0845 Effect of 17β-estradiol on milk production, hormone secretion, and mammary gland gene expression of dairy cows

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 406-407
Author(s):  
J. J. Tong ◽  
I. M. Thompson ◽  
P. Lacasse
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Dairy Cows ◽  
Milk Production ◽  
Hormone Secretion ◽  
17Β Estradiol

445 Toxy-Nil and Unike Plus modulate differences in gene expression of milk somatic cells isolated from mammary gland of lactating dairy cows fed aflatoxin B1

2017 ◽  
Vol 95 (suppl_4) ◽  
pp. 218-219
Author(s):  
R. O. Rodrigues ◽  
R. O. Rodrigues ◽  
D. R. Ledoux ◽  
G. E. Rottinghaus ◽  
R. Borutova ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Dairy Cows ◽  
Aflatoxin B1 ◽  
Somatic Cells ◽  
Lactating Dairy Cows ◽  
Milk Somatic Cells

Downregulation of Estrogen Receptor Gene Expression by Exogenous 17β-Estradiol in the Mammary Glands of Lactating Mice

2006 ◽  
Vol 231 (3) ◽  
pp. 311-316 ◽  
Author(s):  
Toshinobu Hatsumi ◽  
Yutaka Yamamuro
Keyword(s):  
Gene Expression ◽  
Estrogen Receptor ◽  
Mammary Gland ◽  
Single Injection ◽  
Receptor Gene ◽  
Self Regulation ◽  
Estrogen Receptor Gene ◽  
17Β Estradiol ◽  
Nuclear Estrogen Receptor ◽  
Receptor Gene Expression

The biological actions of estrogen are mostly conveyed through interaction with the nuclear estrogen receptor (ER). Previous evidence indicated that estrogen participates in self-regulation through the modulation of the expression of its own receptors. However, the self-regulation of estrogen against ER in the mammary gland during established lactation has not yet been investigated. The present study evaluated ER gene expression in the lactating gland activated by large doses of 17β-estradiol (E2). Repeated E2 treatments dose-dependently decreased the gene, expression of ER, especially its subtype ER-α mRNA, Which was decreased to 10% of the vehicle-injected control by 1 μg E2 injection, whereas it was decreased by 73% for another subtype, ER-β. A single injection of 5 μg of E2 drastically downregulated both ER genes within 12 hrs of injection, and they did not recover to pretreatment level within 48 hrs. Western blot analysis verified that E2 treatment inhibited the phosphorylation of Stat5, which is a potent transcriptional regulator for ER mRNA. The present findings demonstrate that E2 treatment decreases the gene expression of its own receptor in the mammary gland during galactopoesis and induces an apparent transition of the ER profile in the mammary gland during lactation into postlactation.

A review of bovine growth hormone

1994 ◽  
Vol 74 (2) ◽  
pp. 167-201 ◽  
Author(s):  
Jeanne L. Burton ◽  
Brian W. McBride ◽  
Elliot Block ◽  
David R. Glimm ◽  
John J. Kennelly
Keyword(s):  
Growth Hormone ◽  
Mammary Gland ◽  
Growth Factor ◽  
Dairy Cows ◽  
Milk Production ◽  
Reproductive Efficiency ◽  
Bovine Growth Hormone ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Exogenous Growth

Unprecedented numbers of technical papers, abstracts, and short communications have been published in the past decade regarding the effects of exogenous bovine growth hormone on milk production, health, and reproductive efficiency of treated dairy cows. In well-managed dairy herds, exogenous growth hormone increases milk production without altering normal variability in milk composition. This has held true regardless of dairy breed tested, geographical location studied, or feeding management system used. Also consistent across studies is the rapidity of the galactopoietic effect of administered bovine growth hormone, which arises from altered partitioning and use of post-absorptive nutrients and increased synthetic capacity of the mammary gland. Growth hormone and its associated peptide, insulin-like growth factor-I, are now known to provide chronic lipolytic, diabetogenic, and gluconeogenic signals to target tissues culminating in increased mammary gland availability of glucose and nonesterified fatty acids. Together with yet ill-defined effects on mammary secretory tissue, this homeorhetic control of metabolism elicited by exogenous growth hormone is so efficient that treated cows are not more susceptible to metabolic disorders than untreated cows. However, some studies have reported an increased frequency of mastitis in groups of treated cows. This has been attributed mainly to increased milk volume in the mammary glands of treated cows and no convincing data are available that show decreased mammary gland immunity as a result of growth hormone treatments. On the contrary, an expanding body of evidence implicates growth hormone as a key neuroendocrine factor that is required for immunological competence. Trends of decreased reproductive efficiency in cows treated with growth hormone have also been reported, but available data imply that this is probably an indirect effect via prolonged negative energy balance in cows treated in early lactation rather than a direct negative effect on estrous cycling via altered reproductive hormone profiles. The objectives of the present review are to bring into focus and summarize pertinent biological discoveries regarding the treatment of dairy cows with recombinant bovine growth hormone, and to explore areas where additional growth hormone research is needed or warranted. Key words: Growth hormone, somatotropin, dairy cows, insulin-like growth factor-I

scholarly journals The role of rumen-protected choline in hepatic function and performance of transition dairy cows

2016 ◽  
Vol 116 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Arash Shahsavari ◽  
Michael J. D’Occhio ◽  
Rafat Al Jassim
Keyword(s):  
Gene Expression ◽  
Fatty Acids ◽  
Dairy Cows ◽  
Milk Production ◽  
Transition Period ◽  
Hepatic Function ◽  
Negative Energy ◽  
Liver Fat ◽  
Economic Losses ◽  
Negative Effects

AbstractHigh-producing dairy cows enter a period of negative energy balance during the first weeks of lactation. Energy intake is usually sufficient to cover the increase in energy requirements for fetal growth during the period before calving, but meeting the demand for energy is often difficult during the early stages of lactation. A catabolic state predominates during the transition period, leading to the mobilisation of energy reserves (NEFA and amino acids) that are utilised mainly by the liver and muscle. Increased uptake of mobilised NEFA by the liver, combined with the limited capacity of hepatocytes to either oxidise fatty acids for energy or to incorporate esterified fatty acids into VLDL results in fatty liver syndrome and ketosis. This metabolic disturbance can affect the general health, and it causes economic losses. Different nutritional strategies have been used to restrict negative effects associated with the energy challenge in transition cows. The provision of choline in the form of rumen-protected choline (RPC) can potentially improve liver function by increasing VLDL exportation from the liver. RPC increases gene expression of microsomal TAG transfer protein and APOB100 that are required for VLDL synthesis and secretion. Studies with RPC have looked at gene expression, metabolic hormones, metabolite profiles, milk production and postpartum reproduction. A reduction in liver fat and enhanced milk production has been observed with RPC supplementation. However, the effects of RPC on health and reproduction are equivocal, which could reflect the lack of sufficient dose–response studies.

0850 Consumption of endophyte-infected fescue seed during the dry period and lactation affects mammary gland gene expression in dairy cows

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 409-409
Author(s):  
R. L. Baldwin ◽  
C. Li ◽  
D. M. Bickhart ◽  
C. M. Evock-Clover ◽  
P. Grossi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Dairy Cows ◽  
Dry Period

scholarly journals Supplements of vitamins B9 and B12 affect hepatic and mammary gland gene expression profiles in lactating dairy cows

BMC Genomics ◽  
2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Bazoumana Ouattara ◽  
Nathalie Bissonnette ◽  
Melissa Duplessis ◽  
Christiane L. Girard
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Dairy Cows ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Lactating Dairy Cows

Localization and expression of BCAT during pregnancy and lactation in the rat mammary gland

2001 ◽  
Vol 280 (3) ◽  
pp. E480-E488 ◽  
Author(s):  
Armando R. Tovar ◽  
Enrique Becerril ◽  
Rogelio Hernández-Pando ◽  
Gabriel López ◽  
Agus Suryawan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Milk Production ◽  
Acinar Cells ◽  
Progressive Increase ◽  
Female Rats ◽  
Specific Staining ◽  
Pregnancy And Lactation ◽  
Branched Chain ◽  
Immunohistochemical Studies

During lactation, branched-chain aminotransferase (BCAT) gene expression increases in the mammary gland. To determine the cell type and whether this induction is present only during lactation, female rats were randomly assigned to one of three experimental groups: pregnancy, lactation, or postweaning. Mammary gland BCAT activity during the first days of pregnancy was similar to that of virgin rats, increasing significantly from day 16 to the last day of pregnancy. Maximal BCAT activity occurred on day 12 of lactation. During postweaning, BCAT activity decreased rapidly to values close to those observed in virgin rats. Analyses by Western and Northern blot revealed that changes in enzyme activity were accompanied by parallel changes in the amount of enzyme and its mRNA. Immunohistochemical studies of the mammary gland showed a progressive increase in mitochondrial BCAT (mBCAT)-specific staining of the epithelial acinar cells during lactation, reaching high levels by day 12. Immunoreactivity decreased rapidly after weaning. There was a significant correlation between total BCAT activity and milk production. These results indicate that the pattern of mBCAT gene expression follows lactogenesis stages I and II and is restricted to the milk-producing epithelial acinar cells. Furthermore, BCAT activity is associated with milk production in the mammary gland during lactation.

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