000378:metabolism / Q000494:pharmacology*; D004285:Dogs / Q000254:growth & development* / Q000378:metabolism; D004435:Eating; D005260:Female; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D016226:Phosphorus, Dietary / Q000378:metabolism / Q000494:pharmacology*; D011884:Radius / Q000000981:diagnostic imaging / Q000502:physiology; D011897:Random Allocation
D002136:Calcium, Dietary; D010281:Parathyroid Hormone; D016226:Phosphorus, Dietary; D007334:Insulin-Like Growth Factor I