Internat. J. of Sci. and Eng., Vol. 4(2)2013:86-91, April 2013, Hamdi Mayulu et al. 86 © IJSE – ISSN: 2086-5023, 15 th April, 2013, All rights reserved International Journal of Science and Engineering (IJSE) Home page: http://ejournal.undip.ac.id/index.php/ijse Intake and Digestibility of Cattle’s Ration on Complete Feed Based-On Fermented Ammonization Rice Straw with Different Protein Level Hamdi Mayulu 1) , Sunarso 2) , M. Christiyanto 2) and F. Ballo 3) Email: mayoeloehsptno@yahoo.com 1) Mulawarman University,Kampus Gunung Kelua Jl.Kuaro Samarinda, Indonesia 2) Diponegoro University, Kampus drh.Soejono Koesoemowardoyo Semarang Indonesia 3) SPPN Kupang, Jl.Timor Raya Km 39 Lili Kupang Indonesia Abstract - Complete feed (CF) utilization is expected to have impact on higher productivity due to increased intake and digestibility. The objective of research was to evaluate the effects of different level protein of CF based-on fermented ammonization (amofer) rice straw to Simmental offspring intake and digestibility Twenty males Simmental offspring with average live weight 372.15– 26.64 kg (coefficient of variance 7.16%) were used in this study. Feed treatment consisted of BC Nutrifeed 132 concentrate as control feed (T0) and CF based-on amofer rice straw consisted of T1, T2, T3 and T4 which had crude protein content 11, 12, 13 and 14% respectively and also total digestible nutrients (TDN) – 62%. Completely randomized design with five treatments and four replicates were designed for this research. Data was analyzed by analysis of variance (ANOVA) at 95% significance level. The results showed that different crude protein did not affect the intake of dry matter, organic matter, crude protein and TDN. It was significantly affected the digestibility of dry matter, organic matter and crude protein (p<0.01). The highest digestibility was obtained to treatment with 12% crude protein and – 62% TDN. Conclusion of this study was different level of crude protein constituted in CF which produced from specific material resource was proven to have impact in increasing cattle’s digestibility. Keywords — complete feed; fermented ammonization rice straw; intake; digestibility; cattle Submission: February 10, 2012 Corrected : March 13, 2013 Accepted: March 29, 2013 Doi: 10.12777/ijse.4.2.2013.86-91 [How to cite this article: Mayulu, H., Sunarso, S., Christiyanto, M. and Ballo, F. (2013). Intake and Digestibility of Cattle’s Ration On Complete Feed Based-On Fermented Ammonization Rice Straw With Different Protein Level. International Journal of Science and Engineering, 4(2),86-91. Doi: 10.12777/ijse.4.2.2013.86-91] I. INTRODUCTION Livestock development especially for beef cattle breeding needs to be done through sustained effort, modern and professional by utilizing technological innovation to improve its business efficiency. The successful development of beef cattle is determined by the sufficient of food both in quantity and quality. Forage as major component of feed is derived from grazing land and other sources. Moreover, the development of beef cattle should be supported by industry which optimizes the utilization of local resources through an integrated pattern. That condition reflects the importance of crops and cattle integration. By product produced from plantation and crop could be source for livestock ration by improving their nutritional ingredients (Mathius and Sinurat, 2001; Nkrumah et al., 2006; Diwyanto, 2008; Mathius, 2008; Muyulu et al., 2010; Kuswandi, 2011). Ration technology is growing year to year such as complete feed (CF) for beef cattle. Complete feed provides sufficient nutrients for beef cattle in certain physiological level. CF is fed for beef cattle as the only feed which enables to meet the basic needs of life and production without the addition of other materials except water. The use of CF in beef cattle breeding can produce high productivity, so it is believed that the use of CF will give more efficiency both technically and economically (Hartadi et al., 1997; Mayulu, et al., 2009; Sunarso et al., 2011; Mayulu et al., 2012). Rice straw is by-product of paddy plant which has potential source for fiber needs of beef cattle. Utilization of