Association of official Analytical Chemists (1984) Official Methods of Analysis, 14th ed. Washington, DC: AOAC.
Baird, G. D., Lomax, M. A., Symonds, H. W. & Shaw, S. R. (1980) Net hepatic and splanchnic metabolism of lactate, pyruvate and propionate in dairy cows in vivo in relation to lactation and nutrient supply. Biochemical Journal 186, 47–57.
Bergman, E. N. (1990) Energy contributions of volatile fatty acids from the gastrointestinal tract in various species. Physiological Reviews 70, 567–590.
Bergman, E. N. & Pell, J. M. (1984) Integration of amino acid metabolism in the ruminant. In Herbivore Nutrition in the Tropics and Subtropics, pp. 613–428 [Gilchrist, F.M. C. and Mackie, R. I., editors]. Craighall, South Africa: The Science Press.
Burrin, D. G., Ferrell, C. L., Eisemann, J. H. & Britton, R. A. (1991) Level of nutrition and splanchnic metabolite flux in young lambs. Journal of Animal Science 69, 1082–1091.
Chase, C. C. & Hibberd, C. A. (1987) Utilization of low-quality native grass hay by beef cows fed increasing quantities of corn grain. Journal of Animal Science 65, 557–566.
Demign´, C., Yacoub, C., Morand, C. & Rémésy, C. (1991) Interactions between propionate and amino acid metabolism in isolated sheep hepatocytes. British Journal of Nutrition 65, 301–317.
Eisemann, J. H. & Nienaber, J. A. (1990) Tissue and whole-body oxygen uptake in fed and fasted steers. British Journal of Nutrition 64, 39—411.
Elliot, J. M. (1980) Propionate metabolism and vitamin B12. In Digestive Physiology and Metabolism in Ruminants, pp. 485–503 [Ruckebusch, Y. and Thivend, P., editors]. Westport, CT: AVI Publishing Co.
Ferrell, C. L., Britton, R. A. & Freetly, H. C. (1992) Chronic catheterization of hepatic and portal veins of sheep. In Handbook of Methodr for Study of Reproductive Physiology in Domestic Animals, Section VIII A & F. [Dziuk, P and Wheeler, M., editors]. Urbana, IL: University of Illinois.
Ferrell, C. L., Koong, L. J. & Nienaber, J. A. (1986) Effect of previous nutrition on body composition and maintenance energy costs of growing lambs. British Journal of Nutrition 56, 595–605.
Galloway, D. L. Sr, Goetsch, A. L., Forster, L. A. Jr, Patil, A. R., Sun, W. & Johnson, Z. B. (1993) Feed intake and digestibility by cattle consuming bermudagrass or orchardgrass hay supplemented with soybean hulls and(or) corn. Journal of Animal Science 71, 3087–3095.
Goering, H. K. & Van Soest, P. J. (1970) Forage Fiber Analyses. Apparatus, Reagents, Procedures and Some Applications. Agricultural Handbook no. 379. Washington, DC: ARS, USDA.
Grigsby, K. N., Kerley, M. S., Paterson, J. A. & Weigel, J. C. (1993) Combinations of starch and digestible fiber in supplements for steers consuming a low-quality bromegrass hay diet. Journal of Animal Science 71, 1057–1064.
Gross, K. L., Harmon, D. L., Minton, J. E. & Avery, T. B. (1990) Effects of isoenergetic infusions of propionate and glucose on portal-drained visceral nutrient flux and concentrations of hormones in lambs maintained by total intragastric infusion. Journal of Animal Science 68, 2566–2574.
Hall, K. L., Goetsch, A. L., Landis, K. M., Forster, L. A. Jr & Brake, A. C. (1990) Effects of a fat and ground maize supplement on feed intake and digestion by cattle consuming bermudagrass hay (Cynodon dactylon). Animal Feed Science and Technology 30, 275–288.
Harmon, D. L., Gross, K. L., Kreikemeier, K. K., Coffey, K. P., Avery, T. B. & Klindt, J. (1991) Effects of feeding endophyt-einfected fescue hay on portal and hepatic nutrient flux in steers. Journal of Animal Science 69, 1223–1231.
Harmon, D. L., Kreikemeier, K. K. & Gross, K. L. (1993) Influence of addition of monensin to an alfalfa hay diet on net portal and hepatic nutrient flux in steers. Journal of Animal Science 71, 218–225.
Highfill, B. D., Boggs, D. L., Amos, H. E. & Crickman, J. G. (1987) Effects of high fiber energy supplements on fermentation characteristics and in vivo and in situ digestibiltieses of low quality fescue hay. Journal of Animal Science 65, 224–234.
Huntington, G. B. & Reynolds, C. P. (1987) Oxygen consumption and metabolite flux of bovine portal-drained viscera and liver. Journal of Nutrition 117, 1167–1172.
Janes, A. N., Weekes, T. E. C. & Armstrong, D. G. (1985 a) Absorption and metabolism of glucose by the mesenteric-drained viscera of sheep fed on dried-grass or ground, maize-based diets. British Journal of Nutrition 54, 449–458.
Janes, A. N., Weekes, T. E. C. & Armstrong, D. G. (1985 b) Insulin and glucose metabolism in sheep fed on dried-grass or ground, maize-based diets. British Journal of Nutrition 54, 459–471.
Johnson, D. E., Johnson, K. A. & Baldwin, R. L. (1990) Changes in liver and gastrointestinal tract energy demands in response to physiological workload in ruminants. Journal of Nutrition 120, 649–655.
Landis, K. M., Goetsch, A. L., Forster, L. A. Jr & Brake, A. C. (1989) Sites of digestion in beef steers fed bermudagrass hay and supplemented with high-nitrogen feeds alone or with tallow. Archives of Animal Nutrition 40, 387–401.
Lindsay, D. B. (1993) Making the sums add up - the importance of quantification in nutrition. Australian Journal of Agricultural Research 44, 479–493.
Martin, S. K. & Hibberd, C. A. (1990) Intake and digestibility of low-quality native grass hay by beef cows supplemented with graded levels of soybean hulls. Journal of Animal Science 68, 4319–4325.
McCollum, F. T. & Horn, G. W. (1990) Protein supplementation of grazing livestock: a review. Professional Animal Scientist 6, 1–6.
McLean, J. A. (1972) On the calculation of heat production from open-circuit calorimetric measurements. British Journal of Nutrition 27, 597–600.
Mineo, H., Yasuda, T., Akiyama, M., Oyamada, T., Kato, S. & Ushijima, J. (1991) Effect of feeding on hepatic and portal blood flow in sheep. Small Ruminant Research 5, 181–186.
National Research Council (1984) Nutrient Requirements of Beef Cattle, 6th ed. Washington, DC: National Academy Press.
Reynolds, C. K., Huntington, G. B., Tyrrell, H. F. & Reynolds, P. J. (1988) Net metabolism of volatile fatty acids, D-beta-hydroxybutyrate, nonesterified fatty acids, and blood gases by portal-drained viscera and liver of lactating Holstein cows. Journal of Dairy Science 71, 2395–2405.
Statistical Analysis Systems (1985) SAS User's Guide: Statistics. Cary, NC: SAS Institute, Inc.
van derWalt, J. G. Walt, J. G. (1993) Nitrogen metabolism of the ruminant liver. Australian Journal of Agricultural Research 44, 381–403.
Webb, K. E. Jr & Bergman, E. N. (1991) Amino acid and peptide absorption and transport across the intestine. In Physiological Aspects of Digestion and Metabolism in Ruminants, pp. 111–128 [Tsuda, T., Sasaki, Y. and Kawashima, R., editors]. New York: Academic Press.
Weekes, T. E. C. (1991) Hormonal control of metabolism. In Physiological Aspects of Digestion and Metabolism in Ruminants, pp. 183–200 [Tsuda, T., Sasaki, Y and Kawashima, R., editors]. New York: Academic Press.
Williamson, D. H. & Mellanby, J. (1974) D-(β)-3-Hydroxybutyrate. In Methods of Enzymatic Analysis, Vol. 4, pp. 1836–1839 [Bergmeyer, H. editor]. New York: Academic Press.
Yen, J. T., Nienaber, J. A., Hill, D. A. & Pond, W. G. (1991) Potential contribution of absorbed volatile fatty acids to whole-animal energy requirement in conscious swine. Journal of Animal Science 69, 2001–2012.