Cyclical heat stress during lactation influences the microstructure of the bovine mammary gland

Simple item page
dc.contributor.authorPerez-Hernandez, G.en
dc.contributor.authorEllett, Mark D.en
dc.contributor.authorBanda, L. J.en
dc.contributor.authorDougherty, D.en
dc.contributor.authorParsons, Catherine L. M.en
dc.contributor.authorLengi, A. J.en
dc.contributor.authorDaniels, Kristy M.en
dc.contributor.authorCorl, Benjamin A.en
dc.date.accessioned2025-02-07T18:28:25Zen
dc.date.available2025-02-07T18:28:25Zen
dc.date.issued2024-05-31en
dc.description.abstractThis study aimed to evaluate the effect of heat stress on mammary epithelial cell (MEC) losses into milk, secretory mammary tissue structure, and mammary epithelial cell activity. Sixteen multiparous Holstein cows (632 ± 12 kg BW) approximately 100 DIM housed in climate-controlled rooms were paired by BW and randomly allocated to one of 2 treatments, heat stress (HS) or pair-feeding thermoneutral (PFTN) using 2 cohorts. Each cohort was subjected to 2 periods of 4 d each. In period 1, both treatments had ad libitum access to a common TMR and were exposed to a controlled daily temperature-humidity index (THI) of 64. In period 2, HS cows were exposed to controlled cyclical heat stress (THI: 74–80), while PFTN cows remained at 64 THI and daily DMI was matched to that of the HS cows. Cows were milked twice daily, and milk yield was recorded at each milking. Individual milk samples on the last day of each period were used to quantify MEC losses by flow cytometry using butyrophilin as a cell surface marker. On the final day of period 2, individual bovine mammary tissue samples were obtained for histomorphology analysis, assessment of protein abundance, and evaluation of gene expression of targets associated with cellular capacity for milk and milk component synthesis, heat response, cellular proliferation, and autophagy. Statistical analysis was performed using the GLIMMIX procedure of SAS. Milk yield was reduced by 4.3 kg by HS (n = 7) compared with PFTN (n = 8). Independent of treatment, MEC in milk averaged 174 cells/mL (2.9% of total cells). There was no difference between HS and PFTN cows for MEC shed or concentration in milk. Alveolar area was reduced 25% by HS, and HS had 4.1 more alveoli than PFTN. The total number of nucleated MEC per area was greater in HS cows (389 ± 1.05; mean ± SE) compared with PFTN (321 ± 1.05); however, cell number per alveolus was similar between groups (25 ± 1.5 vs. 26 ± 1.4). There were no differences in relative fold expression for GLUT1, GLUT8, CSN2, CSN3, LALBA, FASN, HSPA5, and HSPA8 in HS cows compared with PFTN cows. Immunoblotting analyses showed a decrease in abundance for phosphorylated STAT5 and S6K1, and an increase in LC3 II in HS cows compared with PFTN cows. These results suggest that even if milk yield differences and histological changes occur in the bovine mammary gland after 4 d of heat exposure, MEC loss into milk, nucleated MEC number per alveolus, and gene expression of nutrient transport, milk component synthesis, and heat-stress-related targets are unaffected. In contrast, the abundance of proteins related to protein synthesis and cell survival decreased significantly, whereas proteins associated with autophagy were upregulated in HS cows compared with PFTN cows.en
dc.description.versionPublished versionen
dc.format.extentPages 8609-8628en
dc.format.extent20 page(s)en
dc.format.mimetypeapplication/pdfen
dc.identifier.doihttps://doi.org/10.3168/jds.2024-24809en
dc.identifier.eissn1525-3198en
dc.identifier.issn0022-0302en
dc.identifier.issue10en
dc.identifier.orcidCorl, Benjamin [0000-0002-6495-3279]en
dc.identifier.orcidDaniels, Kristy [0000-0002-1437-1457]en
dc.identifier.otherS0022-0302(24)00866-X (PII)en
dc.identifier.pmid38825136en
dc.identifier.urihttps://hdl.handle.net/10919/124533en
dc.identifier.volume107en
dc.language.isoenen
dc.publisherElsevieren
dc.relation.urihttps://www.ncbi.nlm.nih.gov/pubmed/38825136en
dc.rightsCreative Commons Attribution 4.0 Internationalen
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/en
dc.subjectmammary gland structureen
dc.subjectMEC loss and numberen
dc.subjectheat stressen
dc.subjectlactationen
dc.subject.meshMammary Glands, Animalen
dc.subject.meshEpithelial Cellsen
dc.subject.meshMilken
dc.subject.meshAnimalsen
dc.subject.meshCattleen
dc.subject.meshHeat-Shock Responseen
dc.subject.meshLactationen
dc.subject.meshFemaleen
dc.subject.meshHot Temperatureen
dc.titleCyclical heat stress during lactation influences the microstructure of the bovine mammary glanden
dc.title.serialJournal of Dairy Scienceen
dc.typeArticle - Refereeden
dc.type.dcmitypeTexten
dc.type.otherArticleen
dc.type.otherJournalen
dcterms.dateAccepted2024-04-19en
pubs.organisational-groupVirginia Techen
pubs.organisational-groupVirginia Tech/Agriculture & Life Sciencesen
pubs.organisational-groupVirginia Tech/Agriculture & Life Sciences/School of Animal Sciencesen
pubs.organisational-groupVirginia Tech/All T&R Facultyen
pubs.organisational-groupVirginia Tech/Agriculture & Life Sciences/CALS T&R Facultyen

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
cyclical_hs.pdf
Size:
4.36 MB
Format:
Adobe Portable Document Format
Description:
Published version
Download
License bundle
Now showing 1 - 1 of 1
Name:
license.txt
Size:
1.5 KB
Format:
Plain Text
Description:
Download

Collections

All Faculty Deposits
Scholarly Works, School of Animal Sciences