Journal
ANIMAL
Volume 10, Issue 12, Pages 2008-2017Publisher
CAMBRIDGE UNIV PRESS
DOI: 10.1017/S1751731116000987
Keywords
dairy cow; gene expression; growth hormone; lactation; mammary glands
Funding
- Ministry of Business, Innovation, and Employment [C10 x 0702]
- AgResearch Initiative Funds
- Ministry of Business, Innovation, and Employment Postdoctoral Fellowship
- Marsden Fast Start Fund
- CAPES PhD scholarship
- National Council for Scientific and Technological Development - CNPq Post-doctoral Scholarship from the Federal Government of Brazil
Ask authors/readers for more resources
The galactopoietic effect of growth hormone (GH) in lactating ruminants is well established; however the mechanisms that mediate these effects are not well understood. The first objective of this study was to determine the effect of GH on the synthesis of the major casein and whey proteins. The second objective was to identify the genes and pathways that may be involved in mediating the effect of GH on milk synthesis. A single subcutaneous injection of a commercially available slow release formulation of GH (Lactatropin (R)), or physiological saline solution (control) was administered to non-pregnant dairy cows (n = 4/group) in mid-late lactation. Milk samples were collected for composition analysis and mammary lobulo-alveolar tissue was collected postmortem 6 days post injection. Gene expression profiles were evaluated using either a 22 000 bovine complementary DNA microarray or quantitative PCR (qPCR), and microarrays were validated by qPCR. The yield of all the major casein and whey proteins was increased 32% to 41% in GH-treated cows, with the exception of alpha-lactalbumin yield which was elevated by 70% relative to controls. Treatment with GH treatment tended to increase the concentration of alpha-lactalbumin but had no effect on the concentration of any of the major milk proteins. Messenger RNA (mRNA) abundance of the major whey and casein genes, with the exception of alpha-s2-casein, was increased in response to GH compared with controls, which is consistent with the positive effect of GH on milk production. Treatment with GH treatment influenced the mRNA abundance of genes involved in cell growth and proliferation, transcriptional and translational regulation, actin cytoskeleton signalling, lipid metabolism and cell death. This study has provided new insights into the cell signalling that may be involved in mediating the effect of GH on milk production in the mammary gland of lactating dairy cows.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available