HARNESSING THE LIPOGENIC POTENTIAL OF OLEIC ACID TO MINIMIZE BODY WEIGHT LOSS AND MAXIMIZE LACTATION PERFORMANCE OF PERIPARTURIENT DAIRY COWS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: ACTIVE
• Funding Source: AFRI COMPETITIVE GRANT
• Reporting Frequency: Annual
• Accession No.: 1024201
• Grant No.: 2021-67015-33386
• Cumulative Award Amt.: $500,000.00
• Proposal No.: 2020-02676
• Project Start Date: Jan 1, 2021
• Project End Date: Dec 31, 2025
• Grant Year: 2021
• Program Code: [A1231]- Animal Health and Production and Animal Products: Improved Nutritional Performance, Growth, and Lactation of Animals

Recipient Organization
MICHIGAN STATE UNIV
(N/A)
EAST LANSING,MI 48824

Performing Department
ANIMAL SCIENCE

Non Technical Summary
Over the last decade increased emphasis has been placed on improving our understanding of ruminant lipid digestion andmetabolism in order to enhance dairy cow productivity, animal health, and the quality of dairy products for consumers. Our projects focus is on the period around calving and the initiation of milk production (the periparturient period). This period is challenging for dairy cows as energy and nutrient intake do not meet requirements for maintenance, growth, and milk synthesis. As a result, cows experience negative energy balance during early lactation that is further aggravated by reduced feed intake. Cows successfully adapt to negative energy balance when the release of fatty acids from body fat is limited to concentrations that can be fully used for energy needs. Excessive mobilization of body reserves around parturition are associated with poor lactation performance and increased incidence of diseases. Our long-term goal is to develop strategies for feeding periparturient dairy cows to increase the yield and efficiency of milk production while optimizing body condition and health. Our objective of this project is to determine the role of dietary oleic acid on adipose tissue metabolism, energy partitioning, and milk production of periparturient dairy cows. Based on our preliminary data, we hypothesize that dietary oleic acid regulates lipogenesis and insulin sensitivity in adipose tissue of periparturient dairy cows which will minimize body weight loss and maximize lactation performance. We will use in vitro and in vivo studies to test our hypothesis.We will determine how oleic acid exerts lipogenic and insulin sensitizing effects in adipose tissue and how dietary supplementation of oleic acid effects milk production and body weight loss across the periparturient period.Collectively, these outcomes will enable us to positively impact dairy cattle performance, production efficiency, and farm income by gaining insight on strategies to increase nutrient use for milk synthesis.Our original research findings will translate into immediate application on US dairy farms, and thus advance the competitiveness and sustainability of the dairy industry.

Animal Health Component

30%

Research Effort Categories

Basic

70%

Applied

30%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
302	3410	1010	60%
305	3410	1030	20%
307	3410	1010	20%

Knowledge Area
302 - Nutrient Utilization in Animals; 305 - Animal Physiological Processes; 307 - Animal Management Systems;

Subject Of Investigation
3410 - Dairy cattle, live animal;

Field Of Science
1030 - Cellular biology; 1010 - Nutrition and metabolism;

Keywords

adipose metabolism

dairy cow

energy partitioning

milk production

oleic acid

Goals / Objectives
The early postpartum period is metabolically challenging for dairy cows as energy and nutrient intake do not meet requirements for maintenance, growth, and milk synthesis. The development of many periparturient cow disorders result when cows fail to adapt physiologically to the high-energy and nutrient demands needed for the onset of copious milk synthesis and secretion. As a result, cows experience negative energy balanceduring early lactation that is further aggravated by reduced feed intake around the time of parturition. Energy requirements that are not met by the diet must then rely on tissue energy reserves. Cows successfully adapt to negative energy balance when the release of fatty acids is limited to concentrations that can be fully metabolized for energy needs.Changes in the extent and balance of lipogenesis and lipolysis in adipose tissue ultimately determines the intensity and duration of body weight loss during the periparturient period. Excessive mobilization of body reserves is associated with metabolic diseases that lead to poor production and health. Even in the absence of metabolic diseases, excessive fatty acid mobilization leads to excessive body weight loss and suboptimal lactational and reproductive performance that negatively affect the profitability of the dairy enterprise.Therefore, nutritional strategies that ameliorate negative energy balance and enhance nutrient supply may improve lactation performance and health of early postpartum cows.Ourlong-term goalis to develop effective strategies for feeding periparturientdairy cows to increase the yield and efficiency of milk production while optimizing body condition, thereby maximizing production, reproduction, health, and farm profitability.Nutrition of the dairy cow is the major factor that impacts rumen lipid metabolism and consequently the supply of fatty acidsavailable to the animal.Based on recent studies by our group we are increasing our understanding on the effects of specific fatty acids on metabolism and animal responses. Our preliminary results suggest thatcis-9 C18:1 (oleic acid) can alter fatty acidtrafficking and insulin sensitivity in adipose tissue and nutrient partitioning during the early postpartum period and established lactation. However, because mechanisms underlying oleic acid responses and the timing of oleic acid supplementation are not understood, opportunities to utilize this fatty acidin dairy cow diets on farms is suboptimal. Thus, we see acritical needto elucidate mechanisms ofhowandwhenoleic acid impacts adipose tissue metabolism and its effects on body weight loss and lactation performance during the periparturient period; this may allow for targeted feeding of this fatty acidacross different stages of lactation according to the metabolic priority of dairy cows and management needs.This projects objectives areto determine the role of oleic acid in fatty acidtrafficking and insulin sensitivity of adipose tissue, and energy partitioning, body weight loss, and milk production of periparturient dairy cows. Specifically we will:1. Determine how oleic acid enhances lipogenic responses and insulin sensitivity in bovine adipocytes.2. Determine the effects of periparturientsupplementation of oleic acid onmilk production, body weight loss, and adipose tissue insulin sensitivity and lipogenic potential.Ourcentral hypothesis,based upon strong preliminary data, is that oleic acid regulates lipogenesis and insulin sensitivity inadipose tissuethereby allowing for improved nutrient utilization for maximal milk production while minimizing body weight loss and metabolic health disorders.Ourrationaleis that the successful completion of this project will allow for the development of precision feeding programs to facilitate improved energy balance and reduced lipid mobilization in the critical periparturient period that will ultimately minimize health disorders and improve milk yield and efficiency of nutrient utilization.Our proposed project isinnovativebecause it employs a combination of in vivo nutrition studies throughout the periparturient period along with in vitro and ex vivo culture systems to investigate the impact and mechanisms of oliec acid on adipocyte fatty acid metabolism. Collectively, these outcomes will enable us topositively impactdairy cattle performance, production efficiency, and farm income andwill translate into immediate application on US dairy farms, and thus advance the competitiveness and sustainability of the dairy industry.

Project Methods
Our aims will be addressed using complementaryin vitroandin vivoexperiments. The Institutional Animal Care and Use Committee at Michigan State University will approve all experimental procedures. All cows will be from the Michigan State University Dairy Cattle Teaching and Research Center.The design and implementation of in vitro and in vivo studies will be based on our previous work atMichigan State University.Our in vitro studieswill determine the direct effect of oleic acid on adipocyte lipogenic responses and insulin sensitivity by using primary preadipocytes from omental and subcutaneous adipose tissue.We will supplement adipocytes during different stages of differentiation witholeic acidand mixtures of oleic acid with other fatty acids.We will evaluate the effects of oleic acid during adipogenesis, lipogenesis, and throughout the entire differentiation process, andharvest adipocytes and culture media. Lipogenic, lipoytic, and sensitivity to insulinresponses will be quantified using different approaches. Allcellular, biochemical, and molecular techniquesare routinely used in our laboratories.Experiments will include adipocytes from 8 animals. To assure the repeatability and reproducibility of our results, we will run each assay in triplicate. Variables will be analyzed by ANOVA (JMP software, SAS Inst.). Significance will be set at P<0.05.Our in vivo studieswill determinethe effects of periparturient supplementation of oleic acid on milk production, body weight loss, and adipose tissue insulin sensitivity and lipogenic potential of dairy cows.Fifty-two multiparous Holstein cows will be used in a randomized complete block design experiment with a 2x2 factorial arrangement of treatmentswith 13 cows per treatment.Treatment diets containing supplemental oleic acid will be fed in both the close-up and fresh periods. During the close-up period (-24 d to calving) cows will assigned to either a control diet containing no supplemental oleic acid or the control diet supplemented with a calcium-saltof oleic acid. During the fresh period (1-24 days in milk) cows will be assigned to either a control diet containing no supplemental oleic acidor a calcium-salt of oleic acidin a 2x2 factorial arrangement of treatments considering the diet that they received during the close-up period.A common lactation diet will be fed from 25 to 70 daysin milk to evaluate potential carryover effects of the treatment diets.Samples and data will be collected throughout the study periods for feed intake, nutrient digestibility, yield of milk and milk components, changes in body weight and body condition, and blood hormones and metabolites.On day −25 relative to calving (prior to start of close-up treatment diets), day −10 relative to calving, and 14 days in milk biopsies of subcutaneous adipose tissue will be obtained from the right paralumbar fossaWe will evaluate the effects of oleic acid on fatty acidtrafficking and insulin responses of explants from the subcutaneous adiposebiopsies. We use this approach, instead of intravenous glucose tolerance tests and surrogate indices, because systemic measures have limited diagnostic value due to large variation in insulin secretion and glucose partitioning during the periparturient period.All data will be analyzed as a block design using the MIXED procedure of SAS v.9.4 (SAS Institute). Data will be analyzed separately for the close-up, fresh, and carryover periods, as well as the interactions between treatment, period, and time. The statistical model will include the fixed effect of treatment, time, and their interaction, and the random effect of block, cow within block, and Julian date. Normality of the residuals will be checked with normal probability and box plots and homogeneity of variances with plots of residuals vs. predicted values. Significance will be declared at P ≤ 0.05 for main effects and P ≤ 0.10 for interactions.

Progress 01/01/24 to 12/31/24

Outputs
Target Audience:Key target audiences include on-farm nutritionists and nutrition technical consultants, feed and nutrition supplement companies, dairy farmers, regional and national extension agents, veternairians, and other academics. Changes/Problems:We requested a 1 year no-cost extension due to a delay in starting the animal work for our in vivo study. This was due to availability of transiton cows at our dairy research farm in 2023 and early 2024. What opportunities for training and professional development has the project provided?This project provided training to two Ph.D. students, two postdoctoral fellows, and three undergraduate students participating in independent research. Additionally, four undergraduate students gained research experience. All graduate students presented their research at national conferences. Two undergraduate students presented their research at university and regional conferences. Upon graduation, graduate students have enteredthe dairy industry, pursuing dairy-related academic positions, or continuing their graduate education. How have the results been disseminated to communities of interest?Results have been submitted to peer-reviewed journals and presented at national/international dairy science conferences (abstracts), presentations and articles at industry focused dairy nutrition conference, and presentations at regional dairy extension meetings with dairy industry groups. Publications have also been highlighted in a new lab LinkedIn page run by the PI and graduate students (https://bit.ly/LockLipidLab). Beyond the academic community, these projects results, and impacts are mostly with (and multiplied through) nutrition consultants, dairy nutrition companies, and veterinarians who advise dairy farmers. Many of these professionals are M.S. or Ph.D. trained nutritionists or DVM's. Often referred to as a 'train the trainer' approach, this is a vital conduit for delivering research and extension to the entire dairy industry, including dairy producers. Most dairy farmers rely heavily on their nutrition consultants, feed suppliers, and veterinarians to make important recommendations and decisions. This is a critical dynamic because more than 50% of a dairy farm's total variable costs are associated with dairy cow feeds and dietary supplements. Likewise, these consultants rely on research findings and advice of dairy faculty to advise dairy producers. Through the variety of disseminations models described above, nutritionists have the available information at hand allowing them to implement nutritional changes on farm. What do you plan to do during the next reporting period to accomplish the goals?In the upcoming year, we will continue our in vivo study to elucidate the effects of oleic acid supplementation throughout the transition period on milk production, body weight loss, adipose tissue insulin sensitivity, and lipogenic potential. Our final in vitro studies will conclude, demonstrating how oleic acid augments lipogenic responses and insulin sensitivity in bovine adipocytes. Additionally, we will continue our research investigating the feasibility of high-oleic soybeans as a cost-effective, locally sourced method for delivering oleic acid to dairy cows. This mechanism serves as the source of oleic acid for our capstone in vivo study. Results will be presented to academic and industry audiences and submitted for publication in peer-reviewed journals.

Impacts
What was accomplished under these goals? During the fourth year of this project we continued to work on our in vitro studies determining how oleic acid enhances lipogenic responses and insulin sensitivity in bovine adipocytes. Overall, our results show that oleic acid limits lipolysis by improving insulin sensitivity and demonstrated that lipogenesis in adipose tissue may be enhanced through PLIN5 activation in a PPARα dependent manner and may improve mitochondrial integrity reflecting a state of lipogenesis. Previous work was published in the Journal of Dairy Science with this paper in 2024 garnering a prestigious American Dairy Science Association Graduate Student Paper Publication Award. Additional work on this aim is currently being reviewed for publication in the journal Animal: The international journal of animal biosciences. Our attention also shifted to our in vivo studies. The start of this study was postponed due to constraints in cow availability. The study commenced in October 2024 and is currently ongoing. Prior to this, we conducted research to evaluate the potential of high oleic acid soybeans as a means of delivering oleic acid to dairy cows. Based on these findings, we opted to adopt this approach for delivering oleic acid throughout the transition period. This latter work has garnered significant attention within the industry, and we remain committed to exploring the ways in which high oleic soybeans can support animal production and health.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Lock, A. L. and A. M. Bales. 2024. Feeding high oleic soybeans to dairy cattle. Proc. Tri-State Dairy Nutrition Conference. Available at: https://www.tristatedairy.org
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Lock, A. L. and J. Parales-Gir�n. 2024. Challenging dogma with new research: fatty acid supplementation strategies for early lactation cows. Four-State Dairy Nutrition & Management Conference. Available at: http://fourstatedairy.org
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Lock, A. L.. and A. M. Bales. 2024. Feeding high-oleic soybeans: new research to field applications. Perdue Animal Nutrition Evening Symposium, Penn State Dairy Nutrition Workshop, Hershey, PA, November 2024. Available at: https://extension.psu.edu/dairy-nutrition-workshop
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Lock, A. L.. and G. A. Contreras. 2024. Fatty acids as bioactive nutrients in lactating dairy cows. American Dairy Science Association Annual Meeting, Functional Nutrients Ruminant Nutrition Symposium, West Palm Beach, FL, June 2024.
• Type: Other Journal Articles Status: Under Review Year Published: 2024 Citation: Abou-Rjeileh, U., A. L. Lock, and G. A. Contreras. 2025. Oleic acid promotes lipid accumulation in bovine adipocytes: the role of PPAR? activity. Animal: The international journal of animal biosciences

Progress 01/01/23 to 12/31/23

Outputs
Target Audience:Key target audiences include on-farm nutritionists and nutrition technical consultants, feed and nutrition supplement companies, dairy farmers, regional and national extension agents, veternairians, and other academics. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project helped provide training for 2 PhD students, 2 postdocs, along with 3 undergraduate students participating in independent research and 4 additional undergraduate students gaining research experience. All graduate students presented their research at national meetings. Two undergraduate students presented their research at university andregional conferences. Upon graduation, graduate students either enter the dairy industry or dairy related academic positions or continue their graduate education. How have the results been disseminated to communities of interest?Results have been submitted to a peer-reviewed journal and presented at national/international dairy science conferences (abstracts), presentations and articles at industry focused dairy nutrition conference, and presentations at regional dairy extension meetings with dairy industry groups. Publications have also been highlighted in a dairy nutrition Facebook site run by the PI. Beyond the academic community, these projects results, and impacts are mostly with (and multiplied through) nutrition consultants, dairy nutrition companies, and veterinarians who advise dairy farmers. Many of these professionals are M.S. or Ph.D. trained nutritionists or DVM's. Often referred to as a 'train the trainer' approach, this is a vital conduit for delivering research and extension to the entire dairy industry, including dairy producers. Most dairy farmers rely heavily on their nutrition consultants, feed suppliers, and veterinarians to make important recommendations and decisions. This is a critical dynamic because more than 50% of a dairy farm's total variable costs are associated with dairy cow feeds and dietary supplements. Likewise, these consultants rely on research findings and advice of dairy faculty to advise dairy producers. Through the variety of disseminations models described above, nutritionists have the available information at hand allowing them to implement nutritional changes on farm. What do you plan to do during the next reporting period to accomplish the goals?In this next year we will continue our in vitro studies and start our in vivo study to determine the effects of periparturient supplementation of oleic acid on milk production, body weight loss, and adipose tissue insulin sensitivity and lipogenic potential. Ourin vitro studies will determinehow oleic acid enhances lipogenic responses and insulinsensitivity in bovine adipocytes. We will also continue our work examining the potential for high oleic soybeans as a cost effective, home grown, means for the delivery of oleic acid to dairy cows. It is through this mechansim that we anticiapte to supply oleic acid for our capstone in vivo study for this project.

Impacts
What was accomplished under these goals? During the third year of this project our focus continued to be on our in vitro studies determining how oleic acid enhances lipogenic responses and insulin sensitivity in bovine adipocytes. Overall, our results show that oleic acid limits lipolysis by improving insulin sensitivity and demonstrated that lipogenesis in adipose tissue may be enhanced through PLIN5 activation in a PPARα dependent manner and may improve mitochondrial integrity reflecting a state of lipogenesis. Some of this work was recently published in the Journal of Dairy Science. We also carried out preliminary studies with an oleic acid-enriched calcium-salt to determine its ability to consistently deliver oleic acid to dairy cows. We are also examined the potential for high oleic acid soybeans as an alternative method of delivering oleic acid to dairy cows.This will aid in our large in vivo study to be completed as part of our grant. This latter work has gained much attention in the industry and we continue to examine ways that high oleic soybeans can support animal production and health.

Publications

• Type: Journal Articles Status: Published Year Published: 2023 Citation: Abou-Rjeileh, U., Jos�M. dos S. Neto, M. Chirivi, N. OBoyle, D. Salcedo, C. Prom, J. Laguna, J. Parales-Giron, A.L. Lock, and G.A. Contreras. 2023. Oleic acid abomasal infusion limits lipolysis and improves insulin sensitivity in adipose tissue from periparturient dairy cows. J. Dairy Sci. 106:43064323. doi:10.3168/jds.2022-22402.
• Type: Journal Articles Status: Published Year Published: 2023 Citation: Neto, J.M. dos S., C.M. Prom, and A.L. Lock. 2023. Abomasal infusion of oleic acid and exogenous emulsifier alter fatty acid digestibility and production responses of lactating dairy cows. J. Dairy Sci. 106:75917601. doi:10.3168/jds.2022-23038.
• Type: Journal Articles Status: Awaiting Publication Year Published: 2023 Citation: Bales, A.M., J. de Souza, and A.L. Lock. 2023. Milk production responses of dairy cows to fatty acid supplements with different ratios of palmitic and oleic acids in low- and high-fat basal diets. JDS Commun.. doi:10.3168/jdsc.2023-0415.
• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: U. Abou-Rjeileh, A. L. Lock, G. A. Contreras. Oleic acid promotes lipid accumulation and improves mitochondrial function in bovine adipocytes. American Dairy Science Association Annual Meeting, Ottawa Canada, June 2023.
• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: A. M. Bales, A. L. Lock. Oleic acid promotes lipid accumulation and improves mitochondrial function in bovine adipocytes. American Dairy Science Association Annual Meeting, Ottawa Canada, June 2023.

Progress 01/01/22 to 12/31/22

Outputs
Target Audience:Key target audiences include on-farm nutritionists and nutrition technical consultants, feed and nutrition supplementcompanies, dairy farmers, regional and national extension agents, and other academics. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project helped provide training for 3 PhD students, 1 postdoc, along with 2 undergraduate students participating inindependent research and 4 additional undergraduate students gaining research experience. All graduate students presentedtheir research at national meetings. Two undergraduate students presented their research at university and regionalconferences. Upon graduation, graduate students either enter the dairy industry or dairy related academic positions orcontinue their graduate education. How have the results been disseminated to communities of interest?Results have been submitted toa peer-reviewed journal and presentedat national/international dairy scienceconferences (abstracts), presentations and articles at industry focused dairy nutrition conference, and presentations atregional dairy extension meetings with dairy industry groups. Publications have also been highlighted in a dairy nutritionFacebook site run by the PI. Beyond the academic community, these projects results, and impacts are mostly with (andmultiplied through) nutrition consultants, dairy nutrition companies, and veterinarians who advise dairy farmers. Many of theseprofessionals are M.S. or Ph.D. trained nutritionists or DVM's. Often referred to as a 'train the trainer' approach, this is a vitalconduit for delivering research and extension to the entire dairy industry, including dairy producers. Most dairy farmers relyheavily on their nutrition consultants, feed suppliers, and veterinarians to make important recommendations and decisions.This is a critical dynamic because more than 50% of a dairy farm's total variable costs are associated with dairy cow feedsand dietary supplements. Likewise, these consultants rely on research findings and advice of dairy faculty to advise dairyproducers. Through the variety of disseminations models described above, nutritionists have the available information at handallowing them to implement nutritional changes on farm. What do you plan to do during the next reporting period to accomplish the goals?In this next year we will continue our in vitro studies. We will asloinitiate our in vivo study to determine the effects of periparturient supplementation of oleic acidon milk production, body weight loss, and adipose tissue insulin sensitivity and lipogenic potential and continue our in vitrostudies determining how oleic acid enhances lipogenic responses and insulin sensitivity in bovine adipocytes. We will also continue our work examining the potential for high oleic soybeans as a cost effective, home grown, means for the delivery of oleic acid to dairy cows.

Impacts
What was accomplished under these goals? During the second year of this project our focus continued to beon our in vitro studies determining how oleic acid enhances lipogenicresponses and insulin sensitivity in bovine adipocytes. Overall, our results show that oleic acid limits lipolysis by improvinginsulin sensitivity and demonstrated that lipogenesis in adipose tissue may be enhanced through PLIN5 activation in a PPARαdependent mannerand may improve mitochondrial integrity reflecting a state of lipogenesis. We also carried out preliminary studies with anoleic acid-enriched calcium-salt to determine its ability to consistently deliver oleic acid to dairy cows. This will aid in our large in vivo study to be completed as part of our grant. We are also examining the potential for high oleic acid soybeans as an alternativemethodof delivering oleic acid to dairy cows.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Abou-Rjeileh U, Chirivi M, Parales-Giron J, Prom C. M, Laguna J, Lock A. L, and Contreras G.A Oleic acid improves insulin sensitivity in periparturient dairy cow adipose tissue through PLIN5 and PPAR?. Phi Zeta Research Day, Michigan State University.
• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: U. Abou-Rjeileh, D. Salcedo, J. Parales, C. Prom, M. Chirivi, N.J. O⿿Boyle, J. Laguna, A. L. Lock, G. A. Contreras. Oleic acid limits lipolysis and improves mitochondrial function in adipose tissue from periparturient dairy cows. American Dairy Science Association Annual Meeting, Kansas City, June 2022.
• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: J. M. dos Santos Neto, U. Abou-Rjeileh, J. Parales-Giron, C. M. Prom, G. A. Contreras, A. L. Lock. Abomasal infusion of oleic acid improves plasma hormones and metabolites in early lactation dairy cows. American Dairy Science Association Annual Meeting, Kansas City, June 2022.
• Type: Journal Articles Status: Under Review Year Published: 2022 Citation: U. Abou-Rjeileh, J. M. dos Santos Neto, D. Salcedo, J. Parales, C. Prom, M. Chirivi, N.J. O⿿Boyle, J. Laguna, A. L. Lock, G. A. Contreras. Oleic acid abomasal infusion limits lipolysis and improves insulin sensitivity in adipose tissue from periparturient dairy cows. Journal of Dairy Science (submitted).
• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: A. M. Burch, J. de Souza, A. L. Lock. Rumen vs. abomasal infusion of oleic acid as an approach to determine the potential for an oleic acid-enriched calcium-salt to affect digestibility and production of dairy cows.American Dairy Science Association Annual Meeting, Kansas City, June 2022.

Progress 01/01/21 to 12/31/21

Outputs
Target Audience:Key target audiences include on-farm nutritionists and nutrition technical consultants, feed and nutrition supplement companies, dairy farmers, regional and national extension agents, and other academics. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project helped provide training for 3PhD students, 1postdoc, along with 2 undergraduate studentsparticipating in independent research and 4 additional undergraduate students gaining research experience.All graduate students presented their research at national meetings. Two undergraduate students presented their research atuniversity and regional conferences. Upon graduation, graduate students either enter the dairy industry or dairy related academic positions or continue their graduate education. How have the results been disseminated to communities of interest?Results have been published in peer-reviewed journals, presentations at national/international dairy science conferences(abstracts), presentations and articles at industry focused dairy nutrition conference, and presentations at regional dairyextension meetings with dairy industry groups. Publications have also been highlighted in a dairy nutrition Facebook site runby the PI.Beyond the academic community, these projects results, and impacts are mostly with (and multiplied through) nutrition consultants, dairy nutrition companies, and veterinarians who advise dairy farmers. Many of these professionals are M.S. or Ph.D. trained nutritionists or DVM's. Often referred to as a 'train the trainer' approach, this is a vital conduit for delivering research and extension to the entire dairy industry, including dairy producers. Most dairy farmers rely heavily on their nutrition consultants, feed suppliers, and veterinarians to make important recommendations and decisions. This is a critical dynamic because more than 50% of a dairy farm's total variable costs are associated with dairy cow feeds and dietary supplements. Likewise, these consultants rely on research findings and advice of dairy faculty to advise dairy producers. Through the variety of disseminations models described above, nutritionists have the available information at hand allowing them to implement nutritional changes on farm. What do you plan to do during the next reporting period to accomplish the goals?In this next year we will initiate our in vivo studies todetermine the effects of periparturientsupplementation of oleic acid onmilk production, body weight loss, and adipose tissue insulin sensitivity and lipogenic potential and continue our in vitro studies determininghow oleic acid enhances lipogenic responses and insulin sensitivity in bovine adipocytes.

Impacts
What was accomplished under these goals? During the first year of this project our focus was on our in vitro studies determininghow oleic acid enhances lipogenic responses and insulin sensitivity in bovine adipocytes. Overall, our results show that oleic acidlimits lipolysis by improving insulin sensitivity and demonstrated that lipogenesis in adipose tissue may be enhanced through PLIN5 activation in a PPARα dependent manner, and mayimprovemitochondrial integrity reflecting a state of lipogenesis.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Lock, A. L. 2021. Fatty acid nutrition of dairy cows: opportunities, challenges, and the future. Proc. Penn State Dairy Cattle Nutrition Workshop. Available at: https://extension.psu.edu/penn-state-dairy-cattle-nutrition-workshop
• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Abou-Rjeileh, U., A. L. Lock, and G. A. Contreras. 2021. Palmitic and oleic acids modulate lipogenesis in dairy cow adipocytes. J. Dairy Sci. Vol. 104 (Suppl. 1): 105.
• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Abou-Rjeileh, U., M. Chirivi, J. Parales-Giron, J. M. dos Santos Neto, C. M. Prom, J. Laguna, A. L. Lock, and G. A. Contreras. Oleic acid improves insulin sensitivity in adipose tissue of periparturient dairy cows. Phi Zeta Research Day, Michigan State University.
• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Abou-Rjeileh, U., M. Chirivi, J. Parales-Giron, C. M. Prom, J. Laguna, A. L. Lock, and G. A. Contreras. 2021. Oleic acid improves insulin sensitivity in dairy cow adipose tissue through PPAR? and PLIN5. The Conference of Research Workers in Animal Diseases (CRWAD), Chicago, IL, 2021. Available at: https://crwad.org/presentations/
• Type: Journal Articles Status: Published Year Published: 2021 Citation: de Souza, J., C. M. Prom, and A. L. Lock. 2021. Altering the ratio of dietary palmitic and oleic acids affects production responses during the immediate postpartum and carryover periods in dairy cows. J Dairy Sci 104:28962909.
• Type: Journal Articles Status: Published Year Published: 2021 Citation: de Souza, J., C. M. Prom, and A. L. Lock. 2021. Altering the ratio of dietary palmitic and oleic acids affects nutrient digestibility, metabolism, and energy balance during the immediate postpartum in dairy cows. J Dairy Sci 104:29102923.
• Type: Journal Articles Status: Published Year Published: 2021 Citation: Burch, A. M., A. Pineda, and A. L. Lock. 2021. Effect of palmitic acid-enriched supplements containing stearic or oleic acid on nutrient digestibility and milk production of low and high producing dairy cows. J. Dairy Sci. 104:8673-8684.
• Type: Journal Articles Status: Published Year Published: 2021 Citation: Prom, C. M. and A. L. Lock. 2021. Replacing stearic acid with oleic acid in supplemental fat blends improves fatty acid digestibility of lactating dairy cows. J. Dairy Sci. 104:99569966.
• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Lock, A. L. 2021. Fatty acid supplementation opportunities for early lactation dairy cows. Proc. Penn State Dairy Cattle Nutrition Workshop. Available at: https://extension.psu.edu/penn-state-dairy-cattle-nutrition-workshop