| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
* Department of Animal Science, Cornell University, Ithaca, NY 14850
Bovine Functional Genomics Lab, USDA-ARS, Beltsville, MD 20705
2 Corresponding author: mev1{at}cornell.edu
Prior to puberty, elevated nutrient intake has been shown to negatively affect prepubertal mammary development in the heifer. The objective of this study was to evaluate the effects of increased nutrient intake on mammary development in Holstein heifers at multiple body weights from birth through puberty. Specifically, this study evaluated the effects of nutrient intake and body weight at harvest on 1) total weight and DNA content of the parenchyma (PAR) and mammary fat pad (MFP) and 2) PAR and MFP composition. Starting at 45 kg of body weight, heifers (n = 78) were assigned to either a restricted (R) or elevated (E) level of nutrient intake supporting 650 (R) or 950 (E) g/d of body weight gain. Heifers were harvested at 50-kg increments from 100 to 350 kg of body weight. Mammary fat pad weight and DNA content were greater in E- than in R-heifers. Additionally, E-heifers had a greater fraction of lipids and a smaller fraction of protein in their MFP than did R-heifers. Parenchyma weight and DNA were lower in E- than in R-heifers; however, when analyzed with age as a covariate term, treatment was no longer a significant term in the model. Level of nutrient intake had no effect on the lipid, protein, or hydroxyproline composition of the PAR. Collectively, these data demonstrate that PAR is refractory to the level of nutrient intake whereas MFP is not. Furthermore, the covariate analysis demonstrated that age at harvest, not the level of nutrient intake, was the single greatest determinant of total PAR DNA content.
Key Words: heifer • mammary development • nutrition
This article has been cited by other articles:
|
|
 |
|
  L. F. P. Silva, B. E. Etchebarne, M. S. Weber Nielsen, J. S. Liesman, M. Kiupel, and M. J. VandeHaar Intramammary Infusion of Leptin Decreases Proliferation of Mammary Epithelial Cells in Prepubertal Heifers J Dairy Sci, August 1, 2008; 91(8): 3034 - 3044. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. M. Daniels, S. R. Hill, K. F. Knowlton, R. E. James, M. L. McGilliard, and R. M. Akers Effects of Milk Replacer Composition on Selected Blood Metabolites and Hormones in Preweaned Holstein Heifers J Dairy Sci, July 1, 2008; 91(7): 2628 - 2640. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. E. Davis Rincker, M. S. Weber Nielsen, L. T. Chapin, J. S. Liesman, K. M. Daniels, R. M. Akers, and M. J. VandeHaar Effects of Feeding Prepubertal Heifers a High-Energy Diet for Three, Six, or Twelve Weeks on Mammary Growth and Composition J Dairy Sci, May 1, 2008; 91(5): 1926 - 1935. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. R Thorn, S. Purup, M. Vestergaard, K. Sejrsen, M. J Meyer, M. E Van Amburgh, and Y. R Boisclair Regulation of mammary parenchymal growth by the fat pad in prepubertal dairy heifers: role of inflammation-related proteins J. Endocrinol., March 1, 2008; 196(3): 539 - 546. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. R. Roche, J. M. Lee, K. A. Macdonald, and D. P. Berry Relationships Among Body Condition Score, Body Weight, and Milk Production Variables in Pasture-Based Dairy Cows J Dairy Sci, August 1, 2007; 90(8): 3802 - 3815. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. I. Zanton and A. J. Heinrichs The Effects of Controlled Feeding of a High-Forage or High-Concentrate Ration on Heifer Growth and First-Lactation Milk Production J Dairy Sci, July 1, 2007; 90(7): 3388 - 3396. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. M. Daniels, K. E. Webb Jr., M. L. McGilliard, M. J. Meyer, M. E. Van Amburgh, and R. M. Akers Effects of body weight and nutrition on mammary protein expression profiles in Holstein heifers. J Dairy Sci, November 1, 2006; 89(11): 4276 - 4288. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. Meyer, A. V. Capuco, D. A. Ross, L. M. Lintault, and M. E. Van Amburgh Developmental and nutritional regulation of the prepubertal bovine mammary gland: II. Epithelial cell proliferation, parenchymal accretion rate, and allometric growth. J Dairy Sci, November 1, 2006; 89(11): 4298 - 4304. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
