Localized mammary gland changes in milk composition and venous blood metabolite concentrations result from sterile subclinical mastitis.

Autor: Gammariello CS; Department of Animal Sciences, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691., Hanson J; Department of Animal Sciences, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691., Relling AE; Department of Animal Sciences, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691., Oliveira MXS; Department of Animal Sciences, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691., Sipka AS; Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853., Enger KM; Department of Animal Sciences, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691., Enger BD; Department of Animal Sciences, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH 44691. Electronic address: enger.5@osu.edu.
Jazyk: angličtina
Zdroj: Journal of dairy science [J Dairy Sci] 2024 Aug; Vol. 107 (8), pp. 6148-6160. Date of Electronic Publication: 2024 Apr 11.
DOI: 10.3168/jds.2023-24044
Abstrakt: Subclinical mastitis reduces milk yield and elicits undesirable changes in milk composition, but the mechanisms resulting in reduced milk production in affected mammary glands are incompletely understood. This study investigated the effects of sterile inflammation on mammary gland metabolism by assessing changes in milk and venous blood composition. Mid-lactation primiparous Holstein cows (n = 4) had udder halves randomly allocated to treatments; quarters of 1 udder half were infused with 2 billion cfu of formalin-fixed Staphylococcus aureus (FX-STAPH) and quarters of the opposite udder half were infused with saline (SAL). Blood samples were collected from the right and left subcutaneous abdominal veins in 2.6 h intervals until 40 h postchallenge and analyzed for blood gas and metabolite concentrations. Milk from FX-STAPH udder halves had significantly increased SCS by the first milking at 8 h postchallenge. By 16 h postchallenge, FX-STAPH udder halves had increased concentrations of protein and lactate and lower lactose concentrations than SAL udder halves. Milk fat concentrations, milk yields, ECM yields, and the ferric reducing antioxidant power of milk were not significantly different between SAL and FX-STAPH udder halves. Venous blood of FX-STAPH halves had marginally greater concentrations of saturated O 2 , partial pressures of O 2 , and glucose concentrations than SAL halves. Conversely, total and partial pressures of CO 2 did not differ between udder half treatments, suggesting a shift in local metabolite utilization in FX-STAPH udder halves. These results indicate that changes in milk composition resulting from mastitis are accompanied by changes in some key blood metabolite concentrations. The shift in venous blood metabolite concentrations, along with the marked increase in milk lactate, suggests that local mammary tissue or recruited immune cells, or both, alter metabolite usage in mammary tissues. Future studies are needed to quantify the uptake of key milk precursors during mastitis.
(© 2024, The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)
Databáze: MEDLINE
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