DAIRY SCIENCE DEPARTMENT

• Environmental issues associated with animal agriculture, including nutrient pollution of ground and surface water.
• Impact of nutrition and herd management on nutrient losses from dairy farms.
• Ruminant phosphorus digestion and metabolism.
• Wastewater treatment to achieve target nutrient composition of land-applied wastes.
• Endocrine disrupting chemicals in livestock wastes.
  
  Interested in graduate school in these areas?

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BS      1991     Cornell University: Animal Science
MS     1993     Michigan State University: Dairy Nutrition
Ph.D.  1997     University of Maryland & USDA-ARS Beltsville: Dairy Nutrition

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2005-pr.       Associate Professor.  Department of Dairy Science, Virginia Tech.
2000-05       Assistant Professor.  Department of Dairy Science, Virginia Tech.
1997-99       Research Scientist. Department of Dairy Science, Virginia Tech.
1993-97       Graduate Research Assistant. Department of Animal and Avian Sciences, University of Maryland.
1991-93       Graduate Research Assistant. Department of Animal Science, Michigan State University.
1990-91       Undergraduate Research Assistant. Department of Agricultural and Biological Engineering, Cornell University.
1984-1987   Farm Manager.  Mixed livestock and dairy farm, Portland, Connecticutt.

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2008           American Dairy Science Association (ADSA) Cargill Young Scientist Award
2008           Certificate of Teaching Excellence, Virginia Tech College of Agriculture and Life Sciences
2005           ADSA Foundation Scholar Lecture Award in Dairy Production
2001           Epsilon Sigma Phi National Honorary Extension Fraternity State Team Award
1997           ADSA Graduate Student Paper Competition winner.
1995-96      Purina Mills Graduate Research Fellowship.
1996           University of MD College of Agriculture/Richard F. Davis Memorial Scholarship.
1992-95      National Science Foundation Graduate Research Fellowship.
1994           American Feed Industry Association Graduate Scholarship.
1994           American Jersey Cattle Association/Bansen Scholarship.
1992           Purina Mills Graduate Research Fellowship (declined for NSF fellowship).

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• Phosphorus intake and excretion in lactating cows.
• Source and fate of endocrine disrupting chemicals in livestock wastes.
• Digestion and flow of phosphorus-containing compounds in feeds.

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• Increase understanding of the interaction of animal agriculture and the environment.
• Effect of nutrition on nutrient excretion by dairy cows, and potential impact on water quality.

• DASC 1574 - Introduction to Dairy Science.
  The scope of the dairy science undergraduate program is presented. Preparation for careers in dairy production and related industries. (1H, 1C).
• DASC 5084 - Advanced Ruminant Nutrition Colloquium.
  Meets weekly during fall and spring semester to review research papers. Course objectives are to improve students' awareness of classic and current work in the field, improve understanding of the strengths and weaknesses of various experimental designs and techniques, and improve students' ability to critique research. (1H, 1C).
• ALS 3134 - Livestock and the Environment. 
  This course addresses environmental issues associated with animal agriculture. Topics covered include nutrient contamination of water resources, odor emission from livestock farms, environmental regulations affecting animal agriculture, and management practices to reduce the environmental impact of farms. Students will visit area livestock farms implementing various nutrient management practices, and will develop nutrient management plans for case-study farms. This course is targeted to students intending careers in production agriculture, to provide them with understanding of management practices to reduce the impact of livestock farms on air and water quality. Pre-Requisites: Biology 1005/1006 or 1105/1106, Junior standing. (3H, 3C).
• Assistant Coach of the Virginia Tech Dairy Judging Team
• Advisor to the Virginia Tech Dairy Club

• Gungor, K., J. Arogo-Ogejo, K. F. Knowlton, and N. G. Love. 2009. Prefermentation performance of a continuous pilot-scale fermenter treating dairy manure for enhanced biological phosphorus removal. Bioresource Technol. 100: 2124-2129.
• Taylor, M. S., K. F. Knowlton, M. L. McGilliard, W. S. Swecker, J. D. Ferguson, Z. Wu and M. D. Hanigan. 2009. Dietary calcium has little effect on mineral balance and bone mineral metabolism through 20 weeks of lactation in Holstein cows. J. Dairy Sci. 92: 223-237.
• Mullarky, I. K., W. A. Wark, M. Dickenson, S. Martin, C. S. Petersson-Wolfe, and K. F. Knowlton. 2009. Analysis of immune function in lactating dairy cows on varying phosphorus diets. J. Dairy Sci. 92: 365-368.
• Zhao, Z., Y. Fang, N. G. Love, and K. F. Knowlton. 2009. Biochemical and biological assays of endocrine disrupting compounds in various manure matrices. Chemosphere 74: 551-555.
• Hollmann, M., K. F. Knowlton, M. R. Brosius, M. L. McGilliard, and G. L. Mullins. 2008. Phosphorus runoff potential of varying sources of manure applied to fescue pastures in Virginia. Soil Science 173: 721-735.
• Kozarek, J. L., M. L. Wolfe, N. G. Love, and K. F. Knowlton. 2008. Sorption of estrogen to three agricultural soils from Virginia, U.S.A. Trans. of the ASABE 51:1591-1597.
• Hill, S. R., K. F. Knowlton, K. M. Daniels, R. E. James, R. E. Pearson, A. V. Capuco,, and R. M. Akers. 2008. Effects of milk replacer composition on growth, nutrient excretion, and body composition in pre-weaned Holstein heifers, J. Dairy Sci. 91: 3145-3155.
• Daniels, K. M., S. R. Hill, K. F. Knowlton, R. E. James, M. L. McGilliard, and R. M. Akers. 2008. Effects of milk replacer composition on selected blood metabolites and hormones in pre-weaned Holstein heifers, J. Dairy Sci. 91:2628-2640.
• Hollmann, M., K. F. Knowlton, M. L. McGilliard, and G. L. Mullins. 2008. Nutrient runoff potential from fescue pastures using simulated rotational grazing of lactating dairy cows. Comm. Soil Sci. and Plant Anal. 39: 2648-2662.
• DeBusk, J. A., J. Arogo, K. F. Knowlton, and N. G. Love. 2008. Chemical phosphorus removal for separated flushed dairy manure. ASABE 244: 499-506.
• Bendfeldt, E., K. F. Knowlton, J. Arogo-Ogejo, and K. Holm. 2008. The Waste Solutions Forum: An innovative and cooperative approach to support the agricultural community and protect water quality. Comm. Dev. 38: 85-93.
• M. S. Taylor, K. F. Knowlton, M. L. McGilliard, and J. H. Herbein. 2008. Blood mineral, hormone, and osteocalcin responses of multiparous Jersey cows to an oral dose of 25-Hydroxyvitamin D3 prior to parturition. J. Dairy Sci. 91: 2408-2416.
• Hill, S. R., K. F. Knowlton, E. Kebreab, J. France and M. D. Hanigan. 2008. A model of phosphorus digestion and metabolism in the lactating dairy cow. J. Dairy Sci. 91: 2021-2032.
• Wilkes, C. O., K. J. Pence, A. M. Hurt, O. Becvar, K. F. Knowlton, M. L. McGilliard, and F. C. Gwazdauskas. 2008. Effect of relocation on locomotion and cleanliness in dairy cows. J. Dairy Res. 75: 19-23.
• Hollmann, M., K. F. Knowlton, and M. D. Hanigan. 2008. Evaluation of solids, nitrogen and phosphorus excretion models in lactating dairy cows. J. Dairy Sci. 91:1245-1257.
• Dou, Z., C. F. Ramberg Jr., L. Chapius-Lardy, J. D. Toth, Y. Wang, R. J. Munson, Z. Wu, L. E. Chase, R. A. Kohn, K. F. Knowlton, and J. D. Ferguson. 2007. A novel test for measuring and managing potential phosphorus loss from dairy cattle feces. Environ. Sci. Technol. 41: 4361-4366.
• Hill, S. R., K. F. Knowlton, R. E. James, R. E. Pearson, G. L. Bethard, and K. J. Pence. 2007. Nitrogen and phosphorus retention and excretion in late gestation dairy heifers. J. Dairy Sci.  90: 5634-42.
• Knowlton, K. F., M. S. Taylor, S. R. Hill, C. Cobb and K. F. Wilson. 2007. Manure nutrient excretion by lactating cows fed exogenous phytase and cellulose. J. Dairy Sci. 90: 4356-4360.
• Knowlton, K. F. and T. Denckla Cobb. 2006. Implementing waste solutions for dairy and livestock farms. J. Dairy Sci. 89: 1372-1383.
• Bosch, D. J., M. L. Wolfe, and K. F. Knowlton. 2006. Reducing phosphorus runoff from dairy farms. J. Env. Qual. 35: 918-927.
• Keene, B. E., K. F. Knowlton, J. H. Wilson, M. L. McGilliard, and C. Holtaway. 2005. Bone breaking strength in mature dairy cows. Transactions of the ASAE. 1637-1643.
• Knowlton, K. F., N. G. Love, and C. M. Parson. 2005. Dietary phosphorus effects on characteristics of mechanically separated dairy manure. Transactions of the ASAE. 48(3):1253-1258.
• Knowlton, K. F., C. M. Parsons, C. W. Cobb, and K. F. Wilson. 2005. Exogenous phytase plus cellulase and phosphorus excretion in lactating dairy cows. The Professional Animal Scientist. 21:212-216.
• Keene, B. E., K. F. Knowlton, M. L. McGilliard, L. A. Lawrence, S. M. Nickols-Richardson, J. H. Wilson, A. M. Rutledge, L. R. McDowell, and M. E. Van Amburgh. 2004. Measures of bone mineral content in mature dairy cows. J. Dairy Sci. 87: 3816-3825.
• K. M. Burkholder, A. D. Guyton, J. M. McKinney, and K. F. Knowlton. 2004. The effect of steam flaked or dry ground corn and supplemental phytic acid on nitrogen partitioning in lactating cows and ammonia emission from manure. J. Dairy Sci. 87: 2546-2553.
• Knowlton, K. F., J. S. Radcliffe, D. A. Emmerson, and C. L. Novak. 2004. Animal management to reduce phosphorus losses to the environment. J. Anim. Sci. 82 (E. Suppl.) E173-E195.
• Dou, Z., Ferguson, J. D., Fiorini, J., Toth, J. D., Alexander, S. M., Chase, L. E. , Ryan, C. M. , Knowlton, K. F., Kohn, R. A. , Peterson, A. B.,  Sims, J. T., and Z. Wu. 2003. Phosphorus feeding levels and critical control points on dairy farms. J. Dairy Sci 86: 3787-3795.
• Guyton, A.D., J. M. McKinney, and K. F. Knowlton. 2003. The effect of steam flaked or dry ground corn and supplemental phytic acid on phosphorus partitioning and ruminal phytase activity in lactating cows. J. Dairy Science 86:3972-3982.
• Knowlton, K. F., J. M. McKinney, and C. Cobb. 2002. Effect of a direct-fed fibrolytic enzyme formulation on nutrient intake, partitioning, and excretion in early and late lactation Holstein cows. J. Dairy Sci. 85:3328-3335.
• Knowlton, K. F. and J. H. Herbein. 2002. Phosphorus partitioning during early lactation in dairy cows fed diets varying in phosphorus content. J. Dairy Sci. J. Dairy Sci. 85:1227-1236.
• Zhengxia Dou, Katharine F. Knowlton, Richard A. Kohn, Zhiguo Wu, Larry D. Satter, Gangya Zhang, John D. Toth, and James D. Ferguson. 2002. Phosphorus characteristics of dairy feces affected by diets. J. Environ. Qual. 31:2058-2065.
• Knowlton, K. F. 2001. High grain diets for dairy cattle. Rec. Advances Anim. Nutr. Austr. 13:19-28.
• Knowlton, K. F., J. H. Herbein, M. A. Meister-Weisbarth, and W. A. Wark. 2001. Nitrogen and phosphorus partitioning in lactating Holstein cows fed different sources of dietary protein and phosphorus.  J. Dairy Sci. 84:1210-1217.
• Tumeo, M. A., K. F. Knowlton, and P.C. Bartlett  2000. Using risk assessment to manage environmental challenges on the farm. J. Amer. Vet. Med. Assoc. 217 (12): 7-10.
• Knowlton, K. F., T. E. Dawson, B. P. Glenn, G. B. Huntington, and R. A. Erdman. 1998. Glucose metabolism and milk yield of cows infused abomasally or ruminally with starch. J. Dairy Sci. 81:3248-3258.
• Knowlton, K. F., B. P. Glenn, and R. A. Erdman. 1998. Performance, rumen fermentation, and site of starch digestion in early lactation cows fed corn grain harvested and processed differently. J. Dairy Sci. 81: 1972-1984.
• Knowlton, K. F., M. S. Allen, and P. S. Erickson. 1996. Lasalocid and particle size of corn grain for dairy cows in early lactation. 1. Effect on performance, serum metabolites, and nutrient digestibility. J. Dairy Sci. 79:557.
• Knowlton, K. F., M. S. Allen, and P. S. Erickson. 1996. Lasalocid and particle size of corn grain for dairy cows in early lactation. 2. Effect on ruminal measurements and feeding behavior.  J. Dairy Sci. 79:565.
• Knowlton, K. F., R. E. Pitt and D. G. Fox. 1992. Dynamic model prediction of the value of reduced solubility of alfalfa silage protein for lactating dairy cows. J. Dairy Sci. 75:1507-1516.
• Knowlton, K. F., R. E. Pitt and D. G. Fox. 1992. Model-predicted nutritional and economic value of enzyme treated alfalfa silage for lactating dairy cows. J. Prod. Ag. 6: 280.

Book Chapter

• Z. Zhao, K. F. Knowlton and N. G. Love. 2008. Hormones in Waste from Concentrated Animal Feeding Operations. pp 292-329 In D. Aga (Ed.), Fate of Pharmaceuticals in the Environment and in Water Treatment Systems. CRC Press, Taylor and Francis Books.

• Knowlton, K. F. 2004. Review of "Minerals in Animal and Human Nutrition, 2nd edition". Poultry Sci. 83: 132.

• Pease, J., D. Bosch, M. L. Wolfe, J. Arogo Ogejo, C. Zobel, N. Franz, K. F. Knowlton, and G. Evanylo. 2008. Community DECISIONS: Community Decision Support for Integrated, On-the-ground Nutrient Strategies. USDA/CSREES National Water Conference, Feb. 3-7. Reno, NV
  
• Cox, B. G., R. E. James, K. F. Knowlton, M. L. McGilliard, and C. C. Stallings. 2007. Producer perceptions of feed management software. J. Dairy Sci. 90(Suppl. 1):64.
  
• Daniels, K. M., S. R. Hill, K. F. Knowlton, R. E. James, R. E. Pearson, M. L. McGilliard and R. M. Akers. 2007. Effects of milk replacer composition on selected blood metabolites and hormones in pre-weaned Holstein heifers. J. Dairy Sci. 90(Suppl. 1):84-85.
  
• Cox, B. G., R. E. James, K. F. Knowlton, M. L. McGilliard, and C. C. Stallings. 2007. Impact of feed management software on whole farm nutrient balance and feeding management. J. Dairy Sci. 90(Suppl. 1):123. 1st place presentation in Southern Regional ADSA Production Division graduate student competition.
  
• Taylor, M. S., K. F. Knowlton, M. L. McGilliard, W. S. Swecker Jr., J. D. Ferguson, and Z. Wu. 2007. Calcium and phosphorus balance and bone mobilization through lactation with varying dietary calcium. J. Dairy Sci. 90(Suppl. 1): 212.1st place presentation in National ADSA Production Division graduate student competition.
  
• Velayudhan, B. T., K. M. Daniels, M. L. McGilliard, B. Corl, K. F. Knowlton and R. M. Akers. 2007. Abundance of mRNA expression and nutritional regulation of somatotropic axis genes in the small intestine of prepubertal dairy heifers fed high-protein high-fat milk replaces. J. Dairy Sci. 90(Suppl. 1): 295.
• Hill, S. R., K. M. Daniels, K. F. Knowlton, R. E. James, R. E. Pearson, M. L. McGilliard and R. M. Akers. 2007. The effect of milk replacer composition on growth and body composition of Holstein heifer calves. J. Dairy Sci. 90(Suppl. 1): 297.
  
• Zhao, Z., K. F. Knowlton, and N. G. Love. 2007. Dairy Manure Estrogens with Advanced Treatments. 2007. J. Dairy Sci. 90(Suppl. 1):332.
  
• Taylor, M. S., K. F. Knowlton, M. L. McGilliard and J. H. Herbein. 2007. Blood mineral, hormone, and osteocalcin responses of multiparous Jersey cows to an oral dose of 25-hydroxyvitamin D3 prior to parturition. J. Dairy Sci. 90(Suppl. 1): 359.
  
• Fang, Y., Z. Zhao, N. G. Love, K. F. Knowlton and J. Novak. 2007. Detecting Endocrine Disrupting Compounds in Various Waste Matrices Water Environment Research Foundation Conference "Compounds of Emerging Concern: What's on the Horizon" (In press).
  
• Hill, S.R., K. F. Knowlton, E. Kebreab, J. France and M. D. Hanigan. 2007. A model of phosphorus digestion and metabolism in the lactating dairy cow. Can. J. Anim. Sci
  
• Zhao, Z., K. F. Knowlton, and N. G. Love. 2007. The removal of estrogens in different dairy manure treatments. Virginia Tech's Deans' Forum on the Environment. Blacksburg, VA. February 26, 2007, poster presentation. 1st place graduate student poster in "The Natural Environment" division.
  
• Gungor; K., J. Arogo Ogejo, K. F. Knowlton, and N. G Love. 2007. Biological phosphorus removal to produce "Designer Manures" for dairy farms. Virginia Tech's Deans' Forum on the Environment. Blacksburg, VA. February 26, 2007, poster presentation.
  
• Arogo Ogejo, J., K. Gungor, Z. Wen, Z. Hu, T. Yao, N. G. Love, and K. F. Knowlton. 2007. Recovery of phosphorus from dairy manure as struvite. Virginia Tech's Deans' Forum on the Environment. Blacksburg, VA. February 26, 2007, poster presentation.
  
• DeBusk, J., J. Arogo Ogejo, N. G. Love, and K. F. Knowlton. 2007. Adjusting N:P ratios in liquid dairy manure through nitrification and chemical phosphorus removal to match crop fertilizer requirements. Virginia Tech's Deans' Forum on the Environment. Blacksburg, VA. February 26, 2007, poster presentation.
  
• Beck, J., K. R. Gilmore, K. F. Knowlton, J. Arogo Ogejo, and N. G. Love. 2007. Nitrogen removal from dairy waste using deammonification fueled by fermented dairy manure. Virginia Tech's Deans' Forum on the Environment. Blacksburg, VA. February 26, 2007, poster presentation.
  
• Zhao, Z., K. F. Knowlton, N. G. Love, and Y. Fang. 2006. 17ß-Estradiol content of treated dairy manure. Virginia Water Science and Technology Symposium (in press).
• Powell, J. M., K. F. Knowlton, M. P. Russell, and M. D. Hanigan. 2006. Manure nitrogen transformations in air, soil and crops on dairy farms. J. Dairy Sci. 84 (Suppl. 1): 450.
• Hill, S. R., K. M. Daniels, K. F. Knowlton, R. E. James, R. E. Pearson, and R. M. Akers. 2006. Milk replacer composition and nutrient utilization in pre-weaned calves. J. Dairy Sci. 84 (Suppl. 1): 143.
• Yang, T. H., K. F. Knowlton, C. Shang, E. Schwab, D. Berry, L. Zelazny, N. Whitehouse, K. Pence, and C. Schwab. 2006. Dietary factors affecting phosphorus digestion in lactating cows. J. Dairy Sci. 84 (Suppl. 1): 224.
• Taylor, M. S., S. R. Hill, K. F. Knowlton, K. Wilson, and C. Cobb. 2006. Exogenous phytase plus cellulase and nutrient excretion and digestibility in lactating cows. J. Dairy Sci. 84 (Suppl. 1): 225.
• Hollmann, M., K. F. Knowlton, C. M. Parsons, M. D. Hanigan, and T. N. Rensch. 2006. Qualitative assessment of the irrigation water from separated and aerated flushed dairy manure. J. Dairy Sci. 84 (Suppl. 1): 355.
• Hollmann, M., K. F. Knowlton, C. M. Parsons, and T. N. Rensch. 2006. Daily manure production from a lactating cow facility. J. Dairy Sci. 84 (Suppl. 1): 260.
• Hollmann, M., K. F. Knowlton, C. M. Parsons, and T. N. Rensch. 2006. Chemical parameters, particle and nutrient removal with separation, settling, and aeration in flushed dairy manure. J. Dairy Sci. 84 (Suppl. 1): 355.
• Yang, T. H., K. F. Knowlton, C. Shang, J. A. Voelker-Linton, and M. S. Allen. 2006. Phosphorus digestion in lactating
  cows fed diets containing beet pulp. J. Dairy Sci. 84 (Suppl. 1): 441.
• Muftugil, M., Knowlton, K. F., and Love, N. G. 2005. Using enhanced biological phosphorus removal to minimize nutrient delivery from dairy farms to receiving waters. Water Environment Federation 78th Annual Conference and Exposition, Washington DC, Oct 31-Nov 2, 2005.
• Khunjar, W., Sweetman, P., Knowlton, K. F., Smets, B. F. and Love, N. G. 2005. Treatment of anaerobically stabilized dairy waste with an oxygen limited autotrophic nitrification plus denitrification (OLAND) fixed film reactor: startup and maintenance issues. AWWA/VWEA Joint Annual Meeting, Virginia Beach, Virginia, September 26-28, 2005.
• Muftugil, M., Knowlton, K. F., and Love, N. G. 2005. Using enhanced biological phosphorus removal to minimize nutrient delivery from dairy farms to receiving waters. AWWA/VWEA Joint Annual Meeting, Virginia Beach, Virginia, September 26-28, 2005.
• Muftugil, M. B., Love, N. G. and Knowlton, K. F. 2005. Using Enhanced Biological Phosphorus Removal (EBPR) to Alter the Nitrogen:Phosphorus Ratio of Dairy Manure and to Minimize Nutrient Delivery to Receiving Waters, Water Environment Federation Innovative Uses of Agricultural Wastes Conference, Chicago, IL, July 1-3, 2005.
• S. R. Hill, K. F. Knowlton, R. E. James, R. E. Pearson, G. Bethard, K. P. Pence, and S. W. Wilson. 2005. Manure production of heifers fed diets varying in forage, grain, and byproduct content. Journal of Dairy Sci. 88(Suppl.1):323.
• L. D. Hughes, K. F. Knowlton, N. G. Love, A. M. Gamboni, and C. M. Parsons. 2004. Wastewater treatment to reduce phosphorus losses from dairy farms. J. Dairy Sci. 87 (Suppl. 1): 470.
• K. F. Knowlton, J. M. McKinney, K. F. Wilson, and C. Cobb. 2003. Effect of an exogenous phytase enzyme blend and dietary phosphorus content on P excretion in lactating cows.
  J. Dairy Sci. 86 (Suppl. 1): 224.
• K. F. Knowlton. 2003. Animal management to reduce phosphorus losses to the environment.  J. Dairy Sci. 86 (Suppl. 1): 128.
• J. D. Toth, Z. Dou, J. D. Ferguson, R. J. Munson, L. E. Chase, K. F. Knowlton, R. A. Kohn, J. T. Sims, and Z. Wu. 2002. A phosphorus management survey on Northeast and Mid-Atlantic dairy farms in the U.S. J. Dairy Sci. 85.
• K. M. Burkholder, A. D. Guyton, J. M. McKinney, and K. F.  Knowlton. 2002. The effect of steam flaked or ground corn and supplemental phytic acid on N excretion in lactating cows and ammonia emission from manure. J. Dairy Sci. 85 (Suppl. 1): 148.
• A. D. Guyton, J. M. McKinney, and K. F. Knowlton. 2002. The effect of steam flaked or ground corn and supplemental phytic acid on ruminal phytase activity and P balance in lactating cows. J. Dairy Sci. 85 (Suppl. 1): 160.
• B. E. Keene, A. M. Rutledge, S. M Nickols-Richardson, C. Holtaway, J. M. McKinney and K.F. Knowlton. 2002. Estimating bone mineral content in dairy cows.   J. Dairy Sci. 85 (Suppl. 1): 160
• Z. Dou, K. F. Knowlton, G. Zhang, Z. Wu, and R.A. Kohn. 2001. Lowering dietary P in dairy rations reduces the vulnerable P fraction in manure J. Dairy Sci. 84 (Suppl. 1): 254.
• K. F. Knowlton, W. A. Wark, J. H. Herbein. 2000. Phosphorus balance throughout early lactation in dairy cows fed diets varying in phosphorus content. J. Dairy Sci. 83 (Suppl. 1): 303.
• A. Guyton, K. F. Knowlton, D. P. Casper, B. P. Glenn, and V. A. Wilkerson. 2000. Starch source affects phosphorus digestion and excretion by lactating dairy cows. J. Dairy Sci. 83 (Suppl. 1): 288.
• S. E. Sink, K. F. Knowlton, and J. H. Herbein. 2000. Economic and environmental implications of overfeeding phosphorus on Virginia dairy farms. J. Anim Sci. 78 (Suppl. 2): 4.
• F. P. Wydner, III, G. M. Jones, and K. F. Knowlton. 2000. Field implementation of nutrition and herd management practices to reduce nutrient losses from Shenandoah Valley dairy farms. J. Dairy Sci. 83 (Suppl. 1): 104.
• K. F. Knowlton, T. E. Dawson, K. L. Sarratt, Glenn, B. P. , and R. A. Erdman. 1997. Effect of long-term abomasal or ruminal starch infusion on milk yield and glucose metabolism of early lactation cows. J. Dairy Sci. 80: (Suppl. 1): 141.
• K. F. Knowlton, Glenn, B. P. , and R. A. Erdman. 1996. Effect of corn grain maturity and processing on performance, rumen fermentation, and site of starch digestion in early lactation dairy cattle. J. Dairy Sci. 79: (Suppl. 1): 138.
• Glenn, B. P., K. F. Knowlton, and V. A. Wilkerson. 1996. Intake and performance by lactating cows fed corn grain harvested as dry or high moisture and ground or rolled. J. Anim. Sci. 74: 87.
• Glenn, B. P., K. F. Knowlton, and D. P. Casper. 1995. Effect of forage and starch source on performance and rumen fermentation of early lactation dairy cows. J. Dairy Sci. 78: (Suppl. 1) 208.
• Knowlton, K. F., M. S. Allen, and P. S. Erickson. 1993. Effect of lasalocid and corn grain particle size on performance, feed digestibility, and rumen parameters in early lactation dairy cattle. J. Dairy Sci. 76: (Suppl. 1) 280.

• Knowlton, K. F. 2008. Dietary nutrient management: Where are we now? Virginia Veterinary Association annual meeting, Roanoke, VA. February 23, 2008.
• K. F. Knowlton. 2006. Implementing waste solutions for livestock and dairy farms. Environment Virginia Conference. Lexington, VA. April 20, 2006.
• G. Evanylo, K. F. Knowlton, S. Friedman, A. Jennings, and K. Holm. 2006. Animal agriculture and environmental solutions for the Shenandoah Valley. Research, Extension, and Education for Water Quality and Quantity. USDA-CSREES National Water Quality Conference. San Antonio, TX. Feb 5-9.
• K. F. Knowlton, N. G. Love and M. Muftugil. Wastewater treatment to reduce the phosphorus content of dairy manure. pp. 129-134 In Proceedings of the Virginia Tech Cow College, Blacksburg, VA. January 2005.
• S. R. Hill and K. F. Knowlton. Nitrogen and phosphorus retention, partition, and excretion in dairy heifers. pp. 135-140 In Proceedings of the Virginia Tech Cow College, Blacksburg, VA. January 2005.
• Knowlton, K. F. Dietary Nutrient Management: Feeding to meet environmental regulations. Animal Feed Technologies Dairy Nutrition Symposium, Garden City, KS. May 2004.
• Knowlton, K. F. Dietary nutrient management: Where are we now? Virginia State Feed Association annual meeting, Charlottesville, VA. February 2004.
• K. F. Knowlton. Nutrition to minimize the environmental impact of livestock farms. Department of Conservation and Recreation annual training for VPA permit holders. Roanoke, VA and Mt Crawford, VA. December 2003 and January 2004.
• K. F. Knowlton. Opportunities to reduce phosphorus losses from dairy operations. American Registry of Professional Animal Scientists, California chapter annual meeting. Coalinga, CA. October, 2003.
• K. F. Knowlton, J. S. Radcliffe, D. A. Emmerson, and C. L. Novak. Animal management to reduce phosphorus losses to the environment. American Dairy Science Association/American Society of Animal Science joint meetings, Phoenix, AZ. June 2003.
• K. F. Knowlton and A. D. Guyton. Nutrition and the Environment - ongoing research at Virginia Tech. Virginia Tech Cow College, Blacksburg, VA. January 2003.
• K. F. Knowlton. Nutrition to minimize the environmental impact of livestock farms. Department of Conservation and Recreation annual training for VPA permit holders. Culpeper, VA and Roanoke, VA. December 2002 and February 2003.
• K. F. Knowlton. Phosphorus-based regulations - the role of the feed company. Annual sales training meeting of Growers Nutritional Solutions, Milan, OH. December 2002.
• K. F. Knowlton. Dietary nutrient management for dairy farms. Mid-Atlantic Conference for Bovine Veterinary Practitioners. Frederick, MD. April 2002.
• W. J. Powers and K. F. Knowlton. Environmental issues affecting calf and heifer growers: What do you need to know? (slides or paper) pp 30-46 In Proceedings of the 2002 Dairy Calf and Heifer conference. Baltimore, MD. March 21-23, 2002.
• K. F. Knowlton.  High grain diets for dairy cattle.  Recent Advances in Animal Nutrition in Armidale, New South Wales, Australia. July 2001.
• K. F. Knowlton.  Forage Quality and Nutrient Utilization in Ruminants. Virginia State Feed Association Annual Feed Convention and Nutrition Conference, Williamsburg, VA. February 2001.
• K. F. Knowlton.  Reducing the environmental impact of farms: Is there a role for DHIA?  Presentation to the National DHIA/NALMA meetings; June 30, 2000; Montreal
• K. F. Knowlton.  Feeding management to reduce phosphorus losses from dairy farms. Virginia Tech Cow College, Blacksburg, VA. January 2000.
• K. F. Knowlton.  High moisture corn in dairy rations. Virginia Tech Cow College, Blacksburg, VA. January 2000.
• K. F. Knowlton and R. A. Kohn.  Feeding management to reduce phosphorus losses from dairy farms.  Mid-Atlantic Dairy Management Conference. Camp Hill, PA. February 1999.
• K. F. Knowlton. Reducing phosphorus losses from dairy farms through nutrition. Pennsylvania State University Department of Dairy and Animal Science, Departmental Seminar. State College, PA. February 1999.
• K. F. Knowlton. Ruminant nutrition and the environment. Virginia State Feed Association Annual Feed Convention and Nutrition Conference, Williamsburg, VA. February 1999.
• K. F. Knowlton. The Cornell Net Carbohydrate and Protein System: Purpose, prediction of nutrient requirements, and accuracy. Virginia Tech Cow College, Blacksburg, VA. January 1999.
• K. F. Knowlton. Corn silage hybrids with enhanced fiber digestibility. Virginia Tech Cow College, Blacksburg, VA. January 1999.
• K. F. Knowlton. Fiber digestibility: Opportunities and challenges. Shenandoah valley seed dealers and dairy farmers, Harrisonburg, VA. November 1998.
• K. F. Knowlton. More mileage from your silage: New corn hybrids for silage. Virginia Valley-Blue Ridge Forage Conference, Stuarts Draft, VA. February 1998.
• K. F. Knowlton. Environmental constraints on Virginia dairy farms. Virginia State Dairyman?s Association Annual Convention, Roanoke, VA. January 1998.
• K. F. Knowlton. Environmental implications of nutrition and feeding management. Virginia Tech Cow College, Blacksburg, VA. January 1998.
• K. F. Knowlton. Site of starch digestion in lactating cows.  Virginia Dairy Nutrition Council, Staunton, VA.  October 1997.
• K. F. Knowlton*, B. P. Glenn, V. A. Wilkerson, and R. A. Erdman. High moisture corn in lactating dairy cows rations: Digestion, metabolism, and production. Maryland Nutrition Conference for Feed Manufacturers, Baltimore, MD. March 1997.
• Glenn, B. P.*, K. F. Knowlton, V. A. Wilkerson, and T. E. Dawson. Energy metabolism and performance by early lactation Holstein cows fed corn grain harvested as dry or high moisture and ground or rolled. 47th Annual Meeting of the EAAP, Lillehammer, Norway.  August 1996.
• Allen, M. S.* and K. F. Knowlton. Non-structural carbohydrates in ruminant diets. American Feed Industry Association's Nutrition Institute, St. Louis, MO. November 1993.
• K. F. Knowlton, B. P. Glenn, and R. A. Erdman. High moisture corn in lactating cow rations: Digestion, metabolism and production. Cornell Nutrition Conference. Rochester, NY. October, 1999.

• Knowlton, K. F. Dietary nutrient management to reduce nutrient losses from dairy cows. Progressive Dairyman, 2008, 7: 26-27.
• Hill S.R., K. F. Knowlton, R. E. James, R. E. Pearson, K. J. Pence, and G. L. Bethard. Manure, nitrogen, and phosphorus excretion in gravid dairy heifers. Feedinfo News Service Scientific Reviews. May 2008. Available from URL: http://www.feedinfo.com.
• Zhao, Z. and K. F. Knowlton. Dairy at-a-glance in China. The Virginia Dairyman, 2008.
• Zhao, Z. and K. F. Knowlton. Dietary Cation-Anion Balance and Milk Fever Control in Dairy Cows. Virginia Dairyman, 2006, 70(3):13.
• Marstaller, C. and K. F. Knowlton. How Virginia is tackling environmental challenges. Hoards Dairyman, 2007, 52: 521.
• Knowlton, K. F., M. D. Hanigan and C. C. Stallings. Reducing phosphorus losses from dairy farms. Progressive Dairyman, 2007, 21 (5): 10-13.
• R. Johnson and K. F. Knowlton. Working toward nutrient balance. Hoards Dairyman, 2004, 149(8): 290.
• Knowlton, K. F. Your top five environmental questions answered. The Jersey Journal, 2004, 51(4): 36-37.
• Knowlton, K. F. Why are we still overfeeding phosphorus? Hoards Dairyman, 2004, 148: 725.
• Knowlton, K. F. New federal CAFO regulations. The Jersey Journal, 2003, 50(4): 42-43.
• Knowlton, K. F. Environmental programs in the new farm bill. The Jersey Journal, December 2002, 49: 36-37.
• Knowlton, K. F. Do you have an animal waste spill response plan? The Jersey Journal, August 2002, 49:63.
• Jones, G. M. and K. F. Knowlton. Nutrition and Herd Management to reduce nutrient losses from dairy farms. The Virginia Dairyman, July 2002, pp. 21-23.
• Knowlton, K. F. New phosphorus requirements: Opportunity to reduce excretion. The Jersey Journal, May 2002, 49: 106, 108.
• Knowlton, K. F. Proposed changes to federal environmental regulations.  The Jersey Journal, February 2002, 49: 45, 48.
• Knowlton, K. F. Federal environmental regulations under a new administration.The Jersey Journal, November 2001, 48: 63.
• Knowlton, K. F. TMDLs: Here to stay. The Jersey Journal, April 2001, 48: 61-62.
• Knowlton, K. F. Should dairy producers help develop legislation? The Jersey Journal, January 2001, 48: 57-58.
• Knowlton, K. F., B. P. Glenn, R. A. Erdman, and V. A. Wilkerson. The high moisture corn advantage: Greater than we thought. Hoards Dairyman, October 25, 2000, p. 728.
• Knowlton, K. F. Ammonia emissions: the next regulatory hurdle. The Jersey Journal, October 2000, 47: 56-57.
• Guyton, A. D.  and K. F. Knowlton. Animal agriculture and the environment: Starch source affects phosphorus excretion by dairy cows. The Virginia Dairyman, September 2000,
  pp. 21-22.
• Knowlton, K. F. Herd management to reduce nutrient losses. The Jersey Journal, July 2000, 47: 43, 46.
• Knowlton, K. F. and W. J. Powers. Dairy odors don't need to be repulsive. Hoards Dairyman, May 25, 2000, p. 375.
• Knowlton, K. F. and T. S. Haley. Animal agriculture and the environment: Do you need a VPA permit? The Virginia Dairyman, May 2000, pp. 36-37.
• Knowlton, K. F. Reducing phosphorus losses through nutrition. The Jersey Journal, April 2000, 47: 92-93.
• Knowlton, K. F. Reducing nitrogen losses through nutrition. The Jersey Journal, January 2000, 47: 80-81.
• Knowlton, K. F. Are Jerseys part of the answer? The Jersey Journal, January 2000, 47: 81.
• Knowlton, K. F. Animal agriculture and the environment: Phosphorus requirements of lactating cows. Farmshine, December 17, 1999, pp. 32, 41.
• Knowlton, K. F., R. A. Erdman, and B. P.Glenn. Corn processing influences more than starch digestion. Feedstuffs, December 13, 1999, vol. 71 pp. 11-13.
• Knowlton, K. F. and C. Leubben. Animal agriculture and the environment: TMDLs: Here to stay. The Virginia Dairyman, December 1999, pp. 136-37.
• Knowlton, K. F. Dairy farming and the environment: Areas of concern: Odor control during manure storage.  American Dairy Farmer, December 1999, p. 12.
• Knowlton, K. F. Dairy farming under environmental regulations. The Jersey Journal, October 1999, p. 66.
• K. F. Knowlton, B. P. Glenn, and R. A. Erdman. High moisture corn in lactating cow rations: Digestion, metabolism and production. Cornell Nutrition Conference. Rochester, NY. October, 1999.
• Knowlton, K. F.  Dairy farming and the environment: Areas of concern: Phosphorus. American Dairy Farmer, October 1999, p. 13.
• Knowlton, K. F., and S. Sink. Animal agriculture and the environment: Overfeeding increases feed costs, and reduces your ability to survive environmental regulations.  The Virginia Dairyman, September 1999, p. 10, 12.
• Knowlton, K. F.  Dairy farming and the environment: Areas of concern: Nitrogen. American Dairy Farmer, September 1999, pp. 32, 34.
• K. F. Knowlton. Dairy farming under environmental regulations. New York State Holstein News, September 1999, pp. 28, 51.
• Knowlton, K. F., and S. C. Sink.  Animal agriculture and the environment: Are Virginia dairy farmers overfeeding phosphorus?  The Virginia Dairyman, August 1999, pp. 38, 42.
• Jones, G. M., Knowlton, K. F., and B. Clark.  Are There Alternatives to Fencing the Dairy Herd Out of Streams? The Virginia Dairyman.  August 1999, pp. 24-26.
• Knowlton, K. F. and R. A. Kohn. We've got to stop overfeeding phosphorus.  Hoards Dairyman, June 1999, p. 437.
• Knowlton, K. F.  Animal agriculture and the environment: Meeting the new VPA permit requirements.  The Virginia Dairyman, June 1999, pp. 16-17.
• Jones, G. M. and K. F. Knowlton. Protecting healthy streams by fencing out the dairy herd. The Virginia Dairyman, May 1999, p 14.
• Knowlton, K. F., R. Kohn, and J. Jonker. Animal agriculture and the environment: Milk urea nitrogen, protein utilization, and water quality. The Virginia Dairyman, 04\1999, p 27-28.
• Knowlton, K. F. and R. A. Kohn. Altering rations may reduce phosphorus losses. Feedstuffs, April 12, 1999, vol. 71 pp. 12-15, 27.
• Knowlton, K. F. Animal agriculture and the environment: Reducing odors on dairy farms. Farmshine, March 26, 1999, pp. 31, 40.
• Knowlton, K. F. Animal agriculture and the environment: Phosphorus requirements of lactating cows. The Virginia Dairyman, January 1999, p 14.
• Knowlton, K. F. Animal agriculture and the environment: Virginia?s Agricultural Stewardship Act. Farmshine, December 18, 1998, p. 16.
• Knowlton, K. F. Animal agriculture and the environment: A role for Dairy Producers in Developing Agricultural Legislation. Farmshine, December 11, 1998, p. 15, 28.
• Knowlton, K. F. and G. M. Jones. Animal agriculture and the environment: The EPA and USDA?s draft strategy for animal feeding operations. The Virginia Dairyman, November 1998, pp.1 & 12.
• Knowlton, K. F. Animal agriculture and the environment: Should the dairy industry help develop environmental legislation? The Virginia Dairyman, September 1998, p. 16.
• Knowlton, K. F. and J. H. Herbein. Animal agriculture and the environment: Role of nutrition in reducing nitrogen losses. Farmshine, August 7, 1998, p. 19.
• Knowlton, K. F. Animal agriculture and the environment: Industry involvement in environmental policy development. The Virginia Dairyman, July 1998, p. 30-31.
• Knowlton, K. F. and J. H. Herbein. Animal agriculture and the environment: The Virginia Agricultural Stewardship Program. The Virginia Dairyman, June 1998, p. 14.
• Knowlton, K. F. and J. H. Herbein. Animal agriculture and the environment: Reducing phosphorus losses through nutrition. The Virginia Dairyman, May 1998, pp. 35-36.
• Knowlton, K. F. and J. H. Herbein. Animal agriculture and the environment. Farmshine, April 24, 1998, p. 13.
• Knowlton, K. F. and J. H. Herbein. Animal agriculture and the environment: Reducing nitrogen losses through nutrition. The Virginia Dairyman, April 1998, p. 22.
• Knowlton, K. F. and J. H. Herbein. Animal agriculture and the environment: Herd management to reduce nutrient losses. The Virginia Dairyman, February 1998, p. 1.
• Knowlton, K. F.  More mileage from your silage: New corn silage hybrids in dairy rations. The Virginia Dairyman, February 1998, p. 36.
• Knowlton, K. F. and J. H. Herbein. Animal agriculture and the environment inseparable. Farmshine, February 6, 1998, p. 16.
• Knowlton, K. F. and J. H. Herbein. How can you keep odors to acceptable levels? Farmshine, February 6, 1998, p. 23.
• Knowlton, K. F. and J. H. Herbein. Animal agriculture and the environment: Odor control during spreading. The Virginia Dairyman, January 1998, p. 43.
• Knowlton, K. F. and J. H. Herbein. Animal agriculture and the environment:  Odor control during storage. The Virginia Dairyman, December 1997, p. 16.
• Knowlton, K. F. and J. H. Herbein. Animal agriculture and the environment: Odors. The Virginia Dairyman, November 1997, p. 42.
• Knowlton, K. F. and J. H. Herbein. Animal agriculture and the environment: Areas of concern: Phosphorous. The Virginia Dairyman, October 1997, p. 42.
• Knowlton, K. F. and J. H. Herbein. Animal agriculture and the environment: Areas of concern: Nitrogen. The Virginia Dairyman, September 1997, p. 62.
• Knowlton, K. F. and J. L. Majeskie. Animal rights, animal welfare, and you; Be prepared to answer questions at the fair. Hoards Dairyman, June 1995, p. 449.
• Allen, M. S. and K. F. Knowlton. Non-structural carbohydrates important to ruminants.  Feedstuffs, April 17, 1995,  pp. 13-15.
• Knowlton, K. F., M. S. Allen, and C. A. Rotz. When silage inoculants are needed. Hoards Dairyman, September 10, 1992, pp. 606-607.