Effect of continuous milking and bovine somatotropin supplementation on mammary epithelial cell turnover

E. L. Annen, A. C. Fitzgerald, P. C. Gentry, M. A. McGuire, A. V. Capuco, L. H. Baumgard, Robert J Collier

Research output: Contribution to journalArticle

37 Citations (Scopus)

Abstract

Objectives were to determine effects of continuous milking (CM) and bovine somatotropin (bST) administration on 1) mammary epithelial cell (MEC) proliferation, apoptosis, and ultrastructure during late gestation and early lactation, 2) expression of genes associated with proliferation, and apoptosis in mammary epithelial cells, and 3) milk yield and composition. Secondgestation, first dry-period cows were randomly assigned to either continuous bST throughout late gestation and early lactation (+bST; n = 4) or no bST (-bST; n = 4) administration. Within each animal, udder halves were randomly assigned to CM or a 60-d dry period (control) treatment. Daily milk yield and weekly milk composition were measured during the last 60 d of gestation in CM halves and from 1 to 30 d postpartum for both halves. Mammary biopsies were obtained at -20 ± 7, -8 ± 3, +1 ± 0, +7 ± 0, and +20 ± 0 d (mean ± standard error) relative to parturition. Prepartum half-udder milk yield was greater in +bST cows than in -bST cows (9.9 vs. 8.2 kg/d) and postpartum half-udder milk yields were dramatically reduced in CM halves compared with control halves (10.6 vs. 22.2 kg/d), regardless of bST treatment. Proliferation of MEC was reduced in CM halves at -8 d (2.7 vs. 5.4%). Apoptosis of MEC was elevated during early lactation for d +1 and +7 in control halves, but was only increased at d +1 in CM halves. Turnover of MEC was not affected by bST. Ultrastructure data indicated complete involution of the control half and lactation maintenance in CM glands (d -20). By d -8, control tissue contained alveoli in an immature secretory state, but CM tissue contained both lactating and immature alveoli. Postpartum ultrastructure parameters were similar between halves until d 20 when control tissue was composed of a homogeneous population of lactating alveoli, but CM tissue contained lactating, engorged, and resting alveoli. Expression of CCAAT/enhancer binding protein-β (CEBP-β), cyclin D1, and bcl 2 were up-regulated during late gestation, but did not differ between control and CM halves. Expression of α-lactalbumin was increased in CM halves during late gestation, but was not different in CM and control tissue after parturition. Other genes evaluated (bax, insulin-like growth factor binding protein 5, ATPbinding cassette 1, and p27) were not differentially expressed at any timepoints evaluated. Results indicate that CM reduced subsequent half-udder milk yield in primiparous cows through altered MEC turnover and secretory capacity. Negative effects of CM on the subsequent lactation were not alleviated by bST supplementation.

Original languageEnglish (US)
Pages (from-to)165-183
Number of pages19
JournalJournal of Dairy Science
Volume90
Issue number1
StatePublished - Jan 2007

Fingerprint

milking
somatotropin
breasts
Breast
epithelial cells
Epithelial Cells
Animal Mammary Glands
Milk
Lactation
Pregnancy
Postpartum Period
milk yield
udders
pregnancy
Apoptosis
early lactation
cows
dry period (lactation)
ultrastructure
apoptosis

Keywords

  • Bovine somatotropin
  • Continuous lactation
  • Gene expression
  • Half udder

ASJC Scopus subject areas

  • Animal Science and Zoology
  • veterinary(all)
  • Food Science

Cite this

Annen, E. L., Fitzgerald, A. C., Gentry, P. C., McGuire, M. A., Capuco, A. V., Baumgard, L. H., & Collier, R. J. (2007). Effect of continuous milking and bovine somatotropin supplementation on mammary epithelial cell turnover. Journal of Dairy Science, 90(1), 165-183.

Effect of continuous milking and bovine somatotropin supplementation on mammary epithelial cell turnover. / Annen, E. L.; Fitzgerald, A. C.; Gentry, P. C.; McGuire, M. A.; Capuco, A. V.; Baumgard, L. H.; Collier, Robert J.

In: Journal of Dairy Science, Vol. 90, No. 1, 01.2007, p. 165-183.

Research output: Contribution to journalArticle

Annen, EL, Fitzgerald, AC, Gentry, PC, McGuire, MA, Capuco, AV, Baumgard, LH & Collier, RJ 2007, 'Effect of continuous milking and bovine somatotropin supplementation on mammary epithelial cell turnover', Journal of Dairy Science, vol. 90, no. 1, pp. 165-183.
Annen EL, Fitzgerald AC, Gentry PC, McGuire MA, Capuco AV, Baumgard LH et al. Effect of continuous milking and bovine somatotropin supplementation on mammary epithelial cell turnover. Journal of Dairy Science. 2007 Jan;90(1):165-183.
Annen, E. L. ; Fitzgerald, A. C. ; Gentry, P. C. ; McGuire, M. A. ; Capuco, A. V. ; Baumgard, L. H. ; Collier, Robert J. / Effect of continuous milking and bovine somatotropin supplementation on mammary epithelial cell turnover. In: Journal of Dairy Science. 2007 ; Vol. 90, No. 1. pp. 165-183.
@article{bef2edebc9bd473a9c489c8f4cb3cda1,
title = "Effect of continuous milking and bovine somatotropin supplementation on mammary epithelial cell turnover",
abstract = "Objectives were to determine effects of continuous milking (CM) and bovine somatotropin (bST) administration on 1) mammary epithelial cell (MEC) proliferation, apoptosis, and ultrastructure during late gestation and early lactation, 2) expression of genes associated with proliferation, and apoptosis in mammary epithelial cells, and 3) milk yield and composition. Secondgestation, first dry-period cows were randomly assigned to either continuous bST throughout late gestation and early lactation (+bST; n = 4) or no bST (-bST; n = 4) administration. Within each animal, udder halves were randomly assigned to CM or a 60-d dry period (control) treatment. Daily milk yield and weekly milk composition were measured during the last 60 d of gestation in CM halves and from 1 to 30 d postpartum for both halves. Mammary biopsies were obtained at -20 ± 7, -8 ± 3, +1 ± 0, +7 ± 0, and +20 ± 0 d (mean ± standard error) relative to parturition. Prepartum half-udder milk yield was greater in +bST cows than in -bST cows (9.9 vs. 8.2 kg/d) and postpartum half-udder milk yields were dramatically reduced in CM halves compared with control halves (10.6 vs. 22.2 kg/d), regardless of bST treatment. Proliferation of MEC was reduced in CM halves at -8 d (2.7 vs. 5.4{\%}). Apoptosis of MEC was elevated during early lactation for d +1 and +7 in control halves, but was only increased at d +1 in CM halves. Turnover of MEC was not affected by bST. Ultrastructure data indicated complete involution of the control half and lactation maintenance in CM glands (d -20). By d -8, control tissue contained alveoli in an immature secretory state, but CM tissue contained both lactating and immature alveoli. Postpartum ultrastructure parameters were similar between halves until d 20 when control tissue was composed of a homogeneous population of lactating alveoli, but CM tissue contained lactating, engorged, and resting alveoli. Expression of CCAAT/enhancer binding protein-β (CEBP-β), cyclin D1, and bcl 2 were up-regulated during late gestation, but did not differ between control and CM halves. Expression of α-lactalbumin was increased in CM halves during late gestation, but was not different in CM and control tissue after parturition. Other genes evaluated (bax, insulin-like growth factor binding protein 5, ATPbinding cassette 1, and p27) were not differentially expressed at any timepoints evaluated. Results indicate that CM reduced subsequent half-udder milk yield in primiparous cows through altered MEC turnover and secretory capacity. Negative effects of CM on the subsequent lactation were not alleviated by bST supplementation.",
keywords = "Bovine somatotropin, Continuous lactation, Gene expression, Half udder",
author = "Annen, {E. L.} and Fitzgerald, {A. C.} and Gentry, {P. C.} and McGuire, {M. A.} and Capuco, {A. V.} and Baumgard, {L. H.} and Collier, {Robert J}",
year = "2007",
month = "1",
language = "English (US)",
volume = "90",
pages = "165--183",
journal = "Journal of Dairy Science",
issn = "0022-0302",
publisher = "Elsevier Limited",
number = "1",

}

TY - JOUR

T1 - Effect of continuous milking and bovine somatotropin supplementation on mammary epithelial cell turnover

AU - Annen, E. L.

AU - Fitzgerald, A. C.

AU - Gentry, P. C.

AU - McGuire, M. A.

AU - Capuco, A. V.

AU - Baumgard, L. H.

AU - Collier, Robert J

PY - 2007/1

Y1 - 2007/1

N2 - Objectives were to determine effects of continuous milking (CM) and bovine somatotropin (bST) administration on 1) mammary epithelial cell (MEC) proliferation, apoptosis, and ultrastructure during late gestation and early lactation, 2) expression of genes associated with proliferation, and apoptosis in mammary epithelial cells, and 3) milk yield and composition. Secondgestation, first dry-period cows were randomly assigned to either continuous bST throughout late gestation and early lactation (+bST; n = 4) or no bST (-bST; n = 4) administration. Within each animal, udder halves were randomly assigned to CM or a 60-d dry period (control) treatment. Daily milk yield and weekly milk composition were measured during the last 60 d of gestation in CM halves and from 1 to 30 d postpartum for both halves. Mammary biopsies were obtained at -20 ± 7, -8 ± 3, +1 ± 0, +7 ± 0, and +20 ± 0 d (mean ± standard error) relative to parturition. Prepartum half-udder milk yield was greater in +bST cows than in -bST cows (9.9 vs. 8.2 kg/d) and postpartum half-udder milk yields were dramatically reduced in CM halves compared with control halves (10.6 vs. 22.2 kg/d), regardless of bST treatment. Proliferation of MEC was reduced in CM halves at -8 d (2.7 vs. 5.4%). Apoptosis of MEC was elevated during early lactation for d +1 and +7 in control halves, but was only increased at d +1 in CM halves. Turnover of MEC was not affected by bST. Ultrastructure data indicated complete involution of the control half and lactation maintenance in CM glands (d -20). By d -8, control tissue contained alveoli in an immature secretory state, but CM tissue contained both lactating and immature alveoli. Postpartum ultrastructure parameters were similar between halves until d 20 when control tissue was composed of a homogeneous population of lactating alveoli, but CM tissue contained lactating, engorged, and resting alveoli. Expression of CCAAT/enhancer binding protein-β (CEBP-β), cyclin D1, and bcl 2 were up-regulated during late gestation, but did not differ between control and CM halves. Expression of α-lactalbumin was increased in CM halves during late gestation, but was not different in CM and control tissue after parturition. Other genes evaluated (bax, insulin-like growth factor binding protein 5, ATPbinding cassette 1, and p27) were not differentially expressed at any timepoints evaluated. Results indicate that CM reduced subsequent half-udder milk yield in primiparous cows through altered MEC turnover and secretory capacity. Negative effects of CM on the subsequent lactation were not alleviated by bST supplementation.

AB - Objectives were to determine effects of continuous milking (CM) and bovine somatotropin (bST) administration on 1) mammary epithelial cell (MEC) proliferation, apoptosis, and ultrastructure during late gestation and early lactation, 2) expression of genes associated with proliferation, and apoptosis in mammary epithelial cells, and 3) milk yield and composition. Secondgestation, first dry-period cows were randomly assigned to either continuous bST throughout late gestation and early lactation (+bST; n = 4) or no bST (-bST; n = 4) administration. Within each animal, udder halves were randomly assigned to CM or a 60-d dry period (control) treatment. Daily milk yield and weekly milk composition were measured during the last 60 d of gestation in CM halves and from 1 to 30 d postpartum for both halves. Mammary biopsies were obtained at -20 ± 7, -8 ± 3, +1 ± 0, +7 ± 0, and +20 ± 0 d (mean ± standard error) relative to parturition. Prepartum half-udder milk yield was greater in +bST cows than in -bST cows (9.9 vs. 8.2 kg/d) and postpartum half-udder milk yields were dramatically reduced in CM halves compared with control halves (10.6 vs. 22.2 kg/d), regardless of bST treatment. Proliferation of MEC was reduced in CM halves at -8 d (2.7 vs. 5.4%). Apoptosis of MEC was elevated during early lactation for d +1 and +7 in control halves, but was only increased at d +1 in CM halves. Turnover of MEC was not affected by bST. Ultrastructure data indicated complete involution of the control half and lactation maintenance in CM glands (d -20). By d -8, control tissue contained alveoli in an immature secretory state, but CM tissue contained both lactating and immature alveoli. Postpartum ultrastructure parameters were similar between halves until d 20 when control tissue was composed of a homogeneous population of lactating alveoli, but CM tissue contained lactating, engorged, and resting alveoli. Expression of CCAAT/enhancer binding protein-β (CEBP-β), cyclin D1, and bcl 2 were up-regulated during late gestation, but did not differ between control and CM halves. Expression of α-lactalbumin was increased in CM halves during late gestation, but was not different in CM and control tissue after parturition. Other genes evaluated (bax, insulin-like growth factor binding protein 5, ATPbinding cassette 1, and p27) were not differentially expressed at any timepoints evaluated. Results indicate that CM reduced subsequent half-udder milk yield in primiparous cows through altered MEC turnover and secretory capacity. Negative effects of CM on the subsequent lactation were not alleviated by bST supplementation.

KW - Bovine somatotropin

KW - Continuous lactation

KW - Gene expression

KW - Half udder

UR - http://www.scopus.com/inward/record.url?scp=34547293757&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34547293757&partnerID=8YFLogxK

M3 - Article

C2 - 17183085

AN - SCOPUS:34547293757

VL - 90

SP - 165

EP - 183

JO - Journal of Dairy Science

JF - Journal of Dairy Science

SN - 0022-0302

IS - 1

ER -