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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Dairy Forage Research » Research » Publications at this Location » Publication #434566
Research Project: Forage and Feed Characteristics on Performance, Feed Efficiency, Environmental Impact, and Farm Nutrient Cycling of Dairy Production Systems

Location: Dairy Forage Research

Title: Impact of dietary essential amino acid balance on pregnancy success and uterine transcriptome in lactating dairy cows

Author
item SOSA, FROYLAN - University Of Wisconsin
item CASTRO, BRIZA - University Of Wisconsin
item French, Elizabeth
item McClure, Jennifer
item ARRIOLA APELO, SEBASTIAN - University Of Wisconsin
item ORTEGA, SOFIA - University Of Wisconsin

Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/7/2026
Publication Date: 7/20/2026
Citation: Sosa, F., Castro, B., French, E.A., Mcclure, J.C., Arriola Apelo, S.I., Ortega, S. 2026. Impact of dietary essential amino acid balance on pregnancy success and uterine transcriptome in lactating dairy cows. Society for the Study of Reproduction Annual Meeting. Society for the Study of Reproduction.

Interpretive Summary:

Technical Abstract: Mammals cannot synthesize essential amino acids (AAs) de novo and rely on dietary intake to support critical biological functions, including reproduction. Because AAs support key metabolic pathways during early pregnancy, we hypothesized that balancing essential AAs in the diet of lactating dairy cows would improve pregnancy outcomes and modulate uterine gene expression. Eighty-five multiparous Holstein cows were assigned at calving to either a high rumen degradable protein diet (HRDP; 12% RDP, 3.8% digestible rumen undegradable protein) or an amino acid-balanced diet (BAA; 10.2% RDP with increased digestible rumen undegradable protein, balanced for arginine, histidine, leucine, isoleucine, lysine, and methionine). Diets were isoenergetic, formulated to meet lactation requirements, and fed from calving until 30 days post-artificial insemination. Pregnancy was achieved by using a standard ovulation synchronization protocol followed by timed artificial insemination and confirmed by ultrasonography at day 30. Endometrial cytology samples collected by uterine cytobrush one week before timed artificial insemination were used for transcriptomic analysis. Pregnancy rates did not differ between diets (HRDP: 41.8 ± 7.8% vs BAA: 36.9 ± 7.4%; P = 0.65). Transcriptomic analysis revealed 57 differentially expressed genes (DEGs), with 30 upregulated and 27 downregulated in BAA cows. Upregulated genes included immune- and inflammation-related genes (S100A8, DEFB4A, IL17A, IL36A), genes involved in lipid metabolism (ALOX12B, CYP2W1), oxidative stress response (GSTA1), and calcium signaling (TRPA1, CAMK2A). Downregulated genes included CITED2, a transcriptional regulator of placental development, as well as reproduction-associated genes PTGFR, CXCL14, C4BPA, and SALL4, a key regulator of embryonic stemness. Together, these findings demonstrate that balancing AAs remodeled the uterine transcriptome across immune, metabolic, and reproductive gene networks. These results highlight the sensitivity of the endometrial environment to maternal nutritional status and suggest that further optimization of the timing, duration, and specific AAs targets of dietary balancing strategies may be necessary to translate molecular endometrial responses into improved reproductive outcomes.