Academic Journal
The effect of increasing dietary fat concentration on mammary arteriovenous fatty acid difference and milk fat yield in Holstein cows.
| Τίτλος: | The effect of increasing dietary fat concentration on mammary arteriovenous fatty acid difference and milk fat yield in Holstein cows. |
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| Συγγραφείς: | Homan AN; Department of Animal Science, Penn State University, University Park, PA 16802., Harvatine KJ; Department of Animal Science, Penn State University, University Park, PA 16802. Electronic address: kjh182@psu.edu. |
| Πηγή: | Journal of dairy science [J Dairy Sci] 2026 Sep; Vol. 109 (9), pp. 9964-9986. Date of Electronic Publication: 2026 May 04. |
| Τύπος έκδοσης: | Journal Article |
| Γλώσσα: | English |
| Στοιχεία περιοδικού: | Publisher: American Dairy Science Association Country of Publication: United States NLM ID: 2985126R Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1525-3198 (Electronic) Linking ISSN: 00220302 NLM ISO Abbreviation: J Dairy Sci Subsets: MEDLINE |
| Imprint Name(s): | Publication: Champaign, IL : American Dairy Science Association Original Publication: Lancaster, Pa. [etc.] |
| Ιατρικοί όροι (MeSH): | Milk*/chemistry , Milk*/metabolism , Dietary Fats*/administration & dosage , Dietary Fats*/metabolism , Fatty Acids*/blood , Fatty Acids*/metabolism , Mammary Glands, Animal*/blood supply , Mammary Glands, Animal*/metabolism, Cattle/physiology ; Cattle/metabolism ; Triglycerides/blood ; Triglycerides/metabolism ; Diet/veterinary ; Animal Feed/analysis ; Fatty Acids, Nonesterified/blood ; Animals ; Female ; Lactation ; Cross-Over Studies |
| Περίληψη: | Dairy producers invest in fatty acid (FA) supplements to increase energy intake and maximize milk fat yield, but the effect of dietary fat level on mammary FA uptake and metabolism are not well described. Our objective was to characterize mammary arteriovenous (AV) difference and extraction percentage of total plasma FA, triglycerides (TG), and nonesterified FA (NEFA) at 2 levels of dietary fat. The hypothesis was that mammary AV difference of palmitic acid (16:0), stearic acid (18:0), TG, and NEFA would be greater in cows fed a higher-fat diet compared with a lower-fat diet due to increased arterial concentration and therefore substrate availability of these FA. The secondary hypothesis was that the mammary extraction percentage of FA would increase as arterial concentration of FA increased, suggesting a concentration-dependent mechanism of uptake. Nine multiparous Holstein cows were arranged in a crossover design with 14-d periods. Treatments were a lower-fat diet (LF; 2.7% FA) or a higher-fat diet that contained roasted soybeans, whole cottonseed, and a prilled FA supplement (HF; 4.9% FA). Data were analyzed in a mixed model that included the random effect of cow and period and fixed effect of treatment. For plasma analysis, the fixed effect of time and interaction of treatment and time were added to the model. We found no effect of treatment on milk or milk protein yield. Feeding the HF diet increased milk fat percentage by 0.26 units and milk fat yield by 88 g/d, with an increase in the yield of >16 C preformed and 16 C mixed source FA. The HF diet increased the proportion of 16:0, 18:0, and linoleic acid (18:2n-6) in both arterial and venous plasma FA and decreased the proportion of oleic (18:1 cis[c]9) and α-linolenic (18:3n-3) acid. It also increased total arterial FA concentration by 21%. Approximately half of the increase in arterial FA was due to 18:2n-6 (+232 mg/L), whereas smaller increases were also observed for 16:0, 18:0, 18:1c9, and 18:3n-3. We observed a treatment by time interaction for the AV difference of total FA and 18:1c9 and a tendency for an interaction for 18:0 and 18:2n-6, where there was a greater AV difference between treatments at 1600 h compared with other time points. The HF diet also increased the AV difference of 16:0, but there was no interaction of treatment and time. We found no treatment or treatment by time interactions for AV difference of TG and NEFA. There was an interaction of treatment and milking time for milk fat percent that aligned with total plasma FA AV data, where the difference between HF and LF was greater at the evening milking compared with the morning. In conclusion, increasing dietary fat increased milk fat yield through an increase in total plasma FA concentration and an increase in AV difference of specific FA with variation in the response across the day. (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/).) |
| Contributed Indexing: | Keywords: fatty acid; lactation; lipid; nutrition |
| Substance Nomenclature: | 0 (Dietary Fats) 0 (Fatty Acids) 0 (Triglycerides) 0 (Fatty Acids, Nonesterified) |
| Entry Date(s): | Date Created: 20260507 Date Completed: 20260828 Latest Revision: 20260828 |
| Update Code: | 20260829 |
| DOI: | 10.3168/jds.2026-28324 |
| PMID: | 42092543 |
| Βάση Δεδομένων: | MEDLINE |
| ISSN: | 1525-3198 |
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| DOI: | 10.3168/jds.2026-28324 |