Alexander N. Hristov, Ph.D., P.A.S.

Professional Experience

• 2019-Present: Distinguished Professor of Dairy Nutrition, Department of Animal Science, Penn State
• 2013-2019: Professor of Dairy Nutrition, Department of Animal Science, Penn State
• 2008-2013: Associate Professor of Dairy Nutrition, Department of Animal Science, Penn State
• 1999-2008: Associate Professor, Department of Animal and Veterinary Science, University of Idaho
• 1997-1999: Term Research Scientist II, Agriculture Canada, Lethbridge Research Centre, Canada
• 1995-1997: Visiting Scientist, Agriculture Canada, Lethbridge Research Centre, Canada
• 1990-1991, 1993: Visiting Scientist, US Dairy Forage Research Center, Madison, Wisconsin
• 1983-1997: Research Scientist, Institute of Animal Sciences, Kostinbrod, Bulgaria

SOCIETY AFFILIATIONS AND SERVICE:

• American Dairy Science Association, American Society of Animal Science, Federation of Animal Science Societies, American Registry of Professional Animal Scientists.
• Co-Chair, Network and Database on Feed and Nutrition in Relation to Greenhouse gas Emissions (FNN), an activity of the Livestock Research Group within the Global Research Alliance.
• Feed Composition Committee of the National Animal Nutrition Program (NANP).
• Regional Project NC-2040 Committee representative: Metabolic Relationships in Supply of Nutrients for Lactating Cows.
• Editorial Board member, Journal of Dairy Science; Associate Editor, Journal of Agricultural Sciences (Cambridge); Past Associate and Division Editor, Ruminant Nutrition, Journal of Animal Science. Past Associate Editor, Canadian Journal of Animal Science.

 TEACHING RESPONSIBILITIES:

                ANSC420 Animal Nutrition and Feed Technology

                ANSC506 Ruminology

                ANSC410 Advanced Dairy Management, dairy nutrition section

                ANSC/GEOG/METEO 332N Science and Policy of Global Greenhouse Gas Emissions and Management

Lead Instructor: Dairy Production and Management MOOC (Massive Open Online Course; https://www.coursera.org/learn/dairy-production)

Refereed publications, books, and book chapters: over 200 (over 70 in the last 5 yrs.); Invited talks: over 70.

 SCHOLARSHIP ACCOMPLISHMENTS:

Google Scholar stats (updated January 2022)

Selected Publications:

Books: 

• Hristov, A. N. (Editor). 2022. Advances in sustainable dairy cattle nutrition. Burleigh Dodds Science Publishing Ltd., Cambridge, UK, (in preparation).
• W. C. White, D. Allen, P. K. Amar, J. Bogner, L. Bruhwiller, D. Cooley, C. Frankenberg, F. George, L. Hanle, A. N. Hristov, E. Kebreab, A. Leytem, M. Mastalerz, S. Wofsy. 2018. Improving Characterization of Anthropogenic Methane Emissions in the United States. Washington, DC: The National Academies Press. doi: https://doi.org/10.17226/24987.
• Ledgard, S., A. Leip, A. Uwizeye, A. Fusi, A. N. Hristov, A. K. Patra, A. Barbara, C. Gourley, C. Masso, C. L. Piquet, C. M. Cordovil, D. Hongmin, F. Vertès, G. Becoña, G. Thoma, A. D. Henderson, J. Helin, K. Linderholm, M. F. Aller, M. Redding, M. Binder, N. M. D. Cosme, R. Conant, R. Sakrabani, M. Rufino, Z. Zhu, Y. Wang, C. Liu, S. Hörtenhuber, M. Meier, R. Koelsch, N. Nsalambi, J. Buysse, G., W. Dylan, and D. Turner. FAO. 2018. Nutrient flows and associated environmental impacts in livestock supply chains: Guidelines for assessment (Version 1). Livestock Environmental Assessment and Performance (LEAP) Partnership. Rome, FAO. 196 pp. Licence: CC BY-NC-SA 3.0 IGO; ISBN: 978-92-5-130901-8.
• Hristov, A. N., J. Oh, C. Lee1, R. Meinen, F. Montes, T. Ott, J. Firkins, A. Rotz, C. Dell, A. Adesogan, W. Yang, J. Tricarico, E. Kebreab, G. Waghorn, J. Dijkstra, and S. Oosting. 2013. Mitigation of greenhouse gas emissions in livestock production – A review of technical options for non-CO₂ emissions. Edited by Pierre J. Gerber, Benjamin Henderson and Harinder P.S. Makkar. FAO Animal Production and Health Paper No. 177, FAO, Rome, Italy.
• Pfeffer, E., and A. N. Hristov (Editors). 2005. Nitrogen and Phosphorus Nutrition of Cattle: Reducing the Environmental Impact of Cattle Operations. CABI Publishing, Wallingford, U.K. (ISBN 0 85199 013 4).

 Book Chapters:

• Hristov, A. N. 2022. The use of supplements to mitigate enteric methane emission in dairy cattle. Chapter 10 in Advances in sustainable dairy cattle nutrition (A. N. Hristov, Editor). Burleigh Dodds Science Publishing Ltd., Cambridge, UK, (in preparation).
• Hristov, A. N., J. M. F. Johnson, C. W. Rice, M. E. Brown, R. T. Conant, S. J. Del Grosso, N. P. Gurwick, C. A. Rotz, U. M. Sainju, R. H. Skinner, T. O. West, B. R. K. Runkle, H. Janzen, S. C. Reed, N. Cavallaro, and G. Shrestha, 2018: Chapter 5: Agriculture. In Second State of the Carbon Cycle Report (SOCCR2): A Sustained Assessment Report [Cavallaro, N., G. Shrestha, R. Birdsey, M. A. Mayes, R. G. Najjar, S. C. Reed, P. Romero-Lankao, and Z. Zhu (eds.)]. U.S. Global Change Research Program, Washington, DC, USA, pp. 229-263, https://doi.org/10.7930/SOCCR2.2018.Ch5
• A. Jonker, C. Antwi, A. A. Biswas, S. A. Gunter, A. N. Hristov, C. Martin, E. M. K. Minnée, G. Renand, and G. C. Waghorn. 2020. The “GreenFeed” automated methane measurement system to determine enteric methane emissions from ruminants. In Eds. Jonker A and Waghorn GC, Guideline on technologies for estimating CH4 emissions from individual ruminants based on multiple spot-samples: GreenFeed, “sniffers”, hand-held laser and portable accumulation chambers, (chapter pages range). New Zealand Agricultural Greenhouse Gas Research Centre, New Zealand.
• Hristov, A. N. 2017. Agricultural Methanogenesis. Oxford Encyclopedia of Agriculture and the Environment. http://environmentalscience.oxfordre.com/view/10.1093/acrefore/9780199389414.001.0001/acrefore-9780199389414-e-190?rskey=O5r0SJ&result=4.
• Oh, J. and A. N. Hristov. 2016. Effects of plant-derived bio-active compounds on rumen fermentation, nutrient utilization, immune response, and productivity of ruminant animals. In Medicinal and Aromatic Crops: Production, Phytochemistry, and Utilization, Chapter 11, pp 167–186, DOI: 10.1021/bk-2016-1218.ch011, ACS Symposium Series, Vol. 1218.
• Patton, R. A., A. N. Hristov, and H. Lapierre, 2014. Protein Feeding and Balancing for Amino Acid in Lactating Dairy Cattle. Pp 599-621 in: Veterinary Clinics of North America. Eds. R. J. Van Saun and R. A. Smith. Elsevier, Philadelphia, USA.
• Ndegwa, P. M., A. N. Hristov, and J. A. Ogejo.  2011. Ammonia Emission from Animal Manure: Mechanisms and Mitigation Techniques. Pages 107-151 In Z. He, ed. Environmental Chemistry of Animal Manure.  Nova Science Publishers, Hauppauge, NY. ISBN: 978-1-61209-222-5.
• Hristov, A. N., and Jouany, J.-P. 2005. Factors affecting the efficiency of nitrogen utilization in the rumen. In: Pfeffer, E., and A. N. Hristov (eds.) Nitrogen and Phosphorus Nutrition of Cattle: Reducing the Environmental Impact of Cattle Operations. CAB International, Wallingford, U.K., pp. 117-166.

Peer-reviewed journal articles:

Journal of Dairy Science: Editor’s Choice Article Collection, Best of the Journal of Dairy Science® 2021. Stefenoni, H. A., S. E. Räisänen, S. F. Welchez, D. E. Wasson, C. F. A. Lage, A. Melgar, M. E. Fetter, P. Smith, M. Hennessy, B. Vecchiarelli, J. Bender, D. Pitta, C. L. Cantrell, C. Yarish, and A. N. Hristov. 2021. Effects of the macroalga Asparagopsis taxiformis and oregano leaves on methane emission, rumen fermentation, and lactational performance of dairy cows. J. Dairy Sci. 104:4157-4173. https://doi.org/10.3168/jds.2020-19686

Journal of Dairy Science’s 100 most highly cited papers published in JDS since the beginning of 2018: Melgar, A.; Harper, M. T.; Oh, J.; Giallongo, F.; Young, M. E.; Ott, T. L.; Duval, S.; Hristov, A. N. Effects of 3‐nitrooxypropanol on rumen fermentation, lactational performance, and resumption of ovarian cyclicity in dairy cows 2020. J. Dairy Sci. 103:410–432; https://doi.org/10.3168/jds.2019‐17085.                 

Journal of Dairy Science’s 100 most highly cited papers published in JDS since the beginning of 2018: Hristov, A. N.; Kebreab, E.; Niu, M.; Oh, J.; Bannink, A.; Bayat, A. R.; Boland, T. M.; Brito, A. F.; Casper, D. P.; Crompton, L. A.; Dijkstra, J.; Eugene, M.; Garnsworthy, P. C.; Haque, N.; Hellwing, A. L. F.; Huhtanen, P.; Kreuzer, M.; Kuhla, B.; Lund, . Symposium review: Uncertainties in enteric methane inventories, measurement techniques, and prediction models 2018. J. Dairy Sci. 101:6655–6674; https://doi.org/10.3168/jds.2017-13536

Journal of Dairy Science’s 100 most highly cited papers published in JDS since the beginning of 2018: Hristov, A. N.; Bannink, A.; Crompton, L. A.; Huhtanen, P.; Kreuzer, M.; McGee, M.; Noziere, P.; Reynolds, C. K.; Bayat, A. R.; Yanez‐Ruiz, D. R.; Dijkstra, J.; Kebreab, E.; Schwarm, A.; Shingfield, K. J.; Yu, Z. Invited review: Nitrogen in ruminant nutrition: A review of measurement techniques 2019. J. Dairy Sci. 102:5811–5852; https://doi.org/10.3168/jds.2018‐15829

Journal of Dairy Science’s 100 most highly cited papers published in JDS since the beginning of 2016: Giallongo, F., M. Harper, J. Oh, J. Lopes, H. Lapierre, R. A. Patton, I. Shinzato, C. Parys, and A. N. Hristov. 2016. Effects of rumen-protected methionine, lysine and histidine on lactation performance of dairy cows. J. Dairy Sci. 99:4437-4452. https://doi:10.3168/jds.2015-10822

Journal of Dairy Science’s 100 most highly cited papers published in JDS since the beginning of 2014: Lee, C., F. Giallongo, A. N. Hristov, H. Lapierre, T. W. Cassidy, K. S. Heyler, G. A. Varga, and C. Parys. 2015. Effect of dietary protein level and rumen protected amino acid supplementation on amino acid utilization for milk protein in lactating dairy cows. J. Dairy Sci. 98:1885–1902. https://doi:10.3168/jds.2014-8496

Journal of Dairy Science’s 100 most highly cited papers published in JDS since the beginning of 2012. Lee, C., A. N. Hristov, T. W. Cassidy, K. S. Heyler, H. Lapierre, G. A. Varga, M. J. de Veth, R. A. Patton, and C. Parys. 2012. Rumen-protected lysine, methionine, and histidine increase milk protein yield in dairy cows fed metabolizable protein-deficient diet. J. Dairy Sci. 95:6042–6060. https://doi.org/10.3168/jds.2012-5581

Journal of Dairy Science’s 100 most highly cited papers published in JDS since the beginning of 2011: Hristov, A. N., C. Lee, T. Cassidy, M. Long, K. Heyler, B. Corl, and R. Forster. 2011. Effects of lauric and myristic acids on ruminal fermentation, production, and milk fatty acid composition in lactating dairy cows. J. Dairy Sci. 94:382–395. https://doi.org/10.3168/jds.2010-3508

In the last 5 years:

Silvestre, T., S. E. Räisänen, S. F. Cueva, D. E. Wasson, C. F. A. Lage,3, L. F. Martins, E. Wall, and A. N. Hristov. 2022. Effects of a combination of Capsicum oleoresin and clove essential oil on metabolic status, lactational performance, and enteric methane emissions in dairy cows. J. Dairy Sci. (accepted).

Dipti W Pitta, Nagaraju Indugu, Audino Melgar, A. N. Hristov, Krishna Challa, Bonnie Vecchiarelli, Meagan Hennessy, Kapil Narayan, Stephane Duval, Maik Kindermann, and Nicola Walker. 2022. The effect of 3-nitrooxypropanol, a potent methane inhibitor, on ruminal microbial gene expression profiles in dairy cows. Microbiome (accepted).

Martins, L. F., D. E. Wasson, and A. N. Hristov. 2022. Feeding dairy cows for improved metabolism and health. Animal Frontiers (accepted).

Congio, G. F. S., A. Bannink, O. L. Mayorga, J. P. P. Rodrigues, A. Bougouin, E. Kebreab, P. C. F. Carvalho, A. L. Abdalla, A. L. G. Monteiro, J. C. Ku-Vera, J. I. Gere, C. Gomez , and A. N. Hristov. 2022. Prediction of enteric methane production and yield in sheep using a Latin America and Caribbean database. Livest. Sci. 264: 105036 https://doi.org/10.1016/j.livsci.2022.105036

Tee, T. P., Y. M. Goh, M. H. M. Zainudin, S. C. L. Candyrine, K. Sommart, K. Kongphitee, W. Sumamal, I. Phaowphaisal, R. Namsilee, W. Angthong, S. Sunato, O. Keaokliang, K. Maeda, N. V. Thu, T. T. Trung, N. T. K. Dong, A. Purnomoadi, M. Kurihara, A. Jayanegara, K. Higuchi, Y. Kobayashi, F. Ohtani, H. Abe, F. Terada, H. Kumagai, H. Matsuyama, I. Nonaka, N. Takusari, N. Shiba, K. Hosoda, T. Suzuki, Y. Kamiya, T. Nishida, K. Hayasaka, M. Shibata, M. Wang, Z. L. Tan, R. Wang, E. Kebreab, H. J. van Lingen, A. N. Hristov, and J. B. Liang. 2022. Prediction of enteric methane production, yield and intensity in South-east Asia beef cattle using an intercountry database. Anim. Feed Sci. Technol. (accepted).

Martins, L. F., J. Oh, M. Harper, A. Melgar, S. E. Räisänen, X. Chen, K. Nedelkov, T. P. Karnezos, and A. N. Hristov. 2022. Effects of an exogenous enzyme preparation extracted from a mixed culture of Aspergillus spp. on lactational performance, metabolism, and digestibility in primiparous and multiparous cows. J. Dairy Sci. (accepted).

Hristov, A. N., A. Melgar, D. Wasson, and C. Arndt. 2022. Symposium invited review: Effective nutritional strategies to mitigate enteric methane in dairy cattle. J. Dairy Sci. (accepted).

Bougouin, A., A. N. Hristov, E. Kebreab, D. Zanetti, L. N. Rennó, A. C. B. Menezes, J. M. Silva, Valadares, S. C., Alhadas, L. D. S. M. Mariz, L. F. Prados, K. Beauchemin, W. Yang, K. Koening, K. Goossens. 2022. Prediction of nitrogen excretion from beef cattle fed a wide range of diets: a meta-analysis. J. Anim. Sci. (accepted).

Tricarico, J. M., Y. de Haas, A. N. Hristov, E. Kebreab, T. Kurt, F. Mitloehner, and D. Pitta. 2022. Symposium review: Development of a funding program to support research on enteric methane mitigation from ruminants. J. Dairy Sci. (accepted).

Congio, G.F.S., Bannink, A., Mayorga, O.L., Rodrigues, J.P.P., Bougouin, A., Kebreab, E., Silva, R.R., Maurício, R.M., da Silva, S.C., Oliveira, P.P.A., Muñoz, C., Pereira, L.G.R., Gómez, C., Ariza-Nieto, C., Ribeiro-Filho, H.M.N., Castelán-Ortega, O.A., Rosero-Noguera, J.R., Paz, M., Rodrigues, P.H.M., Marcondes, M.I., Astigarraga, L., Abarca, S., Hristov, A.N., 2022. Prediction of enteric methane production and yield in dairy cattle using a Latin America and Caribbean database. Science of the Total Environment (accepted).

Bougouin, A., A. N. Hristov, M.J. Aguerre, S. Ahvenjärvi, C. Arndt, A. Bannink, A.R. Bayat, C. Benchaar, T. Boland, W.E. Brown, L. A. Crompton, F. Dehareng, J. Dijkstra, I. Dufrasne, M. Eugene, E. Froidmont, S. van Gastelen, P. Garnsworthy, A. Halmemies-Beauchet-Filleau, S. Herremans, P. Huhtanen, M. Johansen, M. Kreuzer, B. Kuhla, F. Lessire, P. Lund, E.M.K. Minnee, C. Munoz, M. Niu, P. Noziere, D. Pacheco, E. Prestløkken, C. K. Reynolds, A. Sagaye, A. Schwarm, K. J. Shingfield, J.W. Spek, M. Terranova, A. Vanhatalo, M. Wattiaux, M.R. Weisbjerg, D. R. Yáñez-Ruiz, Z. Yu, and E. Kebreab. 2022. Prediction of nitrogen excretion from data on dairy cows fed a wide range of diets compiled in an intercontinental database: A meta-analysis. J. Dairy Sci. 105. https://doi.org/10.3168/jds.2021-20885

Wang, R. J. Chang, Q. Li, A. N. Hristov, P. Smith, Z. Bai, Z. Tan, and M. Wang. 2022. China’s low emission pathways towards climate neutral for animal-derived foods. Innovation 3(2): 100220. https://doi.org/10.1016/j.xinn.2022.100220  

Arndt, C., A. N. Hristov, W. J. Price, S. C. McClelland, A. M. Pelaez, S. F. Cueva, J. Oh, A. Bannink, A. R. Bayat, L. A. Crompton, J. Dijkstra, M. A. Eugène, D. Enahoro, E. Kebreab, M. Kreuzer, M. McGee, C. Martin, C. J. Newbold, C. K. Reynolds, A. Schwarm, K. J. Shingfield, J. B. Veneman, D. R. Yáñez-Ruiz, and Z. Yu. 2022. Full Adoption of Strategies to Mitigate Enteric Methane Emissions by Ruminants and How They Can Help to Meet the 1.5°C Climate Target by 2030 but Not 2050. Proc. Nat. Acad. Sci. U.S.A. 119 (20) e2111294119; https://doi.org/10.1073/pnas.2111294119

Silvestre, T., M. Fetter, S. E. Räisänen, C. F. A. Lage, H. Stefenoni, A. Melgar, S. F. Cueva, D. E. Wasson, L. F. Martins, T. P. Karnezos, and A. N. Hristov. 2022. Performance of dairy cows fed normal- or reduced-starch diet supplemented with an exogenous enzyme preparation. J. Dairy Sci. 105:2288–2300. https://doi.org/10.3168/jds.2021-21264

Indugu, N., V. S. Shabtai, C. F. A. Lage, S. E. Räisänen, A. Melgar, K. Nedelkov, X. Chen, J. Oh, B. Vecchiarelli, M. Hennessy, J. S. Bender, A. N. Hristov, D. W. Pitta. 2021. Comparing noninvasive sampling techniques with standard cannula sampling method for ruminal microbial analysis. J. Dairy Sci. Comm. 2: 329-333. https://doi.org/10.3168/jdsc 2021 -0094  

Dillon, J.A., K.R. Stackhouse-Lawson, G.J. Thoma, S.A. Gunter, C.A. Rotz, E. Kebreab, D.G. Riley, L.O. Tedeschi, J. Villalba, F. Mitloehner, A. N. Hristov, S.L. Archibeque, John P. Ritten, and Nathaniel D. Mueller. 2021. Current state of enteric methane and the carbon footprint of beef and dairy cattle in the United States. Animal Frontiers 11:57–68. https://doi.org/10.1093/af/vfab043

Fetter, M. E., D. M. Cunningham, F. Gambonini, S. E. Räisänen, T. L Ott, and A. N. Hristov. 2021. Short communication: Postpartum plasma amino acid concentration in primi- and multiparous Holstein cows. Anim. Feed Sci. Technol. 281:115101. https://doi.org/10.1016/j.anifeedsci.2021.115101

Räisänen, S. E., X. Zhu, C. Zhou, C. F. A Lage, M. Fetter, T. Silvestre, H. Stefenoni, D. E. Wasson, S. F. Cueva, J.-S. Eun, J. O. Moon, J. S. Park, and A. N. Hristov. 2021. Production effects and bioavailability of n-acetyl-l-methionine in lactating dairy cows. J. Dairy Sci. 105:313–328. https://doi.org/10.3168/jds.2021-20540

Räisänen, S. E., C. F. A. Lage, C. Zhou, A. Melgar, T. Silvestre, D. E. Wasson, S. F. Cueva, J. Werner, T. Takagi, M. Miura, and A. N. Hristov. 2021. Lactational performance, and plasma and muscle amino acid concentrations in dairy cows fed diets supplying two levels of digestible histidine and metabolizable protein. J. Dairy Sci. 105:170–187. https://doi.org/10.3168/jds.2021-20800

Oh. J., M. T. Harper, A. Melgar, S. Räisänen, X. Chen, K. Nedelkov, M. Fetter, T. Ott, E. H. Wall, and A. N. Hristov. 2021. Dietary supplementation with rumen-protected capsicum during the transition period improves metabolic status of dairy cows. J. Dairy Sci. 104:11609-11620. https://doi.org/10.3168/jds.2020-19892

Congio, G. F. S., A. Bannink, O. L. M. Mogollón, Latin America Methane Project Collaborators, and A. N. Hristov. 2021. Enteric methane mitigation strategies for ruminant livestock systems in the Latin America and Caribbean region: A Meta-Analysis. J. Cleaner Prod. 312:127693. https://doi.org/10.1016/j.jclepro.2021.127693

Kaplan-Shabtai V. K., N. Indugu, M. L. Hennessy, B. Vecchiarelli, J. Bender, D. Stefanovski, C. F. A. Lage, S. E. Räisänen, A. Melgar, K. Nedelkov, M. E. Fetter, A. Feranandez, A. Spitzer, A. N. Hristov, and D. W. Pitta. 2021. Using statistical equation modelling to understand interactions between bacterial and archaeal populations and volatile fatty acid proportions in the rumen. Frontiers in Microbiol. 12: 611951. https://doi.org/10.3389/fmicb.2021.611951

Cueva, S. F., H. Stefenoni, A. Melgar, S. E. Räisänen, C. F. A. Lage, D. Wasson, M. E. Fetter, and A. N. Hristov. 2021. Lactational performance, rumen fermentation and enteric methane emission of dairy cows fed amylase-enabled corn silage. J. Dairy Sci. 104:9827-9841. https://doi.org/10.3168/jds.2021-20251

Ocko, I. B., D. Shindell, M. Oppenheimer, A. N. Hristov, S. W. Pacala, D. L. Mauzerall, Y. Xu, S. P. Hamburg. 2021. Acting rapidly to deploy readily available methane mitigation measures by sector can immediately slow global warming. Environmental Research Letters 16 054042. https://doi.org/10.1088/1748-9326/abf9c8  

Pitta DW, Melgar A, Indugu N, Pappalardo C, Hennessy M, Vecchiarelli B, Kaplan-Shabtai V, Kindermann M, Walker, N, A. N. Hristov. 2021. Temporal changes in total and metabolically active ruminal methanogens induced by 3-nitrooxypropanol in dairy cows. J. Dairy Sci. 104:8721-8735. https://doi.org/10.3168/jds.2020-19862.

Räisänen, S. E., C. F. A. Lage, J. Oh, A. Melgar, K. Nedelkov, X. Chen, M. Miura, C. Parys, and A. N. Hristov. 2021. Histidine dose-response effects on lactational performance and plasma amino acid concentrations in lactating dairy cows: 1. Metabolizable protein-adequate diet. J. Dairy Sci. 104:9902-9916. https://doi.org/10.3168/jds.2021-20188

Räisänen, S. E., C. F. A. Lage, M. E. Fetter, A. Melgar, A. M. Pelaez, H. A. Stefenoni, D. E. Wasson, S. F. Welchez, X. Zhu, M. Miura, A. N. Hristov. 2021. Histidine dose-response effects on lactational performance and plasma amino acid concentrations in lactating dairy cows: 2. metabolizable protein-deficient diet. J. Dairy Sci. 104:9917-9930. https://doi.org/10.3168/jds.2021-20189

Arndt, C., A. N. Hristov, W. J. Price, S. C. McClelland, A. M. Pelaez, S. F. Cueva, J. Oh, A. Bannink, A. R. Bayat, L. A. Crompton, J. Dijkstra, M. A. Eugène, E. Kebreab, M. Kreuzer, M. McGee, C. Martin, C. J. Newbold, C. K. Reynolds, A. Schwarm, K. J. Shingfield, J. B. Veneman, D. R. Yáñez-Ruiz, and Z. Yu. 2021. Strategies to Mitigate Enteric Methane Emissions by Ruminants – A Way to Approach the 2.0°C Target. Preprint. https://agrirxiv.org/search-details/?pan=20210085288. https://doi.org/10.31220/agriRxiv.2021.00040

Church, C. D., S. K. Fishel, M. R. Reiner, P. J. A. Kleinman, A. N. Hristov, and R. B. Bryant. 2020. Pilot scale investigation of phosphorus removal from swine manure by the MAnure PHosphorus Extraction (MAPHEX) System. Applied Engineering in Agriculture 36: 525–531. https://doi:10.13031/aea13698  

Lage, C. F. A., S. E. Räisänen, A. Melgar, K. Nedelkov, X. Chen, J. Oh, M.E. Young, J. Bender, B. Vecchiarelli, N, Indugu, D. Pitta, and A. N. Hristov. 2020. Comparison of two sampling techniques for evaluating ruminal fermentation and microbiota in the ruminal planktonic phase of dairy cows. Frontiers Microbiology. 11: 618032. https://doi.org/10.3389/fmicb.2020.618032

Stefenoni, H. A., S. E. Räisänen, S. F. Welchez, D. E. Wasson, C. F. A. Lage, A. Melgar, M. E. Fetter, P. Smith, M. Hennessy, B. Vecchiarelli, J. Bender, D. Pitta, C. L. Cantrell, C. Yarish, and A. N. Hristov. 2021. Effects of the macroalga Asparagopsis taxiformis and oregano leaves on methane emission, rumen fermentation, and lactational performance of dairy cows. J. Dairy Sci. 104:4157-4173. https://doi.org/10.3168/jds.2020-19686

Westphalen, M. F., P. H. V. Carvalho, J. Oh, A. N. Hristov, W. B. Staniar. and T. L. Felix. 2020. Effects of feeding rumen-protected Capsicum oleoresin on growth performance, health status, and total tract digestibility of growing beef cattle. Anim. Feed Sci. Technol. https://doi.org/10.1016/j.anifeedsci.2020.114778  

Lage, C. F. A., S. E. Räisänen, H. Stefenoni, A. Melgar, X. Chen, J. Oh, D. M. Kniffen, R. A. Fabin and A. N. Hristov. 2020. Lactational performance, enteric gas emissions, and plasma amino acid profile of dairy cows fed diets with soybean or canola meals included on an equal protein basis. J. Dairy Sci. 104: 3052-3066. https://doi.org/10.3168/jds.2020-18851

Vijn, S., D. P. Compart, N. Dutta, A. Foukis, M. Hess, A. N. Hristov, K. Kalscheur, E. Kebreab, S. V. Nuzhdin, N. N. Price, Y. Sun, J. M. Tricarico, A. Turzillo, M. R. Weisbjerg, C. Yarish, and T. Kurt. 2020. Key Considerations for the Use of Seaweed to Reduce Enteric Methane Emissions from Cattle. Frontiers in Veterinary Science, Dec. 2020, https://doi.org/10.3389/fvets.2020.597430   

Melgar, A., C. F. A. Lage, K. Nedelkov, S. E. Räisänen, H. Stefenoni, M. E. Fetter, X. Chen, J. Oh, S. Duval, M. Kindermann, N. D. Walker, and A. N. Hristov. 2020. Enteric methane emission, milk production and composition of dairy cows fed 3-nitrooxypropanol. J. Dairy. Sci 104:357-366. https://doi.org/10.3168/jds.2020-18908  

Melgar, A., K. Nedelkov, C. M. M. R. Martins, K. C. Welter, X. Chen, S. E. Räisänen, M. T. Harper, J. Oh, S. Duval, and A. N. Hristov. 2020. Short communication: Short-term effect of 3-nitrooxypropanol on feed dry matter intake in lactating dairy cows. J. Dairy Sci. 103:11496–11502. https://doi.org/10.3168/jds.2020-18331

Hristov, A. N., and A. Melgar. 2020. Short communication: Relationship of dry matter intake with enteric methane emission measured with the GreenFeed system in dairy cows receiving a diet without or with 3-nitrooxypropanol. Animal 14(S3):s484–s490. https://doi:10.1017/S1751731120001731

Räisänen, S. E., C. M. M. R. Martins, K. Nedelkov, J. Oh, M. T. Harper, A. Melgar, X. Chen, C. Parys, R. A. Patton, M. Miura, and A. N. Hristov. 2020. Bioavailability of rumen-protected methionine, lysine and histidine assessed by fecal free amino acid excretion. Anim. Feed Sci. Technol. 268 October 2020, 114595 https://doi.org/10.1016/j.anifeedsci.2020.114595.

Nedelkov, K., X. J. Chen, C.M.M.R. Martins, A. Melgar, M.T. Harper, S. Räisänen, J. Oh, T. L. Felix, E. Wall, and A. N. Hristov. 2020. Short communication: Alternative selenium supplement for sheep. Anim. Feed Sci. Technol. 261: March 2020, 114390. https://doi.org/10.1016/j.anifeedsci.2020.114390.

Melgar, A., K. C. Welter, K. Nedelkov, C. M. M. R. Martins, M. T. Harper, J. Oh, S. E. Räisänen, X. Chen, S. F. Cueva, S. Duval, and A. N. Hristov. 2020. Dose-response effect of 3-nitrooxypropanol on enteric methane emission in dairy cows. J. Dairy Sci. 103:6145–6156. https://doi.org/10.3168/jds.2019-17840

Melgar, A., M. T. Harper, J. Oh, F. Giallongo, M. E. Young, T. L. Ott, S. Duval, and A. N. Hristov. 2020. Effects of 3-nitrooxypropanol on rumen fermentation, lactational performance, and the resumption of ovarian cyclicity in dairy cows. J. Dairy Sci. 103:410–432. https://doi.org/10.3168/jds.2019-17085

Hristov, A. N., M. T. Harper, G. Roth, C. Canale, and P. Huhtanen. 2020. Effect of ensiling time on corn silage neutral-detergent fiber degradability and relationship between laboratory fiber analyses and in vivo digestibility. J. Dairy Sci. 103:2333–2346. DOI: https://doi.org/10.3168/jds.2019-16917.

Chen, X., K. Nedelkov, J. Oh, M. T. Harper, E. H. Wall, and A. N. Hristov. 2019. Effect of a blend of an artificial sweetener and capsicum on productive performance and blood chemistry in lambs. Anim. Feed Sci. Technol. https://doi.org/10.1016/j.anifeedsci.2019.114308.

Harper, M. T., J. Oh, A. Melgar, K. Nedelkov, S. Räisänen, X. Chen, C. M. M. R. Martins, M. Young, T. L. Ott, D. M. Kniffen, R. A. Fabin, and A. N. Hristov. 2019. Production effects of feeding extruded soybean meal to early-lactation dairy cows. J. Dairy Sci. 102:8999-9016. https://doi:10.3168/jds.2019-16551

Nedelkov, K. V., A. N. Hristov, and N. A. Todorov. 2019. Variability in rumen degradability and intestinal digestibility of sunflower meals protein. Bulg. J. Agric. Sci. 25:370–374.

Leip, A., S. Ledgart, Am Uwizeye, J. Palhares, F. Aller, B. Amon, M. Binder, C. M. D. S. Cordovil, H. Dong, A. Fusi, S. Hörtenhuber, A. N. Hristov, R. Koelsch, C. Liu, C. Masso, N. V. Nkongolo, A. K. Patra, M. R. Redding, M. C. Rufino. 2019. The value of manure - manure as co-product in life cycle assessment. J. Environ. Manage. 241:293-304.

van Lingen, H. J., M. Niu, E. Kebreab, S. C. Valadares Filho, J. A. Rooke, A. Schwarm, M. Kreuzer, P. I. Hynd, M. Caetano, M. Eugène, C. Martin, M. McGee, P. O'Kiely, M. Hünerberg, T. A. McAllister, T. T. Berchielli, J. D. Messana, N. Peiren, A. V. Chaves, E. Charmley, N. A. Cole, K. E. Hales, S.-S. Lee, A. Berndt, C. K. Reynolds, L. A. Crompton, A.-R. Bayat, D. R. Yáñez-Ruiz, Z. Yu, A. Bannink, J. Dijkstra, D. P. Casper, and A. N. Hristov. 2019 Prediction of enteric methane production, yield and intensity of beef cattle using an intercontinental database. Agriculture, Ecosystems & Environment 283:106575. https://doi.org/10.1016/j.agee.2019.106575

Benaouda, M., X. Li, C. Martin, E. Kebreab, A. N. Hristov, Z. Yu, D. R. Yáñez-Ruiz, C. K. Reynolds, L. A. Crompton, J. Dijkstra, A. Bannink, A. Schwarm, M. Kreuzer, M. McGee, P. Lund, A. L. F. Hellwing, M. R. Weisbjerg, P. J. Moate, A. R. Bayat, K. J. Shingfield, N. Peiren, and M. Eugène. 2019. Evaluation of the performance of existing mathematical models predicting enteric methane emissions from ruminants: animal categories and dietary mitigation strategies. Anim. Feed Sci. Technol. 255:114207. https://doi.org/10.1016/j.anifeedsci.2019.114207

Oh, J., M. Harper, A. Melgar, D. M. Paulus Compart, and A. N. Hristov. 2019. Effect of Saccharomyces cerevisiae-based direct-fed microbial and exogenous enzyme products on enteric methane emission and productivity of lactating dairy cows. J. Dairy Sci. 102:6065–6075.

Hristov, A. N., A. Bannink, L. A. Crompton, P. Huhtanen, M. Kreuzer, M. McGee, P. Nozière, C. K. Reynolds, A. R. Bayat, D. R. Yáñez-Ruiz, J. Dijkstra, E. Kebreab, A. Schwarm, K. J. Shingfield, and Z. Yu. 2019. Nitrogen in ruminant nutrition: a review of measurement techniques. J. Dairy Sci. 102:5811–5852.

Oh, J., M. T. Harper, and A. N. Hristov. 2019. Effects of lowering crude protein supply alone or in a combination with an essential oil product on productivity, rumen function and nutrients utilization in lactating dairy cows. Animal 17:1-9. doi: 10.1017/S1751731119001083.

Huhtanen, P., M. Ramin, and A. N. Hristov. 2019. Enteric methane emission can be reliably measured by the GreenFeed monitoring unit. Livest. Sci. 222:31-40.

Nedelkov, K., M. T. Harper, A. Melgar, X. Chen, S. Räisänen, C. M. M. R. Martins, J. Faugeron, E. H. Wall, and A. N. Hristov. 2019. Preference of flavored concentrate premixes by young ruminants. J. Dairy Sci. 102:388–394.

Cheema, M., A. Patterson, A. Hristov, and F. M. Harte. 2018. The association of lipophilic phospholipids with native bovine casein micelles: effect of lactation stage and casein micelle size. J. Dairy Sci. 101: 8672-8687.

Huhtanen, P., and A. N. Hristov. 2018. Letter to the Editor: Challenging the “sniffer” method for screening dairy cows to breeding reduced methane emissions. J. Dairy Sci. 101:9619–9620.

Church, C. D., A. N. Hristov, R. B. Bryant, P. J. A. Kleinman, S. K. Fishel, and M. Reiner. 2018. Versatility of the Manure Phosphorus Extraction (MAPHEX) System in Removing Phosphorus, Odor, Microbes, and Alkalinity from Dairy Manures: A Four-Farm Case Study. Appl. Eng. Agric. 34:567-572.

Hristov, A. N., E. Kebreab, M. Niu, J. Oh, C. Arndt, A. Bannink, A. R. Bayat, A. F. Brito, D. Casper, L. A. Crompton, J. Dijkstra, P. C. Garnsworthy, N. Haque, A. L. F. Hellwing, P. Huhtanen, M. Kreuzer, B. Kuhla, P. Lund, J. Madsen, S. C. McClelland, P. Moate, C. Muñoz, N. Peiren, J. M. Powell, C. K. Reynolds, A. Schwarm, K. J. Shingfield, T. M. Storlien, M. R. Weisbjerg, Z. Yu, T.B. Boland, C. Martin, M. Eugène, D. R. Yáñez-Ruiz, S. Muetzel. 2018. Symposium review: Uncertainties in enteric methane inventories, measurement techniques, and prediction models. J. Dairy Sci. 101:6655-6674. https://doi.org/10.3168/jds.2017-13536

Oh, J., M. Harper, C. H. Lang, E. H. Wall, and A. N. Hristov. 2018. Effects of phytonutrients alone or in combination with monensin on productivity in lactating dairy cows. J. Dairy Sci. 100:5974–5983.

Niu, M., E. Kebreab, A. N. Hristov, J. Oh, C. Arndt, A. Bannink, A. R. Bayat, A. F. Brito, T. Boland, D. Casper, L. A. Crompton, J. Dijkstra, M. A. Eugène, P. C. Garnsworthy, M. N. Haque, A. L. F. Hellwing, P. Huhtanen, M. Kreuzer, B. Kuhla, P. Lund, J. Madsen, C. Martin, S. C. McClelland, M. McGee, P. J. Moate, S. Muetzel, C. Muñoz, P. O’Kiely, N. Peiren, C. K. Reynolds, A. Schwarm, K. J. Shingfield, T. M. Storlien, M. R. Weisbjerg, D. R. Yáñez-Ruiz, and Z. Yu. 2018. Prediction of enteric methane production, yield and intensity in dairy cattle using an intercontinental database. Global Change Biology 24:3368-3389. https://doi:10.1111/gcb.14094 One of the top 25 GCB most downloaded articles in 2018.

Potter, T., C. Arndt, and A. N. Hristov. 2018. Short communication: Increased somatic cell count is associated with milk loss and reduced feed efficiency in lactating dairy cows. J. Dairy Sci. 101: 9510-9515.

Harper, M. T., A. Melgar, J. Oh, K. Nedelkov, G. Sanchez, G. W. Roth, and A. N. Hristov. 2018. Inclusion of brown midrib dwarf pearl millet silage in the diet of lactating dairy cows. J. Dairy Sci. 101:5006-5019. https://doi:10.3168/jds.2017-14036   

Arndt, C., A. B. Leytem, D. Zavala-Araiza, A. N. Hristov, J.P. Cativiela, R. A. Alvarez, S. Conley,| C. Daube, I. Faloona, and S. C. Herndon. 2018. Short-term methane emissions from 2 dairy farms in California estimated by different measurement techniques and US Environmental Protection Agency inventory methodology: A case study. J. Dairy Sci. 101:11461–11479. doi: 10.3168/jds.2017-13881.

Hristov, A. N., M. Harper, R. Meinen, R. Day, J. Lopes, T. Ott, A. Venkatesh, and C. A. Randles. 2017. Discrepancies and uncertainties in bottom-up gridded inventories of livestock methane emissions for the contiguous United States. Environ. Sci. Technol. 51:13668–13677. https://doi.org/10.1021/acs.est.7b03332   

Hristov, A. N., M. Harper, J. Oh, F. Giallongo, J. C. Lopes, G. Cudoc, J. Clay, R. Ward, and L. E. Chase. 2017. Short communication: Variability in milk urea nitrogen and dairy total mixed ration composition in the Northeast United States. J. Dairy Sci. 101:1579–1584. https://doi.org/10.3168/jds.2017-12925

Hristov, A. N., A. T. Degaetano, C. A. Rotz, E. Hoberg, H. Skinner, T. Felix, H. Li, P. Patterson, G. Roth, M. Hall, T. L. Ott, L. Baumgard, W. Staniar, M. Hulet, C. Dell, A. Brito, D. Hollinger. 2017. Climate change effects on livestock in the northeast US and strategies for adaptation. Climatic Change, 146:33–45; https://doi:10.1007/s10584-017-2023-z

2017. Cheema, A. N. Hristov, F. M. Harte. 2017. Binding of low molecular weight hydrophobic active pharmaceutical ingredients to native casein micelles. J. Dairy Sci. 100:8670-8679.

Harper, M., J. Oh, F. Giallongo, J. C. Lopes, G. W. Roth, and A. N. Hristov. 2017. Using brown midrib dwarf forage sorghum silage and fall grown oat silage in lactating dairy cow rations. J. Dairy Sci. 100:5250–5265.

Harper, M., J. Oh, F. Giallongo, G. W. Roth, and A. N. Hristov. 2017. Effects of feeding triticale and wheat silages on feed intake, milk production and composition, and enteric methane production in lactating dairy cows. J. Dairy Sci. 100:6151–6163.

Oh, J., E. H. Wall, D. M. Bravo, and A. N. Hristov. 2017. INVITED REVIEW: Host-mediated effects of phytonutrients in ruminants. J. Dairy Sci. 100:5974–5983.

Oh, J., M. Harper, F. Giallongo, D. Bravo, E. H. Wall, and A. N. Hristov. 2017. Effects of rumen-protected Capsicum oleoresin on productivity and responses to a glucose tolerance test in lactating dairy cows. J. Dairy Sci. 100:1888–1901.

Oh, J., M. Harper, F. Giallongo, D. Bravo, E. H. Wall, and A. N. Hristov. 2017. Effects of rumen-protected Capsicum oleoresin on immune responses in dairy cows intravenously challenged with lipopolysaccharide. J. Dairy Sci. 100:1902–1913.

Lopes, J. C., M. T. Harper, F. Giallongo, J. Oh, L. Smith, A. M. Ortega-Perez, S. A. Harper, A. Melgar, D. M. Kniffen, R. A. Fabin, and A. N. Hristov. 2017. Effect of high-oleic acid soybeans on production performance, milk fatty acid composition, and enteric methane emission in dairy cows. J. Dairy Sci. 100:1122–1135.

Giallongo, F., M. T. Harper, J. Oh, C. Parys, I. Shinzato, and A. N. Hristov. 2017. Effects of a histidine-deficient diet on lactational performance of dairy cows. J. Dairy Sci. 100:2784–2800.

Weeks, H. L., and A. N. Hristov. 2017. Short communication: Discrepancies in milk urea nitrogen concentration analysis among milk processing laboratories in Pennsylvania. J. Dairy Sci. 100:1502–1506.