1. AOAC., 1995. Official Methods of Analysis, 16th ed. Association of Official Analytical Chemists. Arlington, VA, USA.
2. AOAC., 2005. Official Methods of Analysis, 18th ed. Association of Official Analytical Chemists. Arlington, VA, USA
3. Arif, M., Sarwar, M., Hayat, Z. and Younas, M., 2016. Effect of supplementary sodium nitrate and sulphur on methane production and growth rates in sheep and goats fed forage based diet low in true protein. Journal of Animal and Plant Science, 26, 69-78.
4. Chalupa, W., 1977. Manipulating rumen fermentation. Journal of Animal Science, 46, 585-599.
5. Cherdthong, A., Wanapata, M., Wongwungchuna, W., Yeekeng, S., Nilthoa, T., Rakwongrit D., Khota, W., Khantharin, S., Tangmutthapattharakun, G., Phesatcha, K., Foiklang, S., Kang, S., Anantasook, N. and Gunun, P., 2014. Effect of feeding feed blocks containing different levels of urea calcium sulphate mixture on feed intake, digestibility and rumen fermentation in Thai native beef cattle fed on rice straw. Animal Feed Science and Technology, 198, 151-157.