Ali, C. S., T. Khaliq and M. Sarwar. 1997. Influence of various sources of non-protein nitrogenous sources on in vitro fermentation patterns of rumen microbes. J. Anim. Feed Sci. Teclmol. 10:353-363.
Association of Official Analytical Chemists. 1990. Official Methods of Analysis (15Th Ed.) Arlington, Virginia, USA.
Broderick, G. A. and M. K. Clayton. 1997. A statistical evaluation of animal and nutritional factors influencing concentrations of milk urea nitrogen. J. Dairy Sci. 80:2964-2970.
Butler, W. R. 1998. Review: Effect of protein nutrition on ovarian and uterine physiology in dairy cattle. J. Dairy Sci. 81:2533-2539.
Castillo, A. R., E. Kebreab, D. E. Beever, J. H. Barbi, J. D. Sutton, H. C. Kirby and F. France. 2001. The effect of protein supplementation on nitrogen utilization in lactating dairy cows fed grass silage diets. J. Anim. Sci. 79:247-253.
Chaturvedi, O. H. and T. K. Walli. 2001. Effect of feeding graded levels of undegraded dietary protein on voluntary intake, milk production and economic return in early lactating crossbred cows. Asian-Aust. J. Anim. Sci. 14: 1118-1124.
Chumpawadee, S., K. Sommart, T. Vongpralub and V. Pattarajinda. 2006. Effects of synchronizing the rate of dietary energy and nitrogen release on ruminal fermentation, microbial protein synthesis, blood urea nitrogen and nutrient digestibility in beef cattle. Asian-Aust. J.Anim. Sci. 19:181-188.
Clark, J. H. 1975. Lactational responses to postruminal administration of protein and amino acids. J. Dairy Sci. 58: 1178-1197.
Davidson, S., B. A. Hopkins, D. E. Diaz, S. M. Bolt, C. Brownie, V. Fellner and L. W. Whitlow. 2003. Effects of amounts and degradability of dietary protein on lactation, nitrogen utilization, and excretion in early lactation Holstein cows. J. Dairy Sci. 86:1681-1689.
Dhali, A., R. K. Mehla and S. K. Sirohi. 2005. Effect of urea supplemented and urea treated straw based diet on milk urea concentration in crossbred karan-fries cows. Italian J. Anim. Sci. 4:25-34.
Dhali, A., D. P. Mishra, R. K. Mehla and S. K. Sirohi. 2006. Usefulness of milk urea concentration to monitor the herd reproductive performance in crossbred karan-fries cows. Asian-Aust. J. Anim. Sci. 19:26-30.
Dhiman, T. R. and L. D. Satter. 1997. Effect of rum in ally degraded protein on protein available at the intestine assessed using blood amino acid concentrations. J. Anim. Sci. 75: 1674-1680.
Flis, S. A. and M. A. Wattiaux. 2005. Effects of parity and supply of rumen-degraded and undegraded protein on production and nitrogen balance in Holsteins. J. Dairy Sci. 88:2096-2106.
Griswold, K. E, G. A. Apgar, J. Bouton and J. L. Firkins. 2003. Effects of urea infusion and ruminal degradable protein concentration on microbial growth, digestibility, and fermentation in continuous culture. J. Anim. Sci. 81 :329-336.
Gulati, S.K., M. R. Garg and T. W. Scott. 2005. Rumen protected protein and fat produced from oil seeds and meals by formaldehyde treatment; their role in ruminant production and product quality: A review. Aust. J. Exp. Agric. 45: 1189-1203.
Guo, K., E. R.Cohen, M. A. Varner and R. A. Kohn. 2004. Effects of milk urea nitrogen and other factors on probability of conception of dairy cows. J. Dairy Sci. 87: 1878-1885.
Gustafassan, A.H. and J. Carlson. 1993. Effects of silage quality, protein evaluation systems and milk urea content on milk yield and reproduction in dairy cows. Livest. Prod. Sci. 37:91-105.
Haddad, S. G., R. T. Kridli and D. M. AI-Wali. 2005. Influence of varying levels of dietary undegradable intake protein on nutrient intake, body weight change and reproductive parameters in postpartum Awassi Ewes. Asian-Aust. J. Anim. Sci. 18:637-642.
Hoover, W. H. and T. K. Miller. 1990. Carbohydrate and protein considerations in ration formulation. Page 71 in Proc. Large Dairy Herd Manage. Conf., Cornell Coop. Ext., Cornell Univ., Ithaca, NY.
Jonker. J. S., R. A. Kohn and R. A. Erdman. 1998. Using milk urea nitrogen to predict nitrogen excretion and utilization efficiency in lactating dairy cows. J. Dairy Sci. 81:2681-2692.
Kalbande, V. H. and A. H. Chainpure. 2001. Effect of feeding bypass protein with urea treated jowar kadbi on performance of cross bred calves. Asian-Aust. J. Anim. Sci. 14:651-654.
Kalscheur, K. F., R. L. Baldwin, B. P. Glenn and R. A. Kohn. 2006. Milk production of dairy cows fed differing concentrations of rumen-degraded protein J. Dairy Sci. 89:249-259.
Koenig, K. M. and L. M. Rode. 2001. Ruminal degradability, intestinal disappearance, and plasma methionine response of rumen-protected methionine in dairy cows. J. Dairy Sci. 84: 1480-1487.
Kridli, R. T., S. G. Haddad and M. M. Muwalla. 2001. The effect of feeding ruminally undegradable protein on postpartum reproduction of Awassi Ewes. Asian-Aust. J. Anim. Sci. 14: 1125-1128.
Lee, M., S. Hwang and P. W. Chiou. 2001. Application of rumen undegradable protein on early lactation dairy goats. Asian-Aust. J.Anim. Sci. 14:1549-1554.
National Research Council. 1989. Nutrient requirements of dairy cattle (6th Rev. Ed.) National Academy Press, Washington, DC.
National Research Council. 2001. Nutrient requirements of dairy cattle. Seventh revised edition. National Academy Press, Washington, DC.
Nisa, M., M. A. Khan, M. Sarwar, W. S. Lee, S. B. Kim, B. S. Ahn and S. M. Kim. 2006. Influence of corn steep liquor on feeding value of urea treated wheat straw in buffaloes fed at restricted diets. Asian-Aust. J. Anim. Sci. 19: 1610-1619.
Nisa, M., M. Sarwar and M. A. Khan. 2004. Influence of ad libitum feeding of urea treated wheat straw with or without corn steep liquor on intake, in situ digestion kinetics, nitrogen metabolism, and nutrient digestion in Nili-Ravi buffalo bulls. Aust. J. Agric. Res. 55:235-342.
Nousiainen, J., K. J. Shingfield and P. Huhtanen. 2004. Evaluation of milk urea nitrogen as a diagnostic of protein feeding. J. Dairy Sci. 87:386-398.
Oba, M., R. L. Baldwin, S. L. Owens and B. J. Bequette. 2004. Urea synthesis by ruminal epithelial and duodenal mucosal cells from growing sheep. J. Dairy Sci. 87:1803-1805.
Oltner, R., M. Emanuelson and H. Wiktorsson. 1983. Page 195 in Factors affecting the urea concentration in cows milk. Proc. 5th Int. Conf. Rod. Dis. Farm Anim. Swed. Univ. Agric. Sci., Uppsala, Sweden.
Paengkoum, P., J. B. Liang, Z. A. Jelan and M. Basery. 2004. Effects of ruminally undegradable protein levels on nitrogen and phosphorus balance and their excretion in Saanen goats fed oil palm fronds. Songklanakarin J. Sci. Tehnol. 26: 15-22.
Pattanaik, A. K., V. R. B. Sastry, R. C. Katiyar and L. Murari. 2003. Influence of grain processing and dietary protein degradability on N metabolism, energy balance and methane production in young calves. Asian-Aust. J. Anim. Sci. 16: 1443-1450.
Petit, H. V. and D. M. Veira. 1991. Effect of grain level and protein source on rumimal fermentation, degradability and digestion in milking cows fed silage. Dairy Sci. 74:2256-2267.
Reynal, S. M. and G. A. Broderick. 2005. Effect of dietary level of rumen-degraded protein on production and nitrogen metabolism in lactating dairy cows. J. Dairy Sci. 88:4045-4064.
Roseler, D. K., J. D. Ferguson, C. J. Sniffen and J. Herrema. 1993. Dietary protein degradability effects on plasma and milk urea nitrogen and milk non-protein nitrogen in Holstein cows. J. Dairy Sci. 76:525-534.
Santos, F. A. P., J. E. P. Santos, C. B. Theurer and J. T. Hubber. 1998. Effects of rumen degradable protein on dairy cow performance: A 12-year literature review. J. Dairy Sci. 81: 3182-3213.
Sartin, J. L., K. A. Cummins, R. J. Krernpainen, D. N. Marple, C. H. Rahe and J. C. William. 1985. Glucagon, insulin and GH responses to glucose infusion in lactating cows. Nutr. Abstr. Rev. (Series B) Abstract No. 4371.
Sarwar, M., M. A. Khan and Z. Iqbal. 2002. Feed Resources for Livestock in Pakistan. Status Paper. Ind. J. Agric. Biol. 4: 186-192.
Sarwar, M., M. A. Khan and M. Nisa. 2004a. Influence of ruminally protected fat and urea treated corncobs on nutrient intake, digestibility, milk yield and its composition in Nili-Ravi buffaloes. Asian-Aust. J. Anim. Sci. 17:171-178
Sarwar, M., M. A. Khan and M. Nisa. 2004b. Effect of organic acids or fermentable carbohydrates on digestibility and nitrogen utilization of urea treated wheat straw in buffalo bulls. Aust. J. Agric. Res. 55:229-235.
Sarwar, M., M. A. Khan and M. Nisa. 2005.Chemical composition and feeding value of urea treated corncobs ensiled with additives for sheep. Aust. J. Agric. Res. 65:685-690.
Shahzad, M. A., M. Sarwar and M. Nisa. 2008. Influence of altering dietary cation anion difference on milk yield and its composition of early lactating Nili Ravi buffaloes in summer. Livest. Sci.113:133-143.
Schepers, A. J. and R. G. M Meijer. 1998. Evaluation of the utilization of dietary nitrogen by dairy cows based on urea concentration in milk. J. Dairy Sci. 81:579-584.
Sklan, D. and M. Tinsky. 1993. Production and reproduction responses by dairy cows fed varying undegradable protein coated with rumen bypass fat. J. Dairy Sci. 76:216-223.
SPSS, 1999. SPSS use's guide: Release 10.0.1 edition. SPSS Inc.
Staples, C. R., C. M. Garcia-Bojalil, B. S. Oldick, W. W. Thatcher and C. A. Risco. 1993. Protein intake and reproductive performance of dairy cows: a review, a suggested mechanism and blood and milk urea measurements. Pages 37-51 in Proc. 4th Annu. Florida Ruminant Nutr. Symp., Univ. Florida, Gainesville.
Titgemeyer, E. C., N. R. Merchen and L. L. Berger. 1989. Evaluation of soybean meal, corn gluten meal, blood meal and fish meal as sources of nitrogen and amino acids disappearing from the small intestine of steers. J. Anim. Sci. 67:262-273.
Van Soest, P. J., J. B. Robertson and B. A. Lewis. 1991. Methods for dietary fiber, neutral detergent fiber and non-starch polysaccharides in relation to animal nutrition. J. Dairy Sci. 74: 3583-3597.
Vestweber, J. G. E., F. K. AI-Ani and D. E. Johnson. 1989. Udder edema in cattle: effects of diuretics on serum and urine electrolytes. Am. J. Vet. Res. 50: 1323-1328.
Vongsamphan, P. and M. Wanapat. 2004. Effect of levels of cassava hay (CH) supplementation in native beef cattle feed on rice straw. In: Proceeding of the Agricultural Seminar, Animal Science/animal husbandry. Held at Sofitel Rajaorcid hotel 2728 January 2004, pp. 255-270.
Wanapat, M. and O. Pimpa. 1999. Effect of ruminant NH3-N levels on ruminant fermentation, purine derivatives, digestibility and rice straw intake in swamp buffaloes. AsianAust. J. Anim. Sci. 12:904-907.
Westwood, C. T., I. T. Lean, J. K. Garvin and P. C. Wyun. 2000. Effect of genetic merit and varying dietary protein degradability on lactating dairy cows. J. Dairy Sci. 83:2926-2940.
Wiley, J. S., M. K. Peterson, R. P. Ansotegui and R. A. Bellows. 1991. Production from first-calf heifers fed a maintenance or low level of prepartum nutrition and ruminally undegradable or degradable protein postpartum. J. Anim. Sci. 69:4279-4293.
Wilson, G., F. A. Martz, J. R. Campbell and B. A. Becher. 1975. Evaluation of factors responsible for reduced voluntary intake of urea diets for ruminants. J. Anim. Sci. 41: 1431-1439.