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

2003 ◽  
Vol 83 (4) ◽  
pp. 731-737 ◽  
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

Use of recorded nursing grunts during lactation in two breeds of sows. II. Effects on sow performance and mammary development

2004 ◽  
Vol 84 (4) ◽  
pp. 581-587 ◽  
Author(s):  
C. Farmer ◽  
K. Fisette ◽  
S. Robert ◽  
H. Quesnel ◽  
J. P. Laforest
Keyword(s):  
Dry Matter ◽  
Mammary Glands ◽  
Milk Composition ◽  
Cell Number ◽  
Mammary Development ◽  
Mammary Cell ◽  
Lactating Sows ◽  
Igf I ◽  
Total Dna ◽  
Group 1

Primiparous lactating sows of two different genotypes [42 Genex-Meishan hybrid (MH) and 42 Yorkshire-Landrace (YL)] were exposed to recorded nursing grunts played at different intervals, and the effects on sow performance and mammary growth were studied. Sows within each breed were divided in three groups (n = 14 for each group): (1) no playbacks (control), (2) playbacks at 35-min interv als (GR35), and (3) playbacks at 40-min intervals (GR40). Recordings were played from day 110 of gestation to day 28 of lactation. Litter size was standardized to 10 ± 1 pigs within 48 h postpartum, and weight and backfat thickness of sows were recorded on day 110 of gestation, and on days 2 and 27 of lactation. Sow feed and water intakes were recorded throughout lactation. Milk samples were obtained from all sows on day 27 postpartum and jugular blood samples were obtained on day 28 for measurement of IGF -I and prolactin concentrations. Sows were slaughtered on day 28 of lactation and their mammary glands were excised to perform compositional analyses. Ovaries were also collected. The MH sows weighed less (P < 0.01) and had more backfat (P < 0.01) than YL sows. Milk from MH sows contained more dry matter (P < 0.05) and more lactose (P < 0.05) than that from YL sows. Mammary parenchymal tissue weighed less (P < 0.05) and contained less total protein (P = 0.01) and total DNA (P < 0.01) in MH than in YL sows. Sows in GR35 also had more total parenchymal DNA (P < 0.05) than control sows. Circulating concentrations of IGF-I and prolactin were not affected by breed or treatment (P > 0.1) whereas ovaries were heavier (P < 0.01) in control MH than in control YL ows. Therefore, playbacks of nursing grunts at 35-min intervals throughout lactation increased total mammary cell number without affecting hormonal or milk composition status. Key words: Auditory stimulus, lactation, mammary development, Meishan, milk, sows

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

2013 ◽  
Vol 93 (1) ◽  
pp. 1-7 ◽  
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.

scholarly journals The expression of the IGF family and GH receptor in the bovine mammary gland

2001 ◽  
Vol 168 (1) ◽  
pp. 39-48 ◽  
Author(s):  
A Plath-Gabler ◽  
C Gabler ◽  
F Sinowatz ◽  
B Berisha ◽  
D Schams
Keyword(s):  
Mammary Gland ◽  
Binding Proteins ◽  
Mammary Development ◽  
Mammary Tissue ◽  
Bovine Mammary Gland ◽  
Igf Binding Proteins ◽  
Gh Receptor ◽  
Igf I ◽  
Temporal Expressions ◽  
Igfbp 3

To study the involvement of the IGFs in mammary development and lactation of the cow, the temporal expressions of IGF-I and -II, its receptor type 1 (IGFR-1), IGF-binding proteins (IGFBPs)-1 to -6 and GH receptor (GHR) mRNA were examined. This was carried out for different stages of mammogenesis, lactogenesis, galactopoiesis and involution in the bovine mammary gland of 26 animals. Furthermore, IGF-I was localised by immunohistochemistry. The highest mRNA concentrations for IGF-I were detected in the mammary tissue of late pregnant heifers (days 255-272) and significantly lower expression was detected during lactogenesis and galactopoiesis. Immunohistochemistry of IGF-I revealed only a weak staining in the epithelium of the ducts during mammogenesis. The epithelium of the alveoli were negative during mammogenesis, lactogenesis and galactopoiesis but displayed distinct IGF-I activity during involution. In the stroma a distinct staining of the cytoplasm of adipocytes and of vascular smooth muscle cells was observed. A certain percentage of fibroblasts (usually 20-30%) were also immunopositive. In contrast, highest expression for IGFR-1 was detected during galactopoiesis and involution. The lowest mRNA concentration for IGFR-1 was found during pregnancy (days 194-213). In general, the expression of IGF-II was not regulated during mammogenesis and lactation, but decreased during involution. The mRNA for the six binding proteins was detected in the bovine mammary gland. The dominant binding proteins were IGFBP-3 and -5. The highest expression of IGFBP-3 was observed during mid-pregnancy and the lowest during late lactation, involution and in non-pregnant heifers. The mRNA for IGFBP-5 increased during late mammogenesis and lactogenesis followed by a decrease thereafter. In general, the mRNA concentrations for IGFBP-2, -4 and -6 were barely detectable during all stages. In contrast, the expression for IGFBP-1 was upregulated in the mammary gland of virgin heifers and increased around the onset of lactation. mRNA for GHR was found during all stages examined without outstanding fluctuations. In conclusion, locally produced IGF-I and -II may mediate mammogenesis. The high mammary IGFR-1 mRNA during lactation suggests a role for peripheral IGF-I in maintenance of lactation. The role of IGFBPs in the mammary gland needs further evaluation.

scholarly journals Effect of hypothyroidism on hormone profiles in virgin, pregnant and lactating rats, and on lactation

Reproduction ◽  
2003 ◽  
pp. 371-382 ◽  
Author(s):  
MB Hapon ◽  
M Simoncini ◽  
G Via ◽  
GA Jahn
Keyword(s):  
Late Pregnancy ◽  
Thyroid Stimulating Hormone ◽  
Mammary Development ◽  
Serum Prolactin ◽  
Pregnant Rats ◽  
Stunted Growth ◽  
Igf I ◽  
Milk Ejection Reflex ◽  
Thyroid Dysfunctions ◽  
Serum Tsh

Thyroid dysfunctions can produce reproductive problems. Untreated maternal hypothyroidism has serious consequences on development of offspring, resulting in stunted growth and mental retardation. The effects of propylthiouracyl-induced hypothyroidism (0.1 g l(-1) in drinking water starting 8 days before mating, or given to virgin rats for 30 or 50 days) on the serum profiles of hormones related to reproduction and mammary function (prolactin, growth hormone (GH), progesterone, corticosterone, oestradiol, insulin-like growth factor I (IGF-I), thyroid-stimulating hormone (TSH), triiodothyronine and tetraiodothyronine), and on mammary function in virgin, pregnant and lactating rats, were investigated. Propylthiouracyl treatment severely decreased circulating triiodothyronine and tetraiodothyronine concentrations, and increased serum TSH concentrations. Virgin rats showed prolonged periods of vaginal dioestrus, increased circulating progesterone concentrations and afternoon peaks of prolactin concentration, which are indicative of prolactin-induced pseudopregnancy. Propylthiouracyl-treated virgin rats had mammary development comparable to that of midpregnancy, and half of these rats had increased mammary casein and lactose concentrations. Serum prolactin concentrations were decreased on the afternoon of day 5 of pregnancy, increased during late pregnancy (days 15-21) and were normal during lactation. Circulating GH concentrations decreased on days 15-21 of pregnancy, whereas progesterone concentrations increased during late pregnancy and early lactation. Circulating oestradiol (measured in late pregnancy and in virgin rats), IGF-I and corticosterone concentrations were decreased. Although assessment of mammary histology showed no differences in extent of development, casein content was increased in propylthiouracyl-treated rats on day 21 of pregnancy; litter growth was severely reduced and at day 20 of age the pups were hypothyroid, with decreased GH serum concentrations. An acute suckling experiment was performed on days 10-12 of lactation to determine whether some impairment in mammary function or the suckling reflex might account for these differences. After an 8 h separation of mothers from their litters and 30 min of suckling, circulating prolactin values were not affected by propylthiouracyl treatment, but serum oxytocin concentration and milk excretion were reduced. In conclusion, hypothyroidism induces various alterations in the hormone profiles of virgin and pregnant rats, and induces pseudopregnancies and mammary development in virgin rats. These alterations do not appear to have an overt impact on the outcome of pregnancy and on mammary function during lactation, with the exception of the milk ejection reflex, which may account at least partially for the reduced litter growth.

THE EFFECT OF THE ANTI-ANDROGEN 1,2α-METHYLENE-6-CHLORO-Δ4,6-PREGNADIENE-17α-OL-3,20-DIONE-17α-ACETATE (CYPROTERONE ACETATE) ON THE DEVELOPMENT OF THE MAMMARY GLANDS OF MALE FOETAL RATS

1966 ◽  
Vol 36 (4) ◽  
pp. 347-NP ◽  
Author(s):  
F. NEUMANN ◽  
W. ELGER
Keyword(s):  
Cyproterone Acetate ◽  
Mammary Glands ◽  
Gonadal Hormones ◽  
Mammary Development ◽  
Mammary Tissue ◽  
Glandular Tissue ◽  
Pregnant Rats

SUMMARY Treatment of pregnant rats with an anti-androgen (1,2α-methylene-6-chloro-Δ4,6-pregnadiene-17α-ol-3,20-dione-17α-acetate, 'cyproterone acetate') from the 13th day of pregnancy resulted in female organogenesis of the mammary glands, including the formation of nipples in the male foetuses and feminization of other male sexual characters. The continued development of the nipple primordium was also seen in all the subsequent foetal and postnatal stages even after termination of the treatment. A more marked development of the foetal mammary tissue as compared with that of male controls was noted in the proximal areas of the mammary cord process between the 19th and the 21st day in male foetuses whose mothers had received the anti-androgen. In male foetuses of treated mothers, a further proliferation of the glandular tissue was also found after birth. The role of androgens in the development of the mammary glands is discussed. It seems likely from our findings that the androgens of a male foetus inhibit the development of the mammary glands, emphasizing that for mammary development before puberty female gonadal hormones are not necessary.

Suppression of ovarian secretions before puberty strongly affects mammogenesis in the goat

2012 ◽  
Vol 79 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Lucile Yart ◽  
Laurence Finot ◽  
Pierre-Guy Marnet ◽  
Frédéric Dessauge
Keyword(s):  
Mammary Gland ◽  
Progesterone Receptors ◽  
Antigen Expression ◽  
Mammary Glands ◽  
Cell Number ◽  
Mammary Development ◽  
Border Region ◽  
Nuclear Antigen ◽  
Mammary Tissue ◽  
Pcr Analysis

The objective of this study was to provide insight into the biological mechanisms underlying mammary development and the role of the ovaries in prepubertal caprine mammogenesis using a serial ovariectomy approach. Young Alpine goats were ovariectomized (Ovx) or sham-operated (Int) at three periods before puberty (G1=1 month, G2=2 month and G3=3 months of age) and one after puberty (G7=7 months of age). The goats were slaughtered at 9 months of age and mammary glands were removed. Ovariectomy performed at 1, 2 and 3 months of age caused a 50% reduction in DNA concentration, in mammary tissue taken from the parenchyma-stroma border region. Morphological analysis of mammary tissue sections indicated that the parenchymal structures of Ovx goats were negatively affected by ovariectomy. Goats ovariectomized before 2 months of age (Ovx-1 and Ovx-2) showed a significant decrease in the percent of cells proliferating in mammary glands of 9-month old goats (proliferating cell nuclear antigen expression and antigen Ki67-positive cell number). Also, goats ovariectomized at 1 and 2 months of age had reduced matrix metalloprotease 2 activity at 9 months of age. E-cadherin was strongly decreased in goats ovariectomized before 2 months of age (80 and 85% in Ovx-1 and Ovx-2 goats, respectively). Quantitative PCR analysis of transcripts encoding for oestrogen (ERα) and progesterone receptors (PR) and immunodetection of ERα showed that ovariectomy at 1 and 2 months of age strongly inhibited the transcription of ERα and PR in the mammary gland. We conclude that ovariectomy before 3 months of age markedly impaired parenchymal development. These findings suggest that prepubertal mammogenesis in goats depends on the ovaries to initiate mammary epithelial cell proliferation and mammary gland remodelling.

scholarly journals Insulin-like growth factor binding protein-5 (IGFBP-5) induces premature cell death in the mammary glands of transgenic mice

Development ◽  
2002 ◽  
Vol 129 (19) ◽  
pp. 4547-4557 ◽  
Author(s):  
Elizabeth Tonner ◽  
Michael C. Barber ◽  
Gordon J. Allan ◽  
James Beattie ◽  
John Webster ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Cell Death ◽  
Mammary Gland ◽  
Transgenic Mice ◽  
Dna Content ◽  
Caspase 3 ◽  
Transgenic Animals ◽  
Mammary Glands ◽  
Mammary Development ◽  
Igf I

We have previously demonstrated that IGFBP-5 production by mammary epithelial cells increases dramatically during involution of the mammary gland. To demonstrate a causal relationship between IGFBP-5 and cell death we created transgenic mice expressing IGFBP-5 in the mammary gland using a mammary-specific promoter, β-lactoglobulin. DNA content in the mammary glands of transgenic mice was decreased as early as day 10 of pregnancy. Histological analysis indicated reduced numbers of alveolar end buds, with decreased ductal branching. Transgenic dams produced IGFBP-5 in their milk at concentrations similar to those achieved at the end of normal lactation. Mammary cell number and milk synthesis were both decreased by approximately 50% during the first 10 days of lactation. BrdU labelling was decreased, whereas DNA ladders were increased in transgenic animals on day 1 of lactation. On day 2 postpartum, the epithelial invasion of the mammary fat pad was clearly impaired in transgenic animals. The concentrations of the pro-apoptotic molecule caspase-3 and of plasmin were both increased in transgenic animals whilst the concentrations of 2 prosurvival molecules Bcl-2 and Bcl-xLwere both decreased. In order to examine whether IGFBP-5 acts by inhibiting the survival effect of IGF-I we examined IGF receptor phosphorylation and Akt phosphorylation and showed that both were inhibited. We attempted to “rescue” the transgenic phenotype by using growth hormone to increase endogenous IGF-I concentrations or by implanting minipumps delivering an IGF-1 analogue, R3-IGF-1, which binds weakly to IGFBP-5. Growth hormone treatment failed to affect mammary development suggesting that increased concentrations of endogenous IGF-1 are insufficient to overcome the high concentrations of IGFBP-5 produced by these transgenic animals. In contrast mammary development (gland weight and DNA content) was normalised by R3-IGF-I although milk production was only partially restored. This is the first demonstration that over-expression of IGFBP-5 can lead to; impaired mammary development, increased expression of the pro-apoptotic molecule caspase-3, increased plasmin generation and decreased expression of pro-survival molecules of the Bcl-2 family. It clearly demonstrates that IGF-I is an important developmental/survival factor for the mammary gland and, furthermore, this cell death programme may be utilised in a wide variety of tissues.

scholarly journals Effects of Parity and Serum Prolactin Levels on the Incidence and Regression of DMBA-Induced Tumors in OFA hr/hr Rats

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Corina V. Sasso ◽  
Flavia E. Santiano ◽  
Constanza M. López-Fontana ◽  
Virginia Pistone-Creydt ◽  
Marcelo E. Ezquer ◽  
...  
Keyword(s):  
Hormone Receptors ◽  
Mammary Development ◽  
Serum Prolactin ◽  
Mammary Tissue ◽  
Mammary Cells ◽  
Induced Tumors ◽  
Alpha Receptors ◽  
Pregnancy And Lactation ◽  
Low Levels ◽  
Group Serum

Prolactin (PRL) is a key player in the development of mammary cancer. We studied the effects of parity or hyperprolactinemia on mammary carcinogenesis in OFA hr/hr treated with 7,12-dimethylbenzanthracene. They were divided into three groups: nulliparous (Null), primiparous (PL, after pregnancy and lactation), and hyperprolactinemic rats (I, implanted in the arcuate nucleus with 17β-estradiol). The tumor incidence was similar in the three groups. However, a higher percentage of regressing tumors was evident in the PL group. Serum PRL, mammary development, and mammaryβ-casein content were higher in I rats compared to Null. The expression of hormone receptors was similar in the different groups. However, mammary tissue from PL rats bearing tumors had increased expression of PRL and estrogen alpha receptors compared to rats free of tumors. Our results suggest that serum PRL levels do not have relevance on the incidence of tumors, probably because the low levels of PRL in OFA rats are not further decreased by PL like in other strains. However, supraphysiological levels of PRL affect carcinogenesis. PL induces regression of the tumors due to the differentiation produced on the mammary cells. Alterations in the expression of hormonal receptors may be involved in progression and regression of tumors.

THE INFLUENCE OF RELAXIN ON MAMMARY GLAND DEVELOPMENT IN GUINEA-PIGS AND RABBITS

1952 ◽  
Vol 8 (4) ◽  
pp. 336-NP ◽  
Author(s):  
FERN A. GARRETT ◽  
R. V. TALMAGE
Keyword(s):  
Guinea Pigs ◽  
Mammary Gland Development ◽  
Normal Development ◽  
Mammary Glands ◽  
Mammary Development ◽  
Mammary Tissue ◽  
Total Treatment ◽  
Per Se ◽  
Duct Development ◽  
Gland Development

An attempt has been made to determine the influence of relaxin on the early development of the mammary glands in rabbits and guinea-pigs. Spayed females of both species were treated with α-oestradiol and an extract containing relaxin, after a preliminary course of the steroid alone. In all cases the total treatment was limited to 20 days. Animals given only oestradiol served as controls. While the data presented are insufficient to substantiate without doubt an influence of relaxin per se on the development of the mammary tissue, they indicate that it enhances mammary development. In the guinea-pig this was in the form of a general growth stimulus; in the rabbit it appeared to consist of a transfer of emphasis from primary duct development to that of the entire duct system of the gland. The conclusion drawn from this study is that relaxin acts as a potentiator of oestrogen, working with the latter to produce greater and more normal development of the mammary glands.

scholarly journals 431 Increasing IGF-1 concentrations in late pregnancy stimulates mammary development of gilts

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 137-137
Author(s):  
Chantal Farmer ◽  
Pieter Langendijk
Keyword(s):  
Dry Matter ◽  
Late Pregnancy ◽  
Mammary Glands ◽  
Mammary Development ◽  
Sterile Water ◽  
Tissue Composition ◽  
Blood Concentrations ◽  
Blood Samples ◽  
Dna And Rna ◽  
Porcine Somatotropin

Abstract The goal of this project was to determine if increasing insulin-like growth factor-1 (IGF-1) concentrations in late pregnancy can stimulate mammogenesis in gilts. Yorkshire x Landrace gilts (196.2 ± 6.2 kg BW on day 89 of gestation) were separated in two groups: 1) controls (CTL, n = 17) injected with sterile water, and 2) porcine somatotropin-treated (pST, n = 20) injected daily with 5 mg of pST (Reporcin®) from days 90 to 109 of gestation. Gilts were slaughtered on day 110 to collect mammary glands and blood samples were obtained on days 89, 96, 103 and 109 of gestation. Treated gilts gained more BW (P &lt; 0.05) and lost more backfat (P &lt; 0.05) than CTL gilts during treatment. There was a treatment x day effect (P &lt; 0.01) on IGF-1, glucose and urea concentrations in blood. Concentrations of IGF-1 increased fourfold (P &lt; 0.01) in pST compared with CTL gilts on days 96, 103 and 109 of gestation. Insulin values were also greater on days 96 (P &lt; 0.01) and 103 (P = 0.01), and tended to be greater (P &lt; 0.10) on day 109 of gestation in pST gilts. Glucose was greater in pST than CTL gilts on days 96 (P &lt; 0.01), 103 (P &lt; 0.01) and 109 (P = 0.01). Injections of pST did not affect weight of mammary extraparenchyma (P &gt; 0.10) but increased mammary parenchymal mass (1922.2 vs 1576.1 ± 123.9 g, P &lt; 0.05). Mammary parenchyma contained more (P &lt; 0.05) protein, DNA and RNA and less fat (P &lt; 0.05) and dry matter (P &lt; 0.01) in pST than CTL gilts. These findings demonstrate that increasing circulating IGF-1 in late-pregnant gilts can stimulate mammary development both in terms of total parenchymal mass and of parenchymal tissue composition.

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