Skip to main content

Research Repository

Advanced Search

The effects of milking frequency in early lactation on milk yield, mammary cell turnover, and secretory activity in grazing dairy cows

Murney, R.; Margerison, J. K.; Stelwagen, K.; Wheeler, T.T.; Singh, K.

Authors

R. Murney

K. Stelwagen

T.T. Wheeler

K. Singh



Abstract

In dairy cows, short-term changes of milking frequency in early lactation have been shown to produce an immediate and a long-term effect on milk yield in stall-fed cows. The effect is controlled locally within mammary glands and could be a function of either secretory mammary epithelial cell number or activity. To resolve this and determine its applicability in other feed management systems, a unilateral milking frequency experiment was conducted with udder halves of 17 multiparous, pasture-fed dairy cows milked either 4 times (4×) or once a day (1×) for 14 d from 5 ± 2 d in milk. Mean half-udder milk yield during the treatment period was higher from the 4× compared with 1× udder halves and continued to be higher until 200 d in milk once returned to twice a day milking. Mammary biopsies were obtained on d 14 of treatment from both udder halves of 10 cows. Proliferation of mammary cells was higher in 4× udder halves compared with 1×, whereas no difference in apoptosis levels was detected. Abundance of αS1-casein, β-casein, α-lactalbumin, and β-lactoglobulin mRNA was higher in tissue samples from 4× udder halves compared with 1×, whereas lactoferrin mRNA abundance was lower in 4× udder halves. In summary, change in milking frequency during early lactation affects proliferation of mammary cells as well as expression of the major milk protein genes, which both contribute to the observed changes in milk yield during and after unilateral milking frequency treatment.

Citation

Murney, R., Margerison, J. K., Stelwagen, K., Wheeler, T., & Singh, K. (2015). The effects of milking frequency in early lactation on milk yield, mammary cell turnover, and secretory activity in grazing dairy cows. Journal of Dairy Science, 98(1), 305-311. https://doi.org/10.3168/jds.2014-8745

Journal Article Type Article
Acceptance Date Oct 8, 2014
Online Publication Date Nov 20, 2014
Publication Date Jan 1, 2015
Deposit Date Aug 3, 2017
Journal Journal of Dairy Science
Print ISSN 0022-0302
Electronic ISSN 1525-3198
Publisher American Dairy Science Association
Peer Reviewed Peer Reviewed
Volume 98
Issue 1
Pages 305-311
DOI https://doi.org/10.3168/jds.2014-8745
Keywords milking frequency, grazing dairy cow, early lactation, milk yield, cell proliferation
Public URL https://nottingham-repository.worktribe.com/output/1115891
Publisher URL https://www.journalofdairyscience.org/article/S0022-0302(14)00803-0/fulltext
Related Public URLs https://www.sciencedirect.com/science/article/pii/S0022030214008030
PMID 00034662