Nutrient Uptake and Endocrine Regulation of Milk Synthesis by Mammary Tissue of Lactating Sows

A method for the collection of mammary biopsies developed previously was refined and used to study the endocrine regulation of bovine milk protein gene expression. Our surgical biopsy method used real-time ultrasound imaging and epidural analgesia to enable recovery of a sufficient quantity of mammary tissue from late-pregnant dairy cows for explant culture in vitro. The time of biopsy was critical for prolactin-dependent induction of milk protein gene expression in mammary explants, as only mammary tissue from cows nearing 30 d prepartum was hormone-responsive. This suggests that during the later stages of pregnancy a change in the responsiveness of milk protein gene expression to endocrine stimuli occurred in preparation for lactation. This may relate to the diminution of a putative population of undifferentiated cells that were still responsive to prolactin. Alternatively, the metabolic activity of the tissue had increased to the level whereby the response of the tissue was no longer assessable using this model in vitro.

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Review: Mammary development in swine: effects of hormonal status, nutrition and management

Canadian Journal of Animal Science ◽

10.4141/cjas2012-066 ◽

2013 ◽

Vol 93 (1) ◽

pp. 1-7 ◽

Cited By ~ 13

Author(s):

C. Farmer

Keyword(s):

Detrimental Effect ◽

Current Knowledge ◽

Management Strategies ◽

Mammary Development ◽

Late Gestation ◽

Mammary Tissue ◽

Hormonal Status ◽

Best Management ◽

Lactating Sows ◽

Endocrine Status

Farmer, C. 2013. Review: Mammary development in swine: effects of hormonal status, nutrition and management. Can. J. Anim. Sci. 93: 1–7. There are three phases of rapid mammary accretion in swine, namely, from 90 d of age until puberty, during the last third of gestation and throughout lactation. Nutrition, endocrine status and management of gilts or sows during those periods can affect mammary development. More specifically, in growing gilts, feed restriction as of 90 d of age hinders mammary development and either supplying the phytoestrogen genistein or increasing circulating concentrations of prolactin stimulates mammogenesis. In late gestation, inhibition of relaxin or prolactin drastically diminishes mammary development and overly increasing dietary energy has a detrimental effect on mammogenesis. It also appears that feeding of the gestating sow can affect the mammary development of her offspring once it reaches puberty. Various management factors such as litter size, nursing intensity and use or non-use of a teat in the previous lactation will affect the amount of mammary tissue present at the end of lactation. Mammary development is followed by the essential process of involution whereby a rapid and drastic regression in parenchymal tissue takes place. It can occur either after weaning or in early lactation when teats are not being regularly suckled. Despite our current knowledge, much remains to be learned in order to develop the best management strategies for replacement gilts, and gestating and lactating sows that will maximize their milk production.

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Mammary metabolism in lactating sows: arteriovenous differences of milk precursors and the mammary metabolism of [14C]glucose and [14C]acetate

British Journal Of Nutrition ◽

10.1079/bjn19690039 ◽

1969 ◽

Vol 23 (2) ◽

pp. 319-333 ◽

Cited By ~ 55

Author(s):

J. L. Linzell ◽

T. B. Mepham ◽

E. F. Annison ◽

C. E. West

Keyword(s):

Amino Acids ◽

Blood Flow ◽

Fatty Acid ◽

Essential Amino Acids ◽

The Body ◽

Mammary Tissue ◽

Triglyceride Fraction ◽

Glucose Carbon ◽

Lactating Sows ◽

Mammary Metabolism

1. The following techniques, which have been applied successfully to goats, were used to study mammary metabolism in lactating sows:(I) measurements of mammary arteriovenous (A-V) differences in milk precursors in the conscious undisturbed animal (five sows); (2) continuous intravenous infusion of [U-14C]glucose with concomitant arterial and mammary venous blood sampling for measurement of mammary blood flow and specific radioactivity of glucose and CO, (one sow); (3) perfusion of the isolated gland in vitro (eight glands from four sows), with the inclusion of [U-14C]glucose (two glands) and [U-14C]acetate(two glands) in the substrate mixture.2. Sow mammary tissue was similar to that goats in its milk yield, blood flow, and glucose uptake per unit weight of tissue. As in goats, mammary uptake of glucose was many times that of the rest of the body and the total mammary tissue was utilizing about half of the total glucose entering the circulation. Glucose was a major source of milk lactose and glycerol and of mammary CO2.3. Of the plasma lipid components, only the triglyceride fraction was consistently and significantly removed by the gland. In contrast to the results obtained for the goat, both [U-14C[acetate and [U-14C]glucose carbon were used for milk fatty acid synthesis, and although the pattern of labelling of fatty acid from each precursor was similar, the formation of fatty acids from glucose was at least five times greater than that from acetate. Quantitative evaluation of the contribution of these precursors was not possible, but the RQ (1.09–1.63) suggest that in some instances it may have been considerable.4. The substantial A-V differences of most plasma essential amino acids suggest that these are the sole precursors of the corresponding residues in the mammary synthesized protein. The low A-V differences for several non-essential amino acids suggest that these are synthe- sized in the gland; this suggestion is supported by the incorporation of glucose carbon into non-essential amino acid residues of casein observed in one experiment. However, in contrast to results with the goat, mammary absorption of serine was consistently large.

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Intravenous infusion of glucose and insulin in relation to milk secretion in the sow

British Journal Of Nutrition ◽

10.1079/bjn19770006 ◽

1977 ◽

Vol 37 (1) ◽

pp. 45-53 ◽

Cited By ~ 10

Author(s):

L. Reynolds ◽

J. A. F. Rook

Keyword(s):

Fatty Acid Composition ◽

Plasma Glucose ◽

Glucose Concentration ◽

Intravenous Infusion ◽

Milk Fat ◽

Plasma Glucose Concentration ◽

Mammary Tissue ◽

Milk Secretion ◽

Lactating Sows ◽

The Difference

1. A comparison was made of the composition of milk from front and rear teats in four sows. There were small and not significant differences in fat, protein and lactose contents, and in the fatty-acid composition of the milk fat with the exception of the 18:3 acid where the difference was also small but significant.2. The effects of intravenous infusions of glucose and insulin in lactating sows on milk secretion and blood composition were investigated in two sows.3. Intravenous infusion of glucose had no effect on blood plasma glucose concentration but increased the yields of lactose, protein and water.4. Intravenous infusion of insulin depressed plasma glucose concentration and the yields of lactose and water. The yield of protein was unaffected.5. It is concluded that differences between the non-ruminant (the sow) and the ruminant in the responses in milk secretion to glucose infusion may be related to differences in the sensitivity to insulin of mammary tissue.

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Impact of arginine supplementation on serum prolactin and mRNA abundance of amino acid transporter genes in mammary tissue of lactating sows

Journal of Animal Science ◽

10.1093/jas/skaa335 ◽

2020 ◽

Vol 98 (11) ◽

Author(s):

Uffe Krogh ◽

Chantal Farmer ◽

Lee-Anne Huber ◽

Peter K Theil ◽

Nathalie L Trottier

Keyword(s):

Feed Intake ◽

Late Pregnancy ◽

Transcript Abundance ◽

Mrna Abundance ◽

Control Treatment ◽

Serum Prolactin ◽

Mammary Tissue ◽

Control Group ◽

Parenchymal Tissue ◽

Lactating Sows

Abstract This study was conducted to test the hypothesis that supplemental dietary Arg to late-pregnant and lactating sows increases serum prolactin concentrations and mRNA abundance of SLC7A1, SLC7A2, and SLC6A14 in mammary parenchymal tissue. From day 108 of gestation and until day 21 of lactation, sows were fed a diet either supplemented with 0.10 g of l-Arg/kg body weight (BW) per day (n = 10, ARG) or 0.34 g of l-Glu/kg BW per day (n = 10, control). Litters were standardized to 10 piglets on day 1 of lactation and piglets were weighed on days 1, 7, 14, and 21 of lactation. Sow BW was recorded on day 108 of gestation and days 1, 10, and 21 of lactation. Lactation sow feed intake was recorded daily. Mammary parenchymal tissue was biopsied on day 5 of lactation to measure mRNA abundance SLC7A1, SLC7A2, and SLC6A14. On days 4 and 18 of lactation, blood samples were collected from sows at 2, 4, and 6 hr postfeeding to measure serum prolactin concentrations. Milk samples were collected on days 4, 10, and 18 of lactation to measure fat, lactose, urea N, and true protein concentrations. Sow BW, backfat, and feed intake over all sampling days did not differ between treatments. Piglet BW on d 1 tended to be greater for the ARG treatment than the control treatment (P = 0.12). Sow milk yield and composition (fat, protein, lactose, and urea N) and mammary mRNA abundance of candidate genes did not differ between the ARG and the control group. Compared to controls, serum prolactin concentrations tended to be greater (P = 0.08) in ARG sows on day 4 of lactation, and did not differ on day 18. Current findings show a potential beneficial effect of dietary supplementation with Arg to late-pregnant multiparous sows on BW of their piglets on day 1. Dietary Arg supplementation at a rate of 0.10 g/kg BW during late pregnancy and lactation tended to increase serum prolactin concentrations with no increase in mammary transcript abundance of SLC7A1, SLC7A2, and SLC6A14 in early lactation.

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Endocrinology and mammary development of lactating Genex-Meishan and Large White sows

Canadian Journal of Animal Science ◽

10.4141/a03-055 ◽

2003 ◽

Vol 83 (4) ◽

pp. 731-737 ◽

Cited By ~ 1

Author(s):

C. Farmer ◽

M. F. Palin ◽

M. T. Sorensen

Keyword(s):

Mammary Glands ◽

Mammary Development ◽

Serum Prolactin ◽

Mammary Tissue ◽

Prolactin Receptors ◽

Tissue Composition ◽

Large White ◽

Lactating Sows ◽

Igf I ◽

Plasma Ffa

Endocrine and metabolic data as well as mammary tissue composition were obtained in Genex-Meishan (GM, containing 50% Chinese Meishan genes) and Large White (LW) lactating sows. Jugular vein cannulae were used to collect serial blood samples from 9 LW and 8 GM sows for 4 h every 15 min on days 6 and 19 of lactation. Concentrations of prolactin and cortisol were determined on all samples while those of insulin-like growth factor-I (IGFI), growth hormone (GH), glucose and free fatty acids (FFA) were measured in hourly samples. Milk samples were obtained from 19 GM and 16 LWsows on day 23 of lactation and all sows were slaughtered on day 25. Mammary glands were excised and analyzed for tissue composition and for number and affinity of prolactin receptors. Concentrations of plasma IGF-I were lower (P < 0.01) and plasma FFA greater (P < 0.001) in GM than in LW sows. On day 6 of lactation, serum prolactin (P < 0.05) and cortisol (P < 0.01) concentrations were greater and glucose values lower (P < 0.001) in GM than in LW sows. The concentration of IGFI in lactoserum was lower (P < 0.001) while that of prolactin was greater (P < 0.05) in GM compared to LW sows on day 23 of lactation. There was less (P < 0.001) residual milk and more (P < 0.05) parenchymal RNA in mammary glands from GM compared to LW sows. The affinity of prolactin receptors was also greater (P < 0.05) in GM than in LW sows. The better emptying of mammary glands by litters from GM sows and the greater circulating concentrations of prolactin in early lactation as well as the greater affinity of mammary prolactin receptors may be related to the great milking potential of Meishan-derived sows. Key words: Hormones, lactation, mammary gland, Meishan, prolactin, sows

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Formation and Structure of Casein Micelles in Lactating Mammary Tissue

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100067741 ◽

1970 ◽

Vol 28 ◽

pp. 150-151

Author(s):

Robert J. Carroll ◽

Marvin P. Thompson ◽

Harold M. Farrell

Keyword(s):

Size Distribution ◽

G Protein ◽

Milk Proteins ◽

Mammary Tissue ◽

Colloidal System ◽

Casein Micelles ◽

The Stability

Milk is an unusually stable colloidal system; the stability of this system is due primarily to the formation of micelles by the major milk proteins, the caseins. Numerous models for the structure of casein micelles have been proposed; these models have been formulated on the basis of in vitro studies. Synthetic casein micelles (i.e., those formed by mixing the purified αsl- and k-caseins with Ca2+ in appropriate ratios) are dissimilar to those from freshly-drawn milks in (i) size distribution, (ii) ratio of Ca/P, and (iii) solvation (g. water/g. protein). Evidently, in vivo organization of the caseins into the micellar form occurs in-a manner which is not identical to the in vitro mode of formation.

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Effect of Some Natural Mineral Waters in Nutrient Uptake by Caco-2 Cells

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000013 ◽

2010 ◽

Vol 80 (2) ◽

pp. 131-143 ◽

Cited By ~ 3

Author(s):

Pedro Gonçalves ◽

João R. Araújo ◽

Fátima Martel

Keyword(s):

Nutrient Uptake ◽

Mineral Waters ◽

Distilled Water ◽

Natural Mineral ◽

Minute Exposure

We studied the effect of some mineral waters and some of their constituents on the apical uptake of 14C-butyrate (14C-BT) and 3H-O-methyl-D-glucose (3H-OMG) by Caco-2 cells. Uptake of 14C-BT increased after a 20-minute exposure to 1 % (v/v) distilled water, and, compared to distilled water, it was decreased by Pedras Salgadas® 1 % (v/v) and Melgaço® 5 % (v/v), and increased by Vidago® 5 % (v/v). Moreover, it increased after a 48-hour exposure to Vidago® or Melgaço® waters (5 % (v/v)). Also, uptake of 14C-BT was reduced after a 20-minute exposure to MgCl2, MgSO4, or CaCl2. Uptake of 3H-OMG was reduced after a 20-minute exposure to Melgaço® water [1 % (v/v)], when compared to distilled water. Also, a 48-hour exposure to Pedras Salgadas® or Melgaço® water (5 % (v/v)) increased and decreased uptake, respectively. Finally, uptake of 3H-OMG decreased after a 20-minute exposure to MgSO4 or NaF. In conclusion, uptake of 14C-BT and 3H-OMG by Caco-2 cells is differently modulated by distinct mineral waters.

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