To better understand the role of nutrition in regulating mammary gland development and lactation, we designed a novel stair-step compensatory nutrition regimen that is a unique combination of dietary energy restriction and realimentation (refeeding) phases; the basic concept of this regimen is to exploit the biological nature of the compensatory growth phenomenon in concert with one or more hor...

Maningat PD, Sen P, Rijnkels M, Sunehag AL, Hadsell DL, Bray M, Haymond MW. Gene expression in the human mammary epithelium during lactation: the milk fat globule transcriptome. Physiol Genomics 37: 12–22, 2009. First published November 18, 2008; doi:10.1152/physiolgenomics.90341.2008.—The molecular physiology underlying human milk production is largely unknown because of limitations in obtaini...

The aim of this experiment was to demonstrate the ability of feeding serotonin (5-HT; 5-hydroxytryptamine) precursors to increase 5-HT production during the transition from pregnancy to lactation and the effects this has on maternal energy metabolism in the liver and mammary gland. Pregnant rats (n = 45) were fed one of three diets: I) control (CON), II) CON supplemented with 0.2% 5-hydroxytryp...

Heat stress (HT) during the dry period compromises mammary gland development, decreases future milk production, and impairs the immune status of dairy cows. Our objective was to evaluate the effect of cooling HT cows during the dry period on gene expression of the mammary gland and peripheral blood mononuclear cells (PBMC). Cows were dried off 46 d before their expected calving and assigned to ...

The delivery of copper to mammary gland and milk and the effects of lactation were examined in rats. Traces of (67)Cu/(64)Cu(II) were injected intraperitoneally or intravenously into virgin rats or lactating rats (2-5 days postpartum), and incorporation into blood, milk, and tissues was monitored. In virgin rats, most of the isotope first entered the liver and kidney. In lactating rats, almost ...

An increase in the plane of energy nutrition of the cow is known to increase both the yield and the solids-not-fat (s.N.F.) content of milk: a decrease in fat content also occurs but there is little effect on the yield of fat (for review of literature, see Burt, 1957 a). Though small depressions in milk lactose content occur with underfeeding (Rowland, 1946), any change in S.N.F. content is lar...

Expression of insulin receptor substrates (IRS)-1 and -2 within the mammary gland was found to be high at mid-lactation and dramatically decreased with mammary involution. This observation supports the hypothesis that these proteins are induced in the mammary gland with lactogenesis and involved in normal milk synthesis. To test this hypothesis, lactation capacity, along with indices of mammary...

Cohen-Zinder M, Donthu R, Larkin DM, Kumar CG, RodriguezZas SL, Andropolis KE, Oliveira R, Lewin HA. Multisite haplotype on cattle chromosome 3 is associated with quantitative trait locus effects on lactation traits. Physiol Genomics 43: 1185–1197, 2011. First published September 6, 2011; doi:10.1152/physiolgenomics.00253.2010.—The goal of this study was to identify candidate genes and DNA poly...

Milk is a source of bioactive molecules with wide-ranging functions. Among these, the immune properties have been the best characterised. In recent years, it has become apparent that besides the immunoglobulins, milk also contains a range of minor immune-related proteins that collectively form a significant first line of defence against pathogens, acting both within the mammary gland itself as ...

1. Arteriovenous differences of plasma free amino acids across the lactating mammary glands of six goats have been measured. 2. In four experiments, measurements of blood flow, amino acid arteriovenous differences, milk yield and milk nitrogen showed that the uptake of nitrogen in the form of amino acids was sufficient to provide all the nitrogen of the milk proteins synthesized in the mammary ...